Sample records for ignition system spark

  1. Investigation of spark discharge processes and ignition systems for spark-ignited internal combustion engines

    E-Print Network [OSTI]

    Khare, Yogesh Jayant

    2000-01-01T23:59:59.000Z

    includes an evaluation of the various types of conventional as well as high-energy ignition systems for lean burn engines. An experimental ignition system was constructed to determine the effect of ignition energy, spark plug electrode geometry and gas...

  2. Low current extended duration spark ignition system

    DOE Patents [OSTI]

    Waters, Stephen Howard; Chan, Anthony Kok-Fai

    2005-08-30T23:59:59.000Z

    A system for firing a spark plug is disclosed. The system includes a timing controller configured to send a first timing signal and a second timing signal. The system also includes an ignition transformer having a primary winding and a secondary winding and a spark-plug that is operably associated with the secondary winding. A first switching element is disposed between the timing controller and the primary winding of the ignition transformer. The first switching element controls a supply of power to the primary winding based on the first timing signal. Also, a second switching element is disposed between the timing controller and the primary winding of the ignition transformer. The second switching element controls the supply of power to the primary winding based on the second timing signal. A method for firing a spark plug is also disclosed.

  3. Laser spark distribution and ignition system

    DOE Patents [OSTI]

    Woodruff, Steven (Morgantown, WV); McIntyre, Dustin L. (Morgantown, WV)

    2008-09-02T23:59:59.000Z

    A laser spark distribution and ignition system that reduces the high power optical requirements for use in a laser ignition and distribution system allowing for the use of optical fibers for delivering the low peak energy pumping pulses to a laser amplifier or laser oscillator. An optical distributor distributes and delivers optical pumping energy from an optical pumping source to multiple combustion chambers incorporating laser oscillators or laser amplifiers for inducing a laser spark within a combustion chamber. The optical distributor preferably includes a single rotating mirror or lens which deflects the optical pumping energy from the axis of rotation and into a plurality of distinct optical fibers each connected to a respective laser media or amplifier coupled to an associated combustion chamber. The laser spark generators preferably produce a high peak power laser spark, from a single low power pulse. The laser spark distribution and ignition system has application in natural gas fueled reciprocating engines, turbine combustors, explosives and laser induced breakdown spectroscopy diagnostic sensors.

  4. Laser spark distribution and ignition system - Energy Innovation...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    power pulse. The laser spark distribution and ignition system has application in natural gas fueled reciprocating engines, turbine combustors, explosives and laser induced...

  5. Laser Spark Distribution and Ignition System

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    laser spark from a single low power pulse. The system has ap- plications in natural gas fueled reciprocating engines, turbine combustors, explosives, and laser induced...

  6. Managing transient behaviors of a dual mode spark ignition-- controlled auto ignition engine with a variable valve timing system

    E-Print Network [OSTI]

    Santoso, Halim G. (Halim Gustiono), 1975-

    2005-01-01T23:59:59.000Z

    Gasoline Homogeneous Charge Compression Ignition (HCCI) engine has the potential of providing better fuel economy and emissions characteristics than current spark ignition engines. One implementation of this technology ...

  7. Chaotic Combustion in Spark Ignition Engines

    E-Print Network [OSTI]

    M. Wendeker; J. Czarnigowski; G. Litak; K. Szabelski

    2002-12-27T23:59:59.000Z

    We analyse the combustion process in a spark ignition engine using the experimental data of an internal pressure during the combustion process and show that the system can be driven to chaotic behaviour. Our conclusion is based on the observation of unperiodicity in the time series, suitable stroboscopic maps and a complex structure of a reconstructed strange attractor. This analysis can explain that in some circumstances the level of noise in spark ignition engines increases considerably due to nonlinear dynamics of a combustion process.

  8. Improving the Efficiency of Spark Ignited, Stoichiometric Natural...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Spark Ignited, Stoichiometric Natural Gas Engines Improving the Efficiency of Spark Ignited, Stoichiometric Natural Gas Engines This work focused on using camless engine technology...

  9. Simulation of turbulent flames relevant to spark-ignition engines

    E-Print Network [OSTI]

    Ahmed, Irufan

    2014-04-29T23:59:59.000Z

    -premixed. In premixed flames, fuel and oxidiser are mixed homo- geneously before combustion. Lean-burn gas turbines for power generation and spark-ignition (SI) IC engines are typical examples of this type of combustion. In non-premixed or ‘diffusion flames’, the fuel... and oxidiser are transported sep- arately into the reaction zones by diffusion. Aero-engine gas turbines and diesel engines are typical examples of non-premixed combustion. It is often the case in practical systems that fuel and air is not completely mixed...

  10. Signal Analysis of Automotive Engine Spark Ignition System using Case-Based Reasoning (CBR) and Case-based Maintenance (CBM)

    SciTech Connect (OSTI)

    Huang, H.; Vong, C. M. [Department of Computer and Information Science, FST, University of Macau (China); Wong, P. K. [Department of Electromechanical Engineering, FST, University of Macau (China)

    2010-05-21T23:59:59.000Z

    With the development of modern technology, modern vehicles adopt electronic control system for injection and ignition. In traditional way, whenever there is any malfunctioning in an automotive engine, an automotive mechanic usually performs a diagnosis in the ignition system of the engine to check any exceptional symptoms. In this paper, we present a case-based reasoning (CBR) approach to help solve human diagnosis problem. Nevertheless, one drawback of CBR system is that the case library will be expanded gradually after repeatedly running the system, which may cause inaccuracy and longer time for the CBR retrieval. To tackle this problem, case-based maintenance (CBM) framework is employed so that the case library of the CBR system will be compressed by clustering to produce a set of representative cases. As a result, the performance (in retrieval accuracy and time) of the whole CBR system can be improved.

  11. Combustion Process in a Spark Ignition Engine: Dynamics and Noise Level Estimation

    E-Print Network [OSTI]

    T. Kaminski; M. Wendeker; K. Urbanowicz; G. Litak

    2003-12-28T23:59:59.000Z

    We analyse the experimental time series of internal pressure in a four cylinder spark ignition engine. In our experiment, performed for different spark advance angles, apart from usual cyclic changes of engine pressure we observed oscillations. These oscillations are with longer time scales ranging from one to several hundred engine cycles depending on engine working conditions. Basing on the pressure time dependence we have calculated the heat released per cycle. Using the time series of heat release to calculate the correlation coarse-grained entropy we estimated the noise level for internal combustion process. Our results show that for a smaller spark advance angle the system is more deterministic.

  12. Control-Oriented Model of a Dual Equal Variable Cam Timing Spark Ignition Engine

    E-Print Network [OSTI]

    Stefanopoulou, Anna

    control 1 Introduction. Modern automobile engines must satisfy the challenging and often con icting goals) 248-3611, Phone: (313) 322-1977 y Control Systems Laboratory, Department of Electrical EngineeringControl-Oriented Model of a Dual Equal Variable Cam Timing Spark Ignition Engine A. G

  13. Burner ignition system

    DOE Patents [OSTI]

    Carignan, Forest J. (Bedford, MA)

    1986-01-21T23:59:59.000Z

    An electronic ignition system for a gas burner is battery operated. The battery voltage is applied through a DC-DC chopper to a step-up transformer to charge a capacitor which provides the ignition spark. The step-up transformer has a significant leakage reactance in order to limit current flow from the battery during initial charging of the capacitor. A tank circuit at the input of the transformer returns magnetizing current resulting from the leakage reactance to the primary in succeeding cycles. An SCR in the output circuit is gated through a voltage divider which senses current flow through a flame. Once the flame is sensed, further sparks are precluded. The same flame sensor enables a thermopile driven main valve actuating circuit. A safety valve in series with the main gas valve responds to a control pressure thermostatically applied through a diaphragm. The valve closes after a predetermined delay determined by a time delay orifice if the pilot gas is not ignited.

  14. Control strategy for hydrocarbon emissions in turbocharged direct injection spark ignition engines during cold-start

    E-Print Network [OSTI]

    Cedrone, Kevin David

    2013-01-01T23:59:59.000Z

    Gasoline consumption and pollutant emissions from transportation are costly and have serious, demonstrated environmental and health impacts. Downsized, turbocharged direct-injection spark ignition (DISI) gasoline engines ...

  15. An ignition and combustion model based on the level-set method for spark ignition engine multidimensional modeling

    SciTech Connect (OSTI)

    Tan, Zhichao; Reitz, Rolf D. [Engine Research Center, University of Wisconsin-Madison, 1500 Engineering Drive, Madison, WI 53706 (United States)

    2006-04-15T23:59:59.000Z

    To improve the prediction accuracy of the spark ignition and combustion processes in spark ignition engines, improved ignition and flame propagation models have been developed and implemented in the CFD code, KIVA-3V. An equation to calculate the spark ignition kernel growth rate is derived that considers the effects of the spark ignition discharge energy and flow turbulence on the ignition kernel growth. In addition, a flamelet combustion model based on the G equation combustion model was developed and implemented. To test the ignition and combustion models, they were applied to a homogeneous charge pancake-shaped-combustion-chamber engine, in which experimental heat flux data from probes in the engine head and cylinder liner were available. By comparing the flame arrival timings with the simulation predictions, the ignition and combustion models were validated. In addition, the models were also applied to a homogeneous charge propane-fueled SI engine. Good agreement with experimental cylinder pressures and NO{sub x} data was obtained as a function of ignition timing, engine speed, and EGR levels. (author)

  16. A multi-mode combustion diagram for spark assisted compression ignition

    SciTech Connect (OSTI)

    Lavoie, George A.; Martz, J.; Wooldridge, M.; Assanis, D. [University of Michigan, Mechanical Engineering Department, Ann Arbor, MI 48109 (United States)

    2010-06-15T23:59:59.000Z

    The potential utility of spark discharges to assist low temperature, compression ignited engines has resulted in a number of experimental studies. These show mixed results; sometimes spark is effective at controlling heat release timing, sometimes it only stabilizes combustion, and sometimes it has no effect at all. In order to help understand the spark assisted process we propose a multi-mode combustion diagram to delineate the regimes of spark ignition, flame propagation, compression ignition, knocking combustion and spark-assisted combustion, in terms of unburned and burned gas temperatures near top dead center. An analysis of existing experimental data suggests that the effectiveness of spark assist is best at higher and middle loads and decreases as load is reduced. (author)

  17. Modeling and Control of a Spark Ignition Engine with Variable Cam Timing A. G. Stefanopoulou, J. A. Cooky

    E-Print Network [OSTI]

    Stefanopoulou, Anna

    and multivariable. The control scheme jointly manages fuel and cam position. 1 Introduction. Modern automobile external exhaust gas recirculation (EGR) systems commonly used for NOx reduction. Control SystemsModeling and Control of a Spark Ignition Engine with Variable Cam Timing A. G. Stefanopoulou, J. A

  18. Assessing the hydrocarbon emissions in a homogeneous direct injection spark ignited engine

    E-Print Network [OSTI]

    Radovanovic, Michael S

    2006-01-01T23:59:59.000Z

    For the purpose of researching hydrocarbon (HC) emissions in a direct-injection spark ignited (DISI) engine, five experiments were performed. These experiments clarified the role of coolant temperature, injection pressure, ...

  19. Soot formation in direct injection spark ignition engines under cold-idle operating conditions

    E-Print Network [OSTI]

    Ketterer, Justin Edward

    2013-01-01T23:59:59.000Z

    Direct injection spark ignition engines are growing rapidly in popularity, largely due to the fuel efficiency improvements in the turbo-downsized engine configuration that are enabled by direct injection technology. ...

  20. Use of a Thermodynamic Engine Cycle Simulation to Study a Turbocharged Spark-ignition Engine

    E-Print Network [OSTI]

    Lawand, Vaibhav

    2010-07-14T23:59:59.000Z

    to examine the turbocharged spark-ignition engines in greater detail using second law analyses as they are gaining popularity in high performance and conventional automobiles as well. A thermodynamic simulation was developed in order to investigate...

  1. A visualization study of mixture preparation mechanisms for port fuel injected spark ignition engines

    E-Print Network [OSTI]

    Costanzo, Vincent S. (Vincent Stanley), 1979-

    2004-01-01T23:59:59.000Z

    An experimental study was carried out that examined qualitatively the mixture preparation process in port fuel injected spark ignition engines. The primary variables in this study were intake valve lift, intake valve timing, ...

  2. Dynamic instabilities in spark-ignited combustion engines with high exhaust gas recirculation

    SciTech Connect (OSTI)

    Daw, C Stuart [ORNL] [ORNL; FINNEY, Charles E A [ORNL] [ORNL

    2011-01-01T23:59:59.000Z

    We propose a cycle-resolved dynamic model for combustion instabilities in spark-ignition engines operating with high levels of exhaust gas recirculation (EGR). High EGR is important for increasing fuel efficiency and implementing advanced low-emission combustion modes such as homogenous charge compression ignition (HCCI). We account for the complex combustion response to cycle-to-cycle feedback by utilizing a global probability distribution that describes the pre-spark state of in-cylinder fuel mixing. The proposed model does a good job of simulating combustion instabilities observed in both lean-fueling engine experiments and in experiments where nitrogen dilution is used to simulate some of the combustion inhibition of EGR. When used to simulate high internal EGR operation, the model exhibits a range of global bifurcations and chaos that appear to be very robust. We use the model to show that it should be possible to reduce high EGR combustion instabilities by switching from internal to external EGR. We also explain why it might be helpful to deliberately stratify the fuel in the pre-spark gas mixture. It might be possible to extend the simple approach used in this model to other chemical reaction systems with spatial inhomogeneity.

  3. Thermal ignition combustion system

    DOE Patents [OSTI]

    Kamo, R.; Kakwani, R.M.; Valdmanis, E.; Woods, M.E.

    1988-04-19T23:59:59.000Z

    The thermal ignition combustion system comprises means for providing walls defining an ignition chamber, the walls being made of a material having a thermal conductivity greater than 20 W/m C and a specific heat greater than 480 J/kg C with the ignition chamber being in constant communication with the main combustion chamber, means for maintaining the temperature of the walls above a threshold temperature capable of causing ignition of a fuel, and means for conducting fuel to the ignition chamber. 8 figs.

  4. A user-friendly computer simulation of a spark ignition engine

    E-Print Network [OSTI]

    Berrios, Ivan

    1993-01-01T23:59:59.000Z

    . This simulation is not intended for more specific engine characteristics such as combustion chamber geometry, inlet manifold design, spark-plug placement and the like. This research is an extension of the work done in MEEN 410 "Internal Coinbustion Engines...A USER-FRIENDLY COMPUTER SIMULATION OF A SPARK IGNITION ENGINE A Thesis by IVAN BERRIOS Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE...

  5. Phenomena that determine knock onset in spark-ignited engines

    E-Print Network [OSTI]

    Revier, Bridget M. (Bridget Mary)

    2006-01-01T23:59:59.000Z

    Experiments were carried out to collect in-cylinder pressure data and microphone signals from a single-cylinder test engine using spark timings before, at, and after knock onset for four different octane-rated toluene ...

  6. Development of High Efficiency Clean Combustion Engine Designs for Spark-Ignition and Compression-Ignition Internal Combustion Engines

    SciTech Connect (OSTI)

    Marriott, Craig; Gonzalez, Manual; Russell, Durrett

    2011-06-30T23:59:59.000Z

    This report summarizes activities related to the revised STATEMENT OF PROJECT OBJECTIVES (SOPO) dated June 2010 for the Development of High-Efficiency Clean Combustion engine Designs for Spark-Ignition and Compression-Ignition Internal Combustion Engines (COOPERATIVE AGREEMENT NUMBER DE-FC26-05NT42415) project. In both the spark- (SI) and compression-ignition (CI) development activities covered in this program, the goal was to develop potential production-viable internal combustion engine system technologies that both reduce fuel consumption and simultaneously met exhaust emission targets. To be production-viable, engine technologies were also evaluated to determine if they would meet customer expectations of refinement in terms of noise, vibration, performance, driveability, etc. in addition to having an attractive business case and value. Prior to this activity, only proprietary theoretical / laboratory knowledge existed on the combustion technologies explored The research reported here expands and develops this knowledge to determine series-production viability. Significant SI and CI engine development occurred during this program within General Motors, LLC over more than five years. In the SI program, several engines were designed and developed that used both a relatively simple multi-lift valve train system and a Fully Flexible Valve Actuation (FFVA) system to enable a Homogeneous Charge Compression Ignition (HCCI) combustion process. Many technical challenges, which were unknown at the start of this program, were identified and systematically resolved through analysis, test and development. This report documents the challenges and solutions for each SOPO deliverable. As a result of the project activities, the production viability of the developed clean combustion technologies has been determined. At this time, HCCI combustion for SI engines is not considered production-viable for several reasons. HCCI combustion is excessively sensitive to control variables such as internal dilution level and charge temperature. As a result, HCCI combustion has limited robustness when variables exceed the required narrow ranges determined in this program. HCCI combustion is also not available for the entire range of production engine speeds and loads, (i.e., the dynamic range is limited). Thus, regular SI combustion must be employed for a majority of the full dynamic range of the engine. This degrades the potential fuel economy impact of HCCI combustion. Currently-available combustion control actuators for the simple valve train system engine do not have the authority for continuous air - fuel or torque control for managing the combustion mode transitions between SI and HCCI and thus, require further refinement to meet customer refinement expectations. HCCI combustion control sensors require further development to enable robust long-term HCCI combustion control. Finally, the added technologies required to effectively manage HCCI combustion such as electric cam phasers, central direct fuel injection, cylinder pressure sensing, high-flow exhaust gas recirculation system, etc. add excessive on-engine cost and complexity that erodes the production-viability business

  7. Fiber laser coupled optical spark delivery system

    DOE Patents [OSTI]

    Yalin, Azer (Fort Collins, CO); Willson, Bryan (Fort Collins, CO); Defoort, Morgan (Fort Collins, CO); Joshi, Sachin (Fort Collins, CO); Reynolds, Adam (Fort Collins, CO)

    2008-03-04T23:59:59.000Z

    A spark delivery system for generating a spark using a laser beam is provided, and includes a laser light source and a laser delivery assembly. The laser delivery assembly includes a hollow fiber and a launch assembly comprising launch focusing optics to input the laser beam in the hollow fiber. The laser delivery assembly further includes exit focusing optics that demagnify an exit beam of laser light from the hollow fiber, thereby increasing the intensity of the laser beam and creating a spark. Other embodiments use a fiber laser to generate a spark. Embodiments of the present invention may be used to create a spark in an engine. Yet other embodiments include collecting light from the spark or a flame resulting from the spark and conveying the light for diagnostics. Methods of using the spark delivery systems and diagnostic systems are provided.

  8. Cyclic Variability During the Transition Between Spark-ignited Combustion and HCCI

    SciTech Connect (OSTI)

    Edwards, Kevin Dean [ORNL; Daw, C Stuart [ORNL; Wagner, Robert M [ORNL; Green Jr, Johney Boyd [ORNL

    2006-01-01T23:59:59.000Z

    Experimental observations of cyclic variability are described for the transition between conventional spark-ignited (SI) propagating-flame combustion and homogeneous charge compression ignition (HCCI) combustion in a single-cylinder, stoichiometrically fueled, gasoline engine. The engine under study is equipped with a fully variable valve actuation (VVA) system which was used to control the levels of internal exhaust gas recirculation (EGR) to achieve the transition from conventional SI to HCCI. Engine operation in both SI and HCCI modes was observed to be very stable with only minor, stochastic cyclic variability. However, during transitions between these modes, operation was observed to be highly unstable with high levels of cyclic variability and occasionally the engine could not sustain combustion. Analysis of the observed cyclic variability suggests that the transition between SI and HCCI can be described as a sequence of bifurcations in a low-dimensional dynamic map. The deterministic nature of the instabilities observed during the transition suggest that it is possible to make accurate, short-term predictions of combustion performance allowing for the possibility of developing on-line diagnostics and proactive control algorithms for expanding stable HCCI operation and improving transitions between conventional combustion modes and HCCI.

  9. Fiber coupled optical spark delivery system

    DOE Patents [OSTI]

    Yalin, Azer (Fort Collins, CO); Willson, Bryan (Fort Collins, CO); Defoort, Morgan (Fort Collins, CO)

    2008-08-12T23:59:59.000Z

    A spark delivery system for generating a spark using a laser beam is provided, the spark delivery system including a laser light source and a laser delivery assembly. The laser delivery assembly includes a hollow fiber and a launch assembly comprising launch focusing optics to input the laser beam in the hollow fiber. In addition, the laser delivery assembly includes exit focusing optics that demagnify an exit beam of laser light from the hollow fiber, thereby increasing the intensity of the laser beam and creating a spark. In accordance with embodiments of the present invention, the assembly may be used to create a spark in a combustion engine. In accordance with other embodiments of the present invention, a method of using the spark delivery system is provided. In addition, a method of choosing an appropriate fiber for creating a spark using a laser beam is also presented.

  10. Particulate Matter Emissions from a Direct Injection Spark Ignition Engine under Cold Fast Idle Conditions for Ethanol-Gasoline Blends

    E-Print Network [OSTI]

    Dimou, Iason

    The engine out particular matter number (PN) distributions at engine coolant temperature (ECT) of 0° C to 40° C for ethanol/ gasoline blends (E0 to E85) have been measured for a direct-injection spark ignition engine under ...

  11. Reducing cold start hydrocarbon emissions from port fuel injected spark ignition engines with improved management of hardware & controls

    E-Print Network [OSTI]

    Lang, Kevin R., 1980-

    2006-01-01T23:59:59.000Z

    An experimental study was performed to investigate strategies for reducing cold start hydrocarbon (HC) emissions from port fuel injected (PFI) spark ignition (SI) engines with better use of existing hardware and control ...

  12. Effect of fuel properties on the first cycle fuel delivery in a Port Fuel Injected Spark Ignition Engine

    E-Print Network [OSTI]

    Lang, Kevin R., 1980-

    2004-01-01T23:59:59.000Z

    Achieving robust combustion while also yielding low hydrocarbon (HC) emissions is difficult for the first cycle of cranking during the cold start of a Port Fuel Injected (PFI) Spark Ignition (SI) engine. Cold intake port ...

  13. Organic gas emissions from a stoichiometric direct injection spark ignition engine operating on ethanol/gasoline blends

    E-Print Network [OSTI]

    Kar, Kenneth

    The organic gas emissions from a stoichiometric direct injection spark ignition engine operating on ethanol/gasoline blends have been assessed under warmed-up and cold idle conditions. The speciated emissions show that the ...

  14. The effects of spark ignition parameters on the lean burn limit of natural gas combustion in an internal combustion engine

    E-Print Network [OSTI]

    Chlubiski, Vincent Daniel

    1997-01-01T23:59:59.000Z

    A full factorial experiment was conducted to determine the effects of internal combustion engine ignition parameters on the air-fuel ratio (A/F) lean limit of combustion with compressed natural gas (CNG). Spark electrical characteristics (voltage...

  15. An analytical investigation of the effects of water injection on combustion products and detonation in spark ignition engines

    E-Print Network [OSTI]

    Brown, William Charles

    1979-01-01T23:59:59.000Z

    AN ANALYTICAL INVESTIGATION OF THE EFFECTS OF WATER INJECTION ON COMBUSTION PRODUCTS AND DETONATION IN SPARK IGNITION ENGINES A Thesis by WILIIAM CHARLES BROWN Submitted to the Graduate College of Texas ANNI University in partial fulfillment... of the requirement for the degree of MASTER OF SCIENCE August 1979 Major Subject: Aerospace Engineering AN ANALYTICAL INVESTIGATION Ol' THE El'FECTS OF WATER INJECTION ON COMBUSTION PRODUCTS AND DETONATION IN SPARK IGNITION ENGINES A Thesis by WILLIAM...

  16. Combustion Process in a Spark Ignition Engine: Analysis of Cyclic Maximum Pressure and Peak Pressure Angle

    E-Print Network [OSTI]

    G. Litak; T. Kaminski; J. Czarnigowski; A. K. Sen; M. Wendeker

    2006-11-29T23:59:59.000Z

    In this paper we analyze the cycle-to-cycle variations of maximum pressure $p_{max}$ and peak pressure angle $\\alpha_{pmax}$ in a four-cylinder spark ignition engine. We examine the experimental time series of $p_{max}$ and $\\alpha_{pmax}$ for three different spark advance angles. Using standard statistical techniques such as return maps and histograms we show that depending on the spark advance angle, there are significant differences in the fluctuations of $p_{max}$ and $\\alpha_{pmax}$. We also calculate the multiscale entropy of the various time series to estimate the effect of randomness in these fluctuations. Finally, we explain how the information on both $p_{max}$ and $\\alpha_{pmax}$ can be used to develop optimal strategies for controlling the combustion process and improving engine performance.

  17. Railplug Ignition System for Enhanced Engine Performance and Reduced Maintenance

    SciTech Connect (OSTI)

    DK Ezekoye; Matt Hall; Ron Matthews

    2005-08-01T23:59:59.000Z

    This Final Technical Report discusses the progress that was made on the experimental and numerical tasks over the duration of this project. The primary objectives of the project were to (1) develop an improved understanding of the spark ignition process, and (2) develop the railplug as an improved ignitor for large bore stationary natural gas engines. We performed fundamental experiments on the physical processes occurring during spark ignition and used the results from these experiments to aid our development of the most complete model of the spark ignition process ever devised. The elements in this model include (1) the dynamic response of the ignition circuit, (2) a chemical kinetics mechanism that is suitable for the reactions that occur in the plasma, (3) conventional flame propagation kinetics, and (4) a multi-dimensional formulation so that bulk flow through the spark gap can be incorporated. This model (i.e., a Fortran code that can be used as a subroutine within an engine modeling code such as KIVA) can be obtained from Prof. Ron Matthews at rdmatt{at}mail.utexas.edu or Prof. DK Ezekoye at dezekoye{at}mail.utexas.edu. Fundamental experiments, engine experiments, and modeling tasks were used to help develop the railplug as a new ignitor for large bore natural gas engines. As the result of these studies, we developed a railplug that could extend the Lean Stability Limit (LSL) of an engine operating at full load on natural gas from {phi} = 0.59 for operation on spark plugs down to {phi} = 0.53 using railplugs with the same delivered energy (0.7 J). However, this delivered energy would rapidly wear out the spark plug. For a conventional delivered energy (<0.05 J), the LSL is {phi} = 0.63 for a spark plug. Further, using a permanent magnet to aid the plasma movement, the LSL was extended to {phi} = 0.54 for a railplug with a delivered energy of only 0.15 J/shot, a typical discharge energy for commercial capacitive discharge ignition systems. Here, it should be noted that railplugs and the associated ignition circuit should not cost much more than a conventional spark ignition system. Additionally, it is believed that the railplug performance can be further improved via continued research and development.

  18. Cycle-to-Cycle Fluctuations of Burned Fuel Mass in Spark Ignition Combustion Engines

    E-Print Network [OSTI]

    M. Wendeker; G. Litak; M. Krupa

    2003-12-28T23:59:59.000Z

    We examine a simple, fuel-air, model of combustion in spark ignition (si) engine with indirect injection. In our two fluid model, variations of fuel mass burned in cycle sequences appear due to stochastic fluctuations of a fuel feed amount. We have shown that a small amplitude of these fluctuations affects considerably the stability of a combustion process strongly depending on the quality of air-fulel mixture. The largest influence was found in the limit of a lean combustion. The possible effect of nonlinearities in the combustion process were also discussed.

  19. EBDI® - Application of a High BMEP Downsized Spark Ignited Engine |

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny:Revised Finding of98-F, Western Systems Power PoolOctober 17, 2012of5,

  20. Towards the understanding of cyclic variability in a spark ignited engine using multi-cycle LES

    SciTech Connect (OSTI)

    Vermorel, O.; Richard, S.; Colin, O.; Angelberger, C.; Benkenida, A. [IFP, 1 and 4 Avenue de Bois-Preau, 92852 Rueil-Malmaison Cedex (France); Veynante, D. [EM2C, CNRS and Ecole Centrale Paris, Grande Voie des Vignes, 92295 Chatenay-Malabry (France)

    2009-08-15T23:59:59.000Z

    Large-Eddy Simulation (LES) has been used to analyze the occurrence and the causes of cycle-to-cycle combustion variations in a spark ignited four-valve single cylinder engine fueled with a homogeneous propane-air mixture. The combustion modeling combines an Eulerian model derived from the RANS AKTIM model that mimics the spark ignition and the Extended Coherent Flame Model (ECFM-LES) that describes the flame propagation. The motion of piston and valves is accounted for using an Arbitrary Eulerian Lagrangian (ALE) technique with body-fitted meshes. The computation covers nine consecutive complete four-stroke cycles following an initialization cycle. The obtained LES results are compared with experimental measurements. Although the number of computed cycles is fairly low, LES is shown to be able to reproduce both quantitatively and qualitatively the cyclic variability observed experimentally. The investigation of the possible causes of variability illustrates the unprecedented possibility LES offers for understanding cycle-to-cycle variations. (author)

  1. Premix charge, compression ignition combustion system optimization...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Premix charge, compression ignition combustion system optimization Premix charge, compression ignition combustion system optimization Presentation given at DEER 2006, August 20-24,...

  2. Multi-timescale modeling of ignition and flame regimes of n-heptane-air mixtures near spark assisted homogeneous charge compression ignition conditions

    SciTech Connect (OSTI)

    Ju, Yiguang; Sun, Wenting; Burke, M. P.; Gou, Xiaolong; Chen, Zheng

    2011-01-01T23:59:59.000Z

    The flame regimes of ignition and flame propagation as well as transitions between different flame regimes of n-heptane-air mixtures in a one-dimensional, cylindrical, spark assisted homogeneously charged compression ignition (HCCI) reactor are numerically modeled using a multi-timescale method with reduced kinetic mechanism. It is found that the initial mixture temperature and pressure have a dramatic impact on flame dynamics. Depending on the initial temperature gradient, there exist at least six different combustion regimes, an initial single flame front propagation regime, a coupled low temperature and high temperature double-flame regime, a decoupled low temperature and high temperature double-flame regime, a low temperature ignition regime, a single high temperature flame regime, and a hot ignition regime. The results show that the low temperature and high temperature flames have distinct kinetic and transport properties as well as flame speeds, and are strongly influenced by the low temperature chemistry. The pressure and heat release rates are affected by the appearance of different flame regimes and the transitions between them. Furthermore, it is found that the critical temperature gradient for ignition and acoustic wave coupling becomes singular at the negative temperature coefficient (NTC) region. The results show that both the NTC effect and the acoustic wave propagation in a closed reactor have a dramatic impact on the ignition front and acoustic interaction.

  3. Optical diagnostics integrated with laser spark delivery system

    DOE Patents [OSTI]

    Yalin, Azer (Fort Collins, CO); Willson, Bryan (Fort Collins, CO); Defoort, Morgan (Fort Collins, CO); Joshi, Sachin (Fort Collins, CO); Reynolds, Adam (Fort Collins, CO)

    2008-09-02T23:59:59.000Z

    A spark delivery system for generating a spark using a laser beam is provided, and includes a laser light source and a laser delivery assembly. The laser delivery assembly includes a hollow fiber and a launch assembly comprising launch focusing optics to input the laser beam in the hollow fiber. The laser delivery assembly further includes exit focusing optics that demagnify an exit beam of laser light from the hollow fiber, thereby increasing the intensity of the laser beam and creating a spark. Other embodiments use a fiber laser to generate a spark. Embodiments of the present invention may be used to create a spark in an engine. Yet other embodiments include collecting light from the spark or a flame resulting from the spark and conveying the light for diagnostics. Methods of using the spark delivery systems and diagnostic systems are provided.

  4. Characterizing dilute combustion instabilities in a multi-cylinder spark-ignited engine using symbolic analysis

    SciTech Connect (OSTI)

    Daw, C Stuart [ORNL; FINNEY, Charles E A [ORNL; Kaul, Brian C [ORNL; Edwards, Kevin Dean [ORNL; Wagner, Robert M [ORNL

    2015-01-01T23:59:59.000Z

    Spark-ignited internal combustion engines have evolved considerably in recent years in response to increasingly stringent regulations for emissions and fuel-economy. One new advanced engine strategy utilizes high levels of exhaust gas recirculation (EGR) to reduce combustion temperatures, thereby increasing thermodynamic efficiency and reducing nitrogen oxide emissions. While this strategy can be highly effective, it also poses major control and design challenges due to the large combustion oscillations that develop at sufficiently high EGR levels. Previous research has documented that combustion instabilities can propagate between successive engine cycles in individual cylinders via self-generated feedback of reactive species and thermal energy in the retained residual exhaust gases. In this work, we use symbolic analysis to characterize multi-cylinder combustion oscillations in an experimental engine operating with external EGR. At low levels of EGR, intra-cylinder oscillations are clearly visible and appear to be associated with brief, intermittent coupling among cylinders. As EGR is increased further, a point is reached where all four cylinders lock almost completely in phase and alternate simultaneously between two distinct bi-stable combustion states. From a practical perspective, it is important to understand the causes of this phenomenon and develop diagnostics that might be applied to ameliorate its effects. We demonstrate here that two approaches for symbolizing the engine combustion measurements can provide useful probes for characterizing these instabilities.

  5. Characteristics of cyclic heat release variability in the transition from spark ignition to HCCI in a gasoline engine

    SciTech Connect (OSTI)

    Sen, Asok K [Indiana University; Litak, Grzegorz [Technical University of Lublin; Edwards, Kevin Dean [ORNL; FINNEY, Charles E A [ORNL; Daw, C Stuart [ORNL; Wagner, Robert M [ORNL

    2011-01-01T23:59:59.000Z

    We study selected examples of previously published cyclic heat-release measurements from a single-cylinder gasoline engine as stepwise valve timing adjustments were made to shift from spark ignited (SI) combustion to homogeneous charge compression ignition (HCCI). Wavelet analysis of the time series, combined with conventional statistics and multifractal analysis, revealed previously undocumented features in the combustion variability as the shift occurred. In the spark-ignition combustion mode, the heat-release variations were very small in amplitude and exhibited more persistent low-frequency oscillations with intermittent high-frequency bursts. In the HCCI combustion mode, the amplitude of the heat-release variations again was small and involved mainly low-frequency oscillations. At intermediate states between SI and HCCI, a wide range of very large-amplitude oscillations occurred, including both persistent low-frequency periodicities and intermittent high-frequency bursts. It appears from these results that real-time wavelet decomposition of engine cylinder pressure measurements may be useful for on-board tracking of SI HCCI combustion regime shifts.

  6. CYCLE-BY-CYCLE COMBUSTION VARIATIONS IN SPARK-IGNITED ENGINES Engineering Technology Division, Oak Ridge National Laboratory, Oak Ridge TN 37831-8088 USA

    E-Print Network [OSTI]

    Tennessee, University of

    -2053 USA ABSTRACT Under constant nominal operating conditions, internal combustion engines can exhibit sub Introduction Under constant nominal operating conditions, internal combustion engines can exhibit substantialCYCLE-BY-CYCLE COMBUSTION VARIATIONS IN SPARK-IGNITED ENGINES C.S. DAW Engineering Technology

  7. Utilizing a cycle simulation to examine the use of exhaust gas recirculation (EGR) for a spark-ignition engine: including the second law of thermodynamics

    E-Print Network [OSTI]

    Shyani, Rajeshkumar Ghanshyambhai

    2008-10-10T23:59:59.000Z

    , the optimum EGR rate should be carefully determined in order to obtain the better engine performance and emissions. A thermodynamic cycle simulation of the four-stroke spark-ignition engine was used to determine the effects of EGR on engine performance...

  8. Control of Thermal Ignition in Gasoline Engines C. J. Chiang and A. G. Stefanopoulou

    E-Print Network [OSTI]

    Stefanopoulou, Anna

    (HCCI) en- gine, is fundamentally different from the spark ignition (SI) and the compression ignition

  9. Laser Spark Distribution and Ignition System - Energy Innovation Portal

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12electron 9 5 - -/e),,sandLaserLaser SeedingVehicles and

  10. FUSION IGNITION RESEARCH EXPERIMENT SYSTEM INTEGRATION *

    E-Print Network [OSTI]

    FUSION IGNITION RESEARCH EXPERIMENT SYSTEM INTEGRATION * T. Brown Princeton Plasma Physics-- This paper describes the current status of the FIRE configuration and the integration of the major subsystem vessel integrates cooling and shielding in a shape that maximizes shielding of ex-vessel components

  11. FUSION IGNITION RESEARCH EXPERIMENT SYSTEM INTEGRATION *

    E-Print Network [OSTI]

    FUSION IGNITION RESEARCH EXPERIMENT SYSTEM INTEGRATION * T. Brown Princeton Plasma Physics of the FIRE configuration and the integration of the major subsystem components. FIRE has a major by a thermal enclosure. The double wall vacuum vessel integrates cooling and shielding in a shape

  12. Chemical Kinetics of Hydrocarbon Ignition in Practical Combustion Systems

    SciTech Connect (OSTI)

    Westbrook, C.K.

    2000-07-07T23:59:59.000Z

    Chemical kinetic factors of hydrocarbon oxidation are examined in a variety of ignition problems. Ignition is related to the presence of a dominant chain branching reaction mechanism that can drive a chemical system to completion in a very short period of time. Ignition in laboratory environments is studied for problems including shock tubes and rapid compression machines. Modeling of the laboratory systems are used to develop kinetic models that can be used to analyze ignition in practical systems. Two major chain branching regimes are identified, one consisting of high temperature ignition with a chain branching reaction mechanism based on the reaction between atomic hydrogen with molecular oxygen, and the second based on an intermediate temperature thermal decomposition of hydrogen peroxide. Kinetic models are then used to describe ignition in practical combustion environments, including detonations and pulse combustors for high temperature ignition, and engine knock and diesel ignition for intermediate temperature ignition. The final example of ignition in a practical environment is homogeneous charge, compression ignition (HCCI) which is shown to be a problem dominated by the kinetics intermediate temperature hydrocarbon ignition. Model results show why high hydrocarbon and CO emissions are inevitable in HCCI combustion. The conclusion of this study is that the kinetics of hydrocarbon ignition are actually quite simple, since only one or two elementary reactions are dominant. However, there are many combustion factors that can influence these two major reactions, and these are the features that vary from one practical system to another.

  13. A Numerical Study of a Simple Stochastic/Deterministic Model of Cycle-to-Cycle Combustion Fluctuations in Spark Ignition Engines

    E-Print Network [OSTI]

    G. Litak; M. Wendeker; M. Krupa; J. Czarnigowski

    2004-05-23T23:59:59.000Z

    We examine a simple, fuel-air, model of combustion in a spark ignition (si) engine with indirect injection. In our two fluid model, variations of fuel mass burned in cycle sequences appear due to stochastic fluctuations of a fuel feed amount. We have shown that a small amplitude of these fluctuations affects considerably the stability of a combustion process strongly depending on the quality of air-fuel mixture. The largest influence was found in the limit of a lean combustion. The possible effect of nonlinearities in the combustion process has been also discussed.

  14. IMPROVEMENT TO PIPELINE COMPRESSOR ENGINE RELIABILITY THROUGH RETROFIT MICRO-PILOT IGNITION SYSTEM-PHASE I

    SciTech Connect (OSTI)

    Ted Bestor

    2003-03-04T23:59:59.000Z

    This report documents the first year's effort towards a 3-year program to develop micropilot ignition systems for existing pipeline compressor engines. In essence, all Phase I goals and objectives were met. We intend to proceed with the Phase II research plan, as set forth by the applicable Research Management Plan. The objective for Phase I was to demonstrate the feasibility of micropilot ignition for large bore, slow speed engines operating at low compression ratios. The primary elements of Micropilot Phase I were to develop a single-cylinder test chamber to study the injection of pilot fuel into a combustion cylinder and to develop, install and test a multi-cylinder micropilot ignition system for a 4-cylinder, natural gas test engine. In all, there were twelve (12) tasks defined and executed to support these two (2) primarily elements in a stepwise fashion. Task-specific approaches and results are documented in this report. Research activities for Micropilot Phase I were conducted with the understanding that the efforts are expected to result in a commercial product to capture and disseminate the efficiency and environmental benefits of this new technology. An extensive state-of-art review was conducted to leverage the existing body of knowledge of micropilot ignition with respect to retrofit applications. Additionally, commercially-available fuel injection products were identified and applied to the program where appropriate. This approach will minimize the overall time-to-market requirements, while meeting performance and cost criteria. The four-cylinder prototype data was encouraging for the micro-pilot ignition technology when compared to spark ignition. Initial testing results showed: (1) Brake specific fuel consumption of natural gas was improved from standard spark ignition across the map, 1% at full load and 5% at 70% load. (2) 0% misfires for all points on micropilot ignition. Fuel savings were most likely due to this percent misfire improvement. (3) THC (Total Hydrocarbon) emissions were improved significantly at light load, 38% at 70% load. (4) VOC (Volatile Organic Compounds) emissions were improved above 80% load. (5) Coefficient of Variance for the IMEP (Indicated Mean Effective Pressure) was significantly less at lower loads, 76% less at 70%. These preliminary results will be substantiated and enhanced during Phase II of the Micropilot Ignition program.

  15. Supervisory Control of Air-Fuel Ratio in Spark Ignition Engines

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    these control laws providing better performance of regulation. Results of implementation on two vehicles. There exist many good reasons and practical motivations to use a set of controllers to regulate a single plant and disadvantages of each subsys- tem for modeling and control is appearing. The theory of switched systems

  16. Ignitor with stable low-energy thermite igniting system

    DOE Patents [OSTI]

    Kelly, Michael D. (West Alexandria, OH); Munger, Alan C. (Miamisburg, OH)

    1991-02-05T23:59:59.000Z

    A stable compact low-energy igniting system in an ignitor utilizes two components, an initiating charge and an output charge. The initiating charge is a thermite in ultra-fine powder form compacted to 50-70% of theoretical maximum density and disposed in a cavity of a header of the ignitor adjacent to an electrical ignition device, or bridgewire, mounted in the header cavity. The initiating charge is ignitable by operation of the ignition device in a hot-wire mode. The output charge is a thermite in high-density consoladated form compacted to 90-99% of theoretical maximum density and disposed adjacent to the initiating charge on an opposite end thereof from the electrical ignition device and ignitable by the initiating charge. A sleeve is provided for mounting the output charge to the ignitor header with the initiating charge confined therebetween in the cavity.

  17. The spark counting of etched fission-fragment tracks in polycarbonate for a personal neutron dosimetry system

    E-Print Network [OSTI]

    Harrison, K G; Holt, P D; Wylie, J W

    1977-01-01T23:59:59.000Z

    The spark counting of etched fission-fragment tracks in polycarbonate for a personal neutron dosimetry system

  18. New Physics-Based Turbocharger Data-Maps Extrapolation Algorithms: Validation on a Spark-Ignited Engine

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    emissions of internal combustion engines. This can be achieved by reducing the engine displacement as well-Ignited Engine J. El Hadef *, **, G. Colin*, V.Talon**, Y.Chamaillard* *Laboratoire PRISME, 8 rue Léonard de.talon@renault.com) Abstract: Objectives in terms of pollutant emissions and fuel consumption reduction, as well as development

  19. Status Of The National Ignition Campaign And National Ignition Facility Integrated Computer Control System

    SciTech Connect (OSTI)

    Lagin, L; Brunton, G; Carey, R; Demaret, R; Fisher, J; Fishler, B; Ludwigsen, P; Marshall, C; Reed, R; Shelton, R; Townsend, S

    2011-03-18T23:59:59.000Z

    The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory is a stadium-sized facility that will contains a 192-beam, 1.8-Megajoule, 500-Terawatt, ultraviolet laser system together with a 10-meter diameter target chamber with room for multiple experimental diagnostics. NIF is the world's largest and most energetic laser experimental system, providing a scientific center to study inertial confinement fusion (ICF) and matter at extreme energy densities and pressures. NIF's laser beams are designed to compress fusion targets to conditions required for thermonuclear burn. NIF is operated by the Integrated Computer Control System (ICCS) in an object-oriented, CORBA-based system distributed among over 1800 frontend processors, embedded controllers and supervisory servers. In the fall of 2010, a set of experiments began with deuterium and tritium filled targets as part of the National Ignition Campaign (NIC). At present, all 192 laser beams routinely fire to target chamber center to conduct fusion and high energy density experiments. During the past year, the control system was expanded to include automation of cryogenic target system and over 20 diagnostic systems to support fusion experiments were deployed and utilized in experiments in the past year. This talk discusses the current status of the NIC and the plan for controls and information systems to support these experiments on the path to ignition.

  20. Detailed Chemical Kinetic Reaction Mechanisms for Primary Reference Fuels for Diesel Cetane Number and Spark-Ignition Octane Number

    SciTech Connect (OSTI)

    Westbrook, C K; Pitz, W J; Mehl, M; Curran, H J

    2010-03-03T23:59:59.000Z

    For the first time, a detailed chemical kinetic reaction mechanism is developed for primary reference fuel mixtures of n-hexadecane and 2,2,4,4,6,8,8-heptamethyl nonane for diesel cetane ratings. The mechanisms are constructed using existing rules for reaction pathways and rate expressions developed previously for the primary reference fuels for gasoline octane ratings, n-heptane and iso-octane. These reaction mechanisms are validated by comparisons between computed and experimental results for shock tube ignition and for oxidation under jet-stirred reactor conditions. The combined kinetic reaction mechanism contains the submechanisms for the primary reference fuels for diesel cetane ratings and submechanisms for the primary reference fuels for gasoline octane ratings, all in one integrated large kinetic reaction mechanism. Representative applications of this mechanism to two test problems are presented, one describing fuel/air autoignition variations with changes in fuel cetane numbers, and the other describing fuel combustion in a jet-stirred reactor environment with the fuel varying from pure 2,2,4,4,6,8,8-heptamethyl nonane (Cetane number of 15) to pure n-hexadecane (Cetane number of 100). The final reaction mechanism for the primary reference fuels for diesel fuel and gasoline is available on the web.

  1. Experimental Investigation of Spark-Ignited Combustion with High-Octane Biofuels and EGR. 1. Engine Load Range and Downsize Downspeed Opportunity

    SciTech Connect (OSTI)

    Splitter, Derek A [ORNL] [ORNL; Szybist, James P [ORNL] [ORNL

    2013-01-01T23:59:59.000Z

    The present study experimentally investigates spark-ignited combustion with 87 AKI E0 gasoline in its neat form and in midlevel alcohol gasoline blends with 24% vol/vol isobutanol gasoline (IB24) and 30% vol/vol ethanol gasoline (E30). A single-cylinder research engine was used with an 11.85:1 compression ratio, hydraulically actuated valves, laboratory intake air, and was capable of external exhaust gas recirculation (EGR). Experiments were conducted with all fuels to full-load conditions with = 1, using both 0% and 15% external cooled EGR. Higher octane number biofuel blends exhibited increased stoichiometric torque capability at this compression ratio, where the unique properties of ethanol enabled a doubling of the stoichiometric torque capability with E30 as compared to 87 AKI, up to 20 bar IMEPg (indicated mean effective pressure gross) at = 1. EGR provided thermodynamic advantages and was a key enabler for increasing engine efficiency for all fuel types. However, with E30, EGR was less useful for knock mitigation than gasoline or IB24. Torque densities with E30 with 15% EGR at = 1 operation were similar or better than a modern EURO IV calibration turbo-diesel engine. The results of the present study suggest that it could be possible to implement a 40% downsize + downspeed configuration (1.2 L engine) into a representative midsize sedan. For example, for a midsize sedan at a 65 miles/h cruise, an estimated fuel consumption of 43.9 miles per gallon (MPG) (engine out 102 g-CO2/km) could be achieved with similar reserve power to a 2.0 L engine with 87AKI (38.6 MPG, engine out 135 g-CO2/km). Data suggest that, with midlevel alcohol gasoline blends, engine and vehicle optimization can offset the reduced fuel energy content of alcohol gasoline blends and likely reduce vehicle fuel consumption and tailpipe CO2 emissions.

  2. Equivalence Ratio-EGR Control of HCCI Engine Operation and the Potential for Transition to Spark-Ignited Operation

    SciTech Connect (OSTI)

    Martinez-Frias, J; Aceves, S M; Flowers, D L; Smith, J R; Dibble, R

    2001-07-31T23:59:59.000Z

    This research investigates a control system for HCCI engines, where equivalence ratio, fraction of EGR and intake pressure are adjusted as needed to obtain satisfactory combustion. HCCI engine operation is analyzed with a detailed chemical kinetics code, HCT (Hydrodynamics, Chemistry and Transport), that has been extensively modified for application to engines. HCT is linked to an optimizer that determines the operating conditions that result in maximum brake thermal efficiency, while meeting the peak cylinder pressure restriction. The results show the values of the operating conditions that yield optimum efficiency as a function of torque and rpm. The engine has high NO{sub x} emissions for high power operation, so the possibility of switching to stoichiometric operation for high torque conditions is considered. Stoichiometric operation would allow the use of a three-way catalyst to reduce NO{sub x} emissions to acceptable levels. Finally, the paper discusses the possibility of transitioning from HCCI operation to SI operation to achieve high power output.

  3. National Ignition Facility Project Completion and Control System Status

    SciTech Connect (OSTI)

    Van Arsdall, P J; Azevedo, S G; Beeler, R G; Bryant, R M; Carey, R W; Demaret, R D; Fisher, J M; Frazier, T M; Lagin, L J; Ludwigsen, A P; Marshall, C D; Mathisen, D G; Reed, R K

    2009-10-02T23:59:59.000Z

    The National Ignition Facility (NIF) is the world's largest and most energetic laser experimental system providing a scientific center to study inertial confinement fusion (ICF) and matter at extreme energy densities and pressures. Completed in 2009, NIF is a stadium-sized facility containing a 1.8-MJ, 500-TW 192-beam ultraviolet laser and target chamber. A cryogenic tritium target system and suite of optical, X-ray and nuclear diagnostics will support experiments in a strategy to achieve fusion ignition starting in 2010. Automatic control of NIF is performed by the large-scale Integrated Computer Control System (ICCS), which is implemented by 2 MSLOC of Java and Ada running on 1300 front-end processors and servers. The ICCS framework uses CORBA distribution for interoperation between heterogeneous languages and computers. Laser setup is guided by a physics model and shots are coordinated by data-driven distributed workflow engines. The NIF information system includes operational tools and a peta-scale repository for provisioning experimental results. This paper discusses results achieved and the effort now underway to conduct full-scale operations and prepare for ignition.

  4. The effects of cycle-to-cycle variations on nitric oxide (NO) emissions for a spark-ignition engine: Numerical results

    E-Print Network [OSTI]

    Villarroel, Milivoy

    2004-11-15T23:59:59.000Z

    . To carry out the proposed study, an engine simulation model was used. The simulation determines engine performance and NO emissions as functions of engine operating conditions, engine design parameters, and combustion parameters. An automotive, spark...

  5. National Ignition Facility Cryogenic Target Systems Interim Management Plan

    SciTech Connect (OSTI)

    Warner, B

    2002-04-25T23:59:59.000Z

    Restricted availability of funding has had an adverse impact, unforeseen at the time of the original decision to projectize the National Ignition Facility (NIF) Cryogenic Target Handling Systems (NCTS) Program, on the planning and initiation of these efforts. The purpose of this document is to provide an interim project management plan describing the organizational structure and management processes currently in place for NCTS. Preparation of a Program Execution Plan (PEP) for NCTS has been initiated, and a current draft is provided as Attachment 1 to this document. The National Ignition Facility is a multi-megajoule laser facility being constructed at Lawrence Livermore National Laboratory (LLNL) by the National Nuclear Security Administration (NNSA) in the Department of Energy (DOE). Its primary mission is to support the Stockpile Stewardship Program (SSP) by performing experiments studying weapons physics, including fusion ignition. NIF also supports the missions of weapons effects, inertial fusion energy, and basic science in high-energy-density physics. NIF will be operated by LLNL under contract to the University of California (UC) as a national user facility. NIF is a low-hazard, radiological facility, and its operation will meet all applicable federal, state, and local Environmental Safety & Health (ES&H) requirements. The NCTS Interim Management Plan provides a summary of primary design criteria and functional requirements, current organizational structure, tracking and reporting procedures, and current planning estimates of project scope, cost, and schedule. The NIF Director controls the NIF Cryogenic Target Systems Interim Management Plan. Overall scope content and execution schedules for the High Energy Density Physics Campaign (SSP Campaign 10) are currently undergoing rebaselining and will be brought into alignment with resources expected to be available throughout the NNSA Future Years National Security Plan (FYNSP). The revised schedule for delivering this system will be decided at the national level, based on experiment campaign requirement dates that will be derived through this process. The current milestone date for achieving indirect-drive ignition on the NIF is December 2010. Maintaining this milestone requires that the cryogenic systems be complete and available for fielding experiments early enough that the planned experimental campaigns leading up to ignition can be carried out. The capability of performing non-ignition cryogenic experiments is currently required by March 2006, when the NIF's first cluster of beams is operational. Plans for cryogenic and non-cryogenic experiments on the NIF are contained in NNSA's Campaign 10 Program Plans for Ignition (MTE 10.1) and High Energy Density Sciences (MTE 10.2). As described in this document, the NCTS Program Manager is responsible for managing NIF Cryogenic Target Systems development, engineering, and deployment. Through the NIF Director, the NCTS Program Manager will put in place an appropriate Program Execution Plan (draft attached) at a later time consistent with the maturing and funding these efforts. The PEP will describe management methods for carrying out these activities.

  6. National Ignition Facility Control and Information System Operational Tools

    SciTech Connect (OSTI)

    Marshall, C D; Beeler, R G; Bowers, G A; Carey, R W; Fisher, J M; Foxworthy, C B; Frazier, T M; Mathisen, D G; Lagin, L J; Rhodes, J J; Shaw, M J

    2009-10-08T23:59:59.000Z

    The National Ignition Facility (NIF) in Livermore, California, is the world's highest-energy laser fusion system and one of the premier large scale scientific projects in the United States. The system is designed to setup and fire a laser shot to a fusion ignition or high energy density target at rates up to a shot every 4 hours. NIF has 192 laser beams delivering up to 1.8 MJ of energy to a {approx}2 mm target that is planned to produce >100 billion atm of pressure and temperatures of >100 million degrees centigrade. NIF is housed in a ten-story building footprint the size of three football fields as shown in Fig. 1. Commissioning was recently completed and NIF will be formally dedicated at Lawrence Livermore National Laboratory on May 29, 2009. The control system has 60,000 hardware controls points and employs 2 million lines of control system code. The control room has highly automated equipment setup prior to firing laser system shots. This automation has a data driven implementation that is conducive to dynamic modification and optimization depending on the shot goals defined by the end user experimenters. NIF has extensive facility machine history and infrastructure maintenance workflow tools both under development and deployed. An extensive operational tools suite has been developed to support facility operations including experimental shot setup, machine readiness, machine health and safety, and machine history. The following paragraphs discuss the current state and future upgrades to these four categories of operational tools.

  7. Spark-protected ion-source control and monitoring system at 1. 5 MV

    SciTech Connect (OSTI)

    Bogaty, J.M.; Zolecki, R.

    1981-01-01T23:59:59.000Z

    The Heavy Ion Fusion Program at Argonne National Laboratory utilizes a 1.5-MV Xe ion preaccelerator. Reliable beam transport requires accurate measurements and precise control of various ion-source parameters. This paper discusses the use of a multiplexed fiberoptic data-transmission system and low-cost digital stepper motors for control functions. Techniques are discussed which allow TTL and CMOS semiconductor curcuits to survive the destructive sparks which can occur in the 1.5-MV preaccelerator.

  8. Systems reliability analysis for the national ignition facility

    SciTech Connect (OSTI)

    Majumdar, K.C.; Annese, C.E.; MacIntyre, A.T.; Sicherman, A.

    1996-06-12T23:59:59.000Z

    A Reliability, Availability and Maintainability (RAM) analysis was initiated for the National Ignition Facility (NIF). The NIF is an inertial confinement fusion research facility designed to achieve controlled thermonuclear reaction; the preferred site for the NIF is the Lawrence Livermore National Laboratory (LLNL). The NIF RAM analysis has three purposes: (1) to allocate top level reliability and availability goals for the systems, (2) to develop an operability model for optimum maintainability, and (3) to determine the achievability of the allocated goals of the RAM parameters for the NIF systems and the facility operation as a whole. An allocation model assigns the reliability and availability goals for front line and support systems by a top-down approach; reliability analysis uses a bottom-up approach to determine the system reliability and availability from component level to system level.

  9. The Neutron Imaging System Fielded at the National Ignition Facility

    SciTech Connect (OSTI)

    Merrill, F E; Buckles, R; Clark, D D; Danly, C R; Drury, O B; Dzenitis, J M; Fatherley, V E; Fittinghoff, D N; Gallegos, R; Grim, G P; Guler, N; Loomis, E N; Lutz, S; Malone, R M; Martinson, D D; Mares, D; Morley, D J; Morgan, G L; Oertel, J A; Tregillis, I L; Volegov, P L; Weiss, P B; Wilde, C H

    2012-08-01T23:59:59.000Z

    A neutron imaging diagnostic has recently been commissioned at the National Ignition Facility (NIF). This new system is an important diagnostic tool for inertial fusion studies at the NIF for measuring the size and shape of the burning DT plasma during the ignition stage of Inertial Confinement Fusion (ICF) implosions. The imaging technique utilizes a pinhole neutron aperture, placed between the neutron source and a neutron detector. The detection system measures the two dimensional distribution of neutrons passing through the pinhole. This diagnostic has been designed to collect two images at two times. The long flight path for this diagnostic, 28 m, results in a chromatic separation of the neutrons, allowing the independently timed images to measure the source distribution for two neutron energies. Typically the first image measures the distribution of the 14 MeV neutrons and the second image of the 6-12 MeV neutrons. The combination of these two images has provided data on the size and shape of the burning plasma within the compressed capsule, as well as a measure of the quantity and spatial distribution of the cold fuel surrounding this core.

  10. Target diagnostic system for the National Ignition Facility (NIF)

    SciTech Connect (OSTI)

    Leeper, R.J.; Chandler, G.A.; Cooper, G.W.; Derzon, M.S. [and others

    1996-07-01T23:59:59.000Z

    A review of recent progress on the design of a diagnostic system proposed for ignition target experiments on the National Ignition Facility (NIF) will be presented. This diagnostic package contains an extensive suite of optical, x-ray, gamma-ray, and neutron diagnostics that enable measurements of the performance of both direct and indirect driven NIF targets. The philosophy used in designing all of the diagnostics in the set has emphasized redundant and independent measurement of fundamental physical quantities relevant to the operation of the NIF target. A unique feature of these diagnostics is that they are being designed to be capable of operating, in the high radiation, EMP, and debris backgrounds expected on the NIF facility. The diagnostic system proposed can be categorized into three broad areas: laser characterization, hohlraum characterization, and capsule performance diagnostics. The operating principles of a representative instrument from each class of diagnostic employed in this package will be summarized and illustrated with data obtained in recent prototype diagnostic tests.

  11. Fuel effects in homogeneous charge compression ignition (HCCI) engines

    E-Print Network [OSTI]

    Angelos, John P. (John Phillip)

    2009-01-01T23:59:59.000Z

    Homogenous-charge, compression-ignition (HCCI) combustion is a new method of burning fuel in internal combustion (IC) engines. In an HCCI engine, the fuel and air are premixed prior to combustion, like in a spark-ignition ...

  12. CORONA DISCHARGE IGNITION FOR ADVANCED STATIONARY NATURAL GAS ENGINES

    SciTech Connect (OSTI)

    Dr. Paul D. Ronney

    2003-09-12T23:59:59.000Z

    An ignition source was constructed that is capable of producing a pulsed corona discharge for the purpose of igniting mixtures in a test chamber. This corona generator is adaptable for use as the ignition source for one cylinder on a test engine. The first tests were performed in a cylindrical shaped chamber to study the characteristics of the corona and analyze various electrode geometries. Next a test chamber was constructed that closely represented the dimensions of the combustion chamber of the test engine at USC. Combustion tests were performed in this chamber and various electrode diameters and geometries were tested. The data acquisition and control system hardware for the USC engine lab was updated with new equipment. New software was also developed to perform the engine control and data acquisition functions. Work is underway to design a corona electrode that will fit in the new test engine and be capable igniting the mixture in one cylinder at first and eventually in all four cylinders. A test engine was purchased for the project that has two spark plug ports per cylinder. With this configuration it will be possible to switch between corona ignition and conventional spark plug ignition without making any mechanical modifications.

  13. Nitrogen spark denoxer

    DOE Patents [OSTI]

    Ng, Henry K. (Naperville, IL); Novick, Vincent J. (Downers Grove, IL); Sekar, Ramanujam R. (Naperville, IL)

    1997-01-01T23:59:59.000Z

    A NO.sub.X control system for an internal combustion engine includes an oxygen enrichment device that produces oxygen and nitrogen enriched air. The nitrogen enriched air contains molecular nitrogen that is provided to a spark plug that is mounted in an exhaust outlet of an internal combustion engine. As the nitrogen enriched air is expelled at the spark gap of the spark plug, the nitrogen enriched air is exposed to a pulsating spark that is generated across the spark gap of the spark plug. The spark gap is elongated so that a sufficient amount of atomic nitrogen is produced and is injected into the exhaust of the internal combustion engine. The injection of the atomic nitrogen into the exhaust of the internal combustion engine causes the oxides of nitrogen to be reduced into nitrogen and oxygen such that the emissions from the engine will have acceptable levels of NO.sub.X. The oxygen enrichment device that produces both the oxygen and nitrogen enriched air can include a selectively permeable membrane.

  14. Final Scientific and Technical Report - Practical Fiber Delivered Laser Ignition Systems for Vehicles

    SciTech Connect (OSTI)

    Yalin, Azer [Seaforth, LLC

    2014-03-30T23:59:59.000Z

    Research has characterized advanced kagome fiber optics for their use in laser ignition systems. In comparison to past fibers used in laser ignition, these fibers have the important advantage of being relatively bend-insensitivity, so that they can be bent and coiled without degradation of output energy or beam quality. The results are very promising for practical systems. For pulse durations of ~12 ns, the fibers could deliver >~10 mJ pulses before damage onset. A study of pulse duration showed that by using longer pulse duration (~20 – 30 ns), it is possible to carry even higher pulse energy (by factor of ~2-3) which also provides future opportunities to implement longer duration sources. Beam quality measurements showed nearly single-mode output from the kagome fibers (i.e. M2 close to 1) which is the optimum possible value and, combined with their high pulse energy, shows the suitability of the fibers for laser ignition. Research has also demonstrated laser ignition of an engine including reliable (100%) ignition of a single-cylinder gasoline engine using the laser ignition system with bent and coiled kagome fiber. The COV of IMEP was <2% which is favorable for stable engine operation. These research results, along with the continued reduction in cost of laser sources, support our commercial development of practical laser ignition systems.

  15. System for time-discretized vacuum ultraviolet spectroscopy of spark breakdown in air

    SciTech Connect (OSTI)

    Ryberg, D.; Fierro, A.; Dickens, J.; Neuber, A. [Center for Pulsed Power and Power Electronics, Department of Electrical and Computer Engineering and Department of Physics, Texas Tech University, Lubbock, Texas 79409 (United States)

    2014-10-15T23:59:59.000Z

    A system for time-discretized spectroscopic measurements of the vacuum ultraviolet (VUV) emission from spark discharges in the 60-160 nm range has been developed for the study of early plasma-forming phenomena. The system induces a spark discharge in an environment close to atmospheric conditions created using a high speed puff value, but is otherwise kept at high vacuum to allow for the propagation of VUV light. Using a vertical slit placed 1.5 mm from the discharge the emission from a small cross section of the discharge is allowed to pass into the selection chamber consisting of a spherical grating, with 1200 grooves/mm, and an exit slit set to 100 ?m. Following the exit slit is a photomultiplier tube with a sodium salicylate scintillator that is used for the time discretized measurement of the VUV signal with a temporal resolution limit of 10 ns. Results from discharges studied in dry air, Nitrogen, SF{sub 6}, and Argon indicate the emission of light with wavelengths shorter than 120 nm where the photon energy begins to approach the regime of direct photoionization.

  16. SPINTHIR: An ignition model for gas turbines

    E-Print Network [OSTI]

    Neophytou, A; Mastorakos, E

    2012-08-28T23:59:59.000Z

    that the spark characteristics and location used in the experiments, developed over a number of years by trial-and-error methods, are indeed close to optimum. 1. Introduction Aircraft engines must satisfy high-altitude relight capability. Inexpensive models... and shape of the spark, for the same spark energy, that lead to the best ignition behaviour are explored. Firstly, we introduce the mathematical model and the combustor investigated. Then we present the results computed with the model. The paper concludes...

  17. National Ignition Facility system design requirements Laser System SDR002

    SciTech Connect (OSTI)

    Larson, D.W.; Bowers, J.M.; Bliss, E.S.; Karpenko, V.P.; English, E.

    1996-08-20T23:59:59.000Z

    This System Design Requirement document establishes the performance, design, development, and test requirements for the NIP Laser System. The Laser System generates and delivers high-power optical pulses to the target chamber, and is composed of all optical puke creating and transport elements from Puke Generation through Final Optics as well as the special equipment that supports, energizes and controls them. The Laser System consists of the following WBS elements: 1.3 Laser System 1.4 Beam Transport System 1.6 Optical Components 1.7 Laser Control 1.8.7 Final Optics.

  18. Laser ignition

    DOE Patents [OSTI]

    Early, James W. (Los Alamos, NM); Lester, Charles S. (San Juan Pueblo, NM)

    2002-01-01T23:59:59.000Z

    In the apparatus of the invention, a first excitation laser or other excitation light source capable of producing alternating beams of light having different wavelengths is used in tandem with one or more ignitor lasers to provide a compact, durable, engine deployable fuel ignition laser system. Reliable fuel ignition is provided over a wide range of fuel conditions by using the single remote excitation light source for pumping one or more small lasers located proximate to one or more fuel combustion zones with alternating wavelengths of light.

  19. Distributed ignition method and apparatus for a combustion engine

    DOE Patents [OSTI]

    Willi, Martin L.; Bailey, Brett M.; Fiveland, Scott B.; Gong, Weidong

    2006-03-07T23:59:59.000Z

    A method and apparatus for operating an internal combustion engine is provided. The method comprises the steps of introducing a primary fuel into a main combustion chamber of the engine, introducing a pilot fuel into the main combustion chamber of the engine, determining an operating load of the engine, determining a desired spark plug ignition timing based on the engine operating load, and igniting the primary fuel and pilot fuel with a spark plug at the desired spark plug ignition timing. The method is characterized in that the octane number of the pilot fuel is lower than the octane number of the primary fuel.

  20. The National Ignition Facility: The world's largest optical system

    SciTech Connect (OSTI)

    Stolz, C J

    2007-10-15T23:59:59.000Z

    The National Ignition Facility (NIF), a 192-beam fusion laser, is presently under construction at the Lawrence Livermore National Laboratory with an expected completion in 2008. The facility contains 7,456 meter-scale optics for amplification, beam steering, vacuum barriers, focusing, polarization rotation, and wavelength conversion. A multiphase program was put in place to increase the monthly optical manufacturing rate by up to 20x while simultaneously reducing cost by up to 3x through a sub-scale development, full-scale facilitization, and a pilot production phase. Currently 80% of the optics are complete with over 50% installed. In order to manufacture the high quality optics at desired manufacturing rate of over 100 precision optics per month, new more deterministic advanced fabrication technologies had to be employed over those used to manufacture previous fusion lasers.

  1. Spark Spread

    Gasoline and Diesel Fuel Update (EIA)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for On-Highway4,1,50022,3,,,,6,1,9,1,50022,3,,,,6,1,Decade Energy I I' a(STEO) Highlights ď‚·2008Deutsche Bank|P. WeyantSpark

  2. Load Expansion of Stoichiometric HCCI Using Spark Assist and Hydraulic Valve Actuation

    SciTech Connect (OSTI)

    Szybist, James P [ORNL; Nafziger, Eric J [ORNL

    2010-01-01T23:59:59.000Z

    A spark-assist homogeneous charge compression ignition (SA-HCCI) operating strategy is presented here that allows for stoichiometric combustion from 1000-3000 rpm, and at loads as high as 750 kPa net IMEP. A single cylinder gasoline engine equipped with direct fuel injection and fully variable hydraulic valve actuation (HVA) is used for this experimental study. The HVA system enables negative valve overlap (NVO) valve timing for hot internal EGR. Spark-assist stabilizes combustion over a wide range of engine speeds and loads, and allows for stoichiometric operation at all conditions. Characteristics of both spark-ignited combustion and HCCI are present, with combustion analysis showing a distinctive spark ignited phase of combustion, followed by a much more rapid HCCI combustion phase. At high load, the maximum pressure rise rate is controlled by a combination of spark timing and retarding the intake valve closing angle. The latter reduces the effective compression ratio, and therefore the compressive temperatures, allowing the high load limit of the operating range to be expanded. The SA-HCCI operating strategy exhibits improved thermal efficiency at most operating conditions, with fuel consumption improvements up to 9% realized at light engine loads. The SA-HCCI operating strategy presented here does not provide an efficiency advantage at all operating points compared to SI combustion; a decrease was observed at the highest speed and at loads above 500 kPa net IMEP. At light engine loads the majority of the heat release takes place during the HCCI phase of the heat release, and as such the NOx emissions are very low and are similar to levels observed in pure HCCI. At higher loads, a larger portion of the heat release takes place during the spark ignited phase of combustion, which produces NOx emissions that are much higher than is typically associated with HCCI, but still represent a decrease from conventional SI combustion. By limiting the fuel/air mixture to stoichiometric conditions, the higher NOx emissions do not represent an implementation barrier to this strategy because compatibility is maintained with very effective conventional 3-way catalysts.

  3. A HYDROGEN IGNITION MECHANISM FOR EXPLOSIONS IN NUCLEAR FACILITY PIPING SYSTEMS

    SciTech Connect (OSTI)

    Leishear, R.

    2013-03-28T23:59:59.000Z

    Hydrogen explosions may occur simultaneously with water hammer accidents in nuclear facilities, and a theoretical mechanism to relate water hammer to hydrogen deflagrations and explosions is presented herein. Hydrogen and oxygen generation due to the radiolysis of water is a recognized hazard in pipe systems used in the nuclear industry, where the accumulation of hydrogen and oxygen at high points in the pipe system is expected, and explosive conditions may occur. Pipe ruptures in nuclear reactor cooling systems were attributed to hydrogen explosions inside pipelines, i.e., Hamaoka, Nuclear Power Station in Japan, and Brunsbuettel in Germany. Prior to these accidents, an ignition source for hydrogen was not clearly demonstrated, but these accidents demonstrated that a mechanism was, in fact, available to initiate combustion and explosion. A new theory to identify an ignition source and explosion cause is presented here, and further research is recommended to fully understand this explosion mechanism.

  4. Laser ignition

    DOE Patents [OSTI]

    Early, James W. (Los Alamos, NM); Lester, Charles S. (San Juan Pueblo, NM)

    2003-01-01T23:59:59.000Z

    In the apparatus of the invention, a first excitation laser or other excitation light source is used in tandem with an ignitor laser to provide a compact, durable, engine deployable fuel ignition laser system. Reliable fuel ignition is provided over a wide range of fuel conditions by using a single remote excitation light source for one or more small lasers located proximate to one or more fuel combustion zones. In a third embodiment, alternating short and long pulses of light from the excitation light source are directed into the ignitor laser. Each of the embodiments of the invention can be multiplexed so as to provide laser light energy sequentially to more than one ignitor laser.

  5. On the nature of cylic dispersion in spark assisted HCCI combustion

    SciTech Connect (OSTI)

    Wagner, Robert M [ORNL; Edwards, Kevin Dean [ORNL; Daw, C Stuart [ORNL; Green Jr, Johney Boyd [ORNL; Bunting, Bruce G [ORNL

    2006-01-01T23:59:59.000Z

    We report experimental observations of cyclic combus-tion variability during the transition between propagating flame combustion and homogeneous charge compres-sion ignition (HCCI) in a single-cylinder, stoichiometri-cally fueled, spark-assisted gasoline engine. The level of internal EGR was controlled with variable valve actua-tion (VVA), and HCCI combustion was achieved at high levels of internal EGR using the VVA system. Spark-ignition was used for conventional combustion and was optionally available during HCCI. The transition region between purely propagating combustion and HCCI was mapped at multiple engine speeds and loads by incre-mentally adjusting the internal EGR level and capturing data for 2800 sequential cycles. These measurements revealed a complex sequence of high COV, cyclic com-bustion variations when operating between the propagat-ing flame and HCCI limits. We were able to experimen-tally demonstrate an increase in the zone of acceptable HCCI-like combustion by using the spark assist. A de-tailed analysis of the cyclic variations in the intermediate zone indicates that they are dominated by nonlinear, nonrandom processes. Comparisons with previous studies of lean-limit cyclic variations suggest that nonlin-ear EGR feedback is probably the major source of the observed variations for this engine. The predictable na-ture of this feedback suggests the possibility of develop-ing on-line diagnostics and proactive control algorithms for expanding stable HCCI operation and improving transitions between conventional and HCCI modes.

  6. Rotating arc spark plug

    DOE Patents [OSTI]

    Whealton, John H.; Tsai, Chin-Chi

    2003-05-27T23:59:59.000Z

    A spark plug device includes a structure for modification of an arc, the modification including arc rotation. The spark plug can be used in a combustion engine to reduce emissions and/or improve fuel economy. A method for operating a spark plug and a combustion engine having the spark plug device includes the step of modifying an arc, the modifying including rotating the arc.

  7. Compression ignition engine having fuel system for non-sooting combustion and method

    DOE Patents [OSTI]

    Bazyn, Timothy; Gehrke, Christopher

    2014-10-28T23:59:59.000Z

    A direct injection compression ignition internal combustion engine includes a fuel system having a nozzle extending into a cylinder of the engine and a plurality of spray orifices formed in the nozzle. Each of the spray orifices has an inner diameter dimension of about 0.09 mm or less, and define inter-orifice angles between adjacent spray orifice center axes of about 36.degree. or greater such that spray plumes of injected fuel from each of the spray orifices combust within the cylinder according to a non-sooting lifted flame and gas entrainment combustion pattern. Related methodology is also disclosed.

  8. IGNITION IMPROVEMENT OF LEAN NATURAL GAS MIXTURES

    SciTech Connect (OSTI)

    Jason M. Keith

    2005-02-01T23:59:59.000Z

    This report describes work performed during a thirty month project which involves the production of dimethyl ether (DME) on-site for use as an ignition-improving additive in a compression-ignition natural gas engine. A single cylinder spark ignition engine was converted to compression ignition operation. The engine was then fully instrumented with a cylinder pressure transducer, crank shaft position sensor, airflow meter, natural gas mass flow sensor, and an exhaust temperature sensor. Finally, the engine was interfaced with a control system for pilot injection of DME. The engine testing is currently in progress. In addition, a one-pass process to form DME from natural gas was simulated with chemical processing software. Natural gas is reformed to synthesis gas (a mixture of hydrogen and carbon monoxide), converted into methanol, and finally to DME in three steps. Of additional benefit to the internal combustion engine, the offgas from the pilot process can be mixed with the main natural gas charge and is expected to improve engine performance. Furthermore, a one-pass pilot facility was constructed to produce 3.7 liters/hour (0.98 gallons/hour) DME from methanol in order to characterize the effluent DME solution and determine suitability for engine use. Successful production of DME led to an economic estimate of completing a full natural gas-to-DME pilot process. Additional experimental work in constructing a synthesis gas to methanol reactor is in progress. The overall recommendation from this work is that natural gas to DME is not a suitable pathway to improved natural gas engine performance. The major reasons are difficulties in handling DME for pilot injection and the large capital costs associated with DME production from natural gas.

  9. Development of an engine fuel and spark controller

    E-Print Network [OSTI]

    Suter, William Gregory

    1999-01-01T23:59:59.000Z

    The objective of this research was to develop an engine control unit (ECU) for a four cylinder engine to be used in a Formula SAE racers. The ECU must provide effective fuel injection and spark ignition control and provide for easy adjustment...

  10. Analysis of cyclic variability in spark-assisted HCCI combustion using a double Wiebe function

    SciTech Connect (OSTI)

    Wagner, Robert M [ORNL; Glewen, William J [ORNL; Edwards, Kevin Dean [ORNL; Daw, C Stuart [ORNL

    2008-01-01T23:59:59.000Z

    A heuristic algorithm based on a double Wiebe function is proposed for estimating the relative importance of distinct combustion modes (propagating flame and compression ignition) occurring within individual combustion cycles as an engine is transitioned from conventional spark-ignited (SI) combustion to homogeneous charge compression ignition (HCCI). The proposed algorithm automates the analysis and categorization of pressure measurements from large numbers of individual cycles, providing new insight into the unstable combustion processes occurring during mode transition. Similar techniques could potentially be utilized for on-line diagnostics and control of the balance between SI and HCCI combustion in spark-assisted HCCI.

  11. High Efficiency GDI Engine Research, with Emphasis on Ignition...

    Broader source: Energy.gov (indexed) [DOE]

    High Efficiency GDI Engine Research, with Emphasis on Ignition Systems High Efficiency GDI Engine Research, with Emphasis on Ignition Systems 2013 DOE Hydrogen and Fuel Cells...

  12. Spark-safe low-voltage detonator

    DOE Patents [OSTI]

    Lieberman, Morton L. (Albuquerque, NM)

    1989-01-01T23:59:59.000Z

    A column of explosive in a low-voltage detonator which makes it spark-safe ncludes an organic secondary explosive charge of HMX in the form of a thin pad disposed in a bore of a housing of the detonator in an ignition region of the explosive column and adjacent to an electrical ignition device at one end of the bore. The pad of secondary charge has an axial thickness within the range of twenty to thirty percent of its diameter. The explosive column also includes a first explosive charge of CP disposed in the housing bore in the ignition region of the explosive column next to the secondary charge pad on a side opposite from the ignition device. The first CP charge is loaded under sufficient pressure, 25 to 40 kpsi, to provide mechanical confinement of the pad of secondary charge and physical coupling thereof with the ignition device. The explosive column further includes a second explosive charge of CP disposed in the housing bore in a transition region of the explosive column next to the first CP charge on a side opposite from the pad of secondary charge. The second CP charge is loaded under sufficient pressure, about 10 kpsi, to allow occurrence of DDT. The first explosive CP charge has an axial thickness within the range of twenty to thirty percent of its diameter, whereas the second explosive CP charge contains a series of increments (nominally 4) each of which has an axial thickness-to-diameter ratio of one to two.

  13. Equilibrium ignition for ICF capsules

    SciTech Connect (OSTI)

    Lackner, K.S.; Colgate, S.A.; Johnson, N.L.; Kirkpatrick, R.C.; Menikoff, R.; Petschek, A.G.

    1993-12-31T23:59:59.000Z

    There are two fundamentally different approaches to igniting DT fuel in an ICF capsule which can be described as equilibrium and hot spot ignition. In both cases, a capsule which can be thought of as a pusher containing the DT fuel is imploded until the fuel reaches ignition conditions. In comparing high-gain ICF targets using cryogenic DT for a pusher with equilibrium ignition targets using high-Z pushers which contain the radiation. The authors point to the intrinsic advantages of the latter. Equilibrium or volume ignition sacrifices high gain for lower losses, lower ignition temperature, lower implosion velocity and lower sensitivity of the more robust capsule to small fluctuations and asymmetries in the drive system. The reduction in gain is about a factor of 2.5, which is small enough to make the more robust equilibrium ignition an attractive alternative.

  14. Plasma jet ignition device

    DOE Patents [OSTI]

    McIlwain, Michael E. (Franklin, MA); Grant, Jonathan F. (Wayland, MA); Golenko, Zsolt (North Reading, MA); Wittstein, Alan D. (Fairfield, CT)

    1985-01-15T23:59:59.000Z

    An ignition device of the plasma jet type is disclosed. The device has a cylindrical cavity formed in insulating material with an electrode at one end. The other end of the cylindrical cavity is closed by a metal plate with a small orifice in the center which plate serves as a second electrode. An arc jumping between the first electrode and the orifice plate causes the formation of a highly-ionized plasma in the cavity which is ejected through the orifice into the engine cylinder area to ignite the main fuel mixture. Two improvements are disclosed to enhance the operation of the device and the length of the plasma plume. One improvement is a metal hydride ring which is inserted in the cavity next to the first electrode. During operation, the high temperature in the cavity and the highly excited nature of the plasma breaks down the metal hydride, liberating hydrogen which acts as an additional fuel to help plasma formation. A second improvement consists of a cavity insert containing a plurality of spaced, metal rings. The rings act as secondary spark gap electrodes reducing the voltage needed to maintain the initial arc in the cavity.

  15. Improvement of extraction system geometry with suppression of possible Penning discharge ignition

    SciTech Connect (OSTI)

    Delferričre, O., E-mail: olivier.delferriere@cea.fr; Gobin, R.; Harrault, F.; Nyckees, S.; Tuske, O. [Commissariat ŕ l’Energie Atomique et aux Energies Alternatives, CEA/Saclay, DSM/IRFU, 91191-Gif/Yvette (France)] [Commissariat ŕ l’Energie Atomique et aux Energies Alternatives, CEA/Saclay, DSM/IRFU, 91191-Gif/Yvette (France)

    2014-02-15T23:59:59.000Z

    During the past two years, a new ECR 2.45 GHz type ion source has been developed especially dedicated to intense light ion injector project like IPHI (Injecteur Proton Haute Intensité), IFMIF (International Fusion Materials Irradiation Facility), to reduce beam emittance at RFQ entrance by shortening the length of the LEBT. This new ALISES concept (Advanced Light Ion Source Extraction System) is based on the use of an additional LEBT short length solenoid very close to the extraction aperture. The fringe field of this new solenoid produces the needed magnetic field to create the ECR resonance in the plasma chamber. Such geometry allows first putting the solenoid at ground potential, while saving space in front of the extraction to move the first LEBT solenoid closer and focus earlier the intense extracted beam. During the commissioning of the source in 2011–2012, ALISES has produced about 20 mA extracted from a 6 mm diameter plasma extraction hole at 23 kV. But the magnetic configuration combined to the new extraction system geometry led to important Penning discharge conditions in the accelerator column. Lots of them have been eliminated by inserting glass pieces between electrodes to modify equipotential lines with unfavorable ExB vacuum zones where particles were produced and trapped. To study Penning discharge location, several 3D calculations have been performed with OPERA-3D/TOSCA code to simulate the possible production and trapping of electrons in the extraction system. The results obtained on different sources already built have shown very good agreement with sparks location observed experimentally on electrodes. The simulations results as well as experimental measurements are presented and solutions to prevent possible Penning discharge in future source geometries are established.

  16. Peter Sparks Ninety Eight

    E-Print Network [OSTI]

    Robertson, Stephen

    Peter Sparks Ninety Eight A Ural ice-blast flattens Suffolk reed No gloves, coat flapping, creeping, the Girton Poetry Group website, at http://poetry.girton.cam.ac.uk #12;

  17. Peter Sparks Compass Reading

    E-Print Network [OSTI]

    Robertson, Stephen

    Peter Sparks Compass Reading You could I never love. Built of a bulk beyond my comprehension compass with its swinging fleur-de-lys watched by the crystal prism's sharp-cut eye? It represented

  18. EFFECT OF FUEL TYPE ON FLAME IGNITION BY TRANSIENT PLASMA Jianbang Liu1,2

    E-Print Network [OSTI]

    ABSTRACT Rise and delay times of mixtures of methane, propane, n-butane, iso-butane and iso- octane mixed performance of various fuels including methane, propane, iso-butane, n-butane and iso-octane mixed with air with air ignited by transient plasma discharge were investigated and compared with spark discharge ignition

  19. Prerequisites: Control Systems I+II, System Modeling, Engine Class (Introduction to Modeling and Control of

    E-Print Network [OSTI]

    Daraio, Chiara

    and Control The gas-diesel engine is a natural gas engine, where the combustion is initiated by a small is much higher than the ignition energy of a common spark plug. As a consequence, the natural gas and Control of Internal Combustion Engine Systems, IC Engines, ...), Matlab/Simulink experience Contact

  20. Spark-safe low-voltage detonator

    DOE Patents [OSTI]

    Lieberman, M.L.

    1988-07-01T23:59:59.000Z

    A column of explosive in a low-voltage detonator which makes it spark-safe includes an organic secondary explosive charge of HMX in the form of a thin pad disposed in a bore of a housing of the detonator in an ignition region of the explosive column and adjacent to an electrical ignition device at one end of the bore. The pad of secondary charge has an axial thickness within the range of twenty to thirty percent of its diameter. The explosive column also includes a first explosive charge of CP disposed in the housing bore in the ignition region of the explosive column next to the secondary charge pad on a side opposite from the ignition device. The first CP charge is loaded under sufficient pressure, 25 to 40 kpsi, to provide mechanical confinement of the pad of secondary charge and physical coupling thereof with the ignition device. The explosive column further includes a second explosive charge of CP disposed in the housing bore in a transition region of the explosive column next to the first CP charge on a side opposite from the pad of secondary charge. The second CP charge is loaded under sufficient pressure, about 10 kpsi, to allow occurrence of DDT. The first explosive CP charge has an axial thickness within the range of twenty to thirty percent of its diameter, whereas the second explosive CP charge contains a series of increments (nominally 4), each of which has an axial thickness-to-diameter ratio of one to two. 2 figs.

  1. MODELING CYCLIC VARIABILITY IN SPARK-ASSISTED HCCI

    SciTech Connect (OSTI)

    Daw, C Stuart [ORNL; Wagner, Robert M [ORNL; Edwards, Kevin Dean [ORNL; Green Jr, Johney Boyd [ORNL

    2008-01-01T23:59:59.000Z

    Spark assist appears to offer considerable potential for increasing the speed and load range over which homogeneous charge compression ignition (HCCI) is possible in gasoline engines. Numerous experimental studies of the transition between conventional spark-ignited (SI) propagating-flame combustion and HCCI combustion in gasoline engines with spark assist have demonstrated a high degree of deterministic coupling between successive combustion events. Analysis of this coupling suggests that the transition between SI and HCCI can be described as a sequence of bifurcations in a low-dimensional dynamic map. In this paper we describe methods for utilizing the deterministic relationship between cycles to extract global kinetic rate parameters that can be used to discriminate multiple distinct combustion states and develop a more quantitative understanding of the SI-HCCI transition. We demonstrate the application of these methods for indolene-containing fuels and point out an apparent HCCI mode switching not previously reported. Our results have specific implications for developing dynamic combustion models and feedback control strategies that utilize spark-assist to expand the operating range of HCCI combustion.

  2. Understanding the dynamics of spark-assisted HCCI combustion

    SciTech Connect (OSTI)

    Edwards, Kevin Dean [ORNL; Daw, C Stuart [ORNL; Wagner, Robert M [ORNL; Green Jr, Johney Boyd [ORNL; Glewen, William J [ORNL

    2007-01-01T23:59:59.000Z

    Spark assist appears to offer considerable potential for increasing the speed and load range over which homogeneous charge compression ignition (HCCI) is possible in gasoline engines. Numerous experimental studies of the transition between conventional spark-ignited (SI) propagating-flame combustion and HCCI combustion in gasoline engines with spark assist have demonstrated a high degree of deterministic coupling between successive combustion events. Analysis of this coupling suggests that the transition between SI and HCCI can be described as a sequence of bifurcations in a low-dimensional dynamic map. In this paper we describe methods for utilizing the deterministic relationship between cycles to extract global kinetic rate parameters that can be used to discriminate multiple distinct combustion states and develop a more quantitative understanding of the SI-HCCI transition. We demonstrate the application of these methods for indolene-containing fuels and point out an apparent HCCI mode switching not previously reported. Our results have specific implications for developing dynamic combustion models and feedback control strategies that utilize spark-assist to expand the operating range of HCCI combustion.

  3. Modeling Cyclic Variability in Spark-Assisted HCCI

    SciTech Connect (OSTI)

    Daw, C Stuart [ORNL; Edwards, Kevin Dean [ORNL; Wagner, Robert M [ORNL; Green Jr, Johney Boyd [ORNL

    2008-01-01T23:59:59.000Z

    Spark assist appears to offer considerable potential for increasing the speed and load range over which homogeneous charge compression ignition (HCCI) is possible in gasoline engines. Numerous experimental studies of the transition between conventional spark-ignited (SI) propagating-flame combustion and HCCI combustion in gasoline engines with spark assist have demonstrated a high degree of deterministic coupling between successive combustion events. Analysis of this coupling suggests that the transition between SI and HCCI can be described as a sequence of bifurcations in a low-dimensional dynamic map. In this paper, we describe methods for utilizing the deterministic relationship between cycles to extract global kinetic rate parameters that can be used to discriminate multiple distinct combustion states and develop a more quantitative understanding of the SI-HCCI transition. We demonstrate the application of these methods for indolene-containing fuels and point out an apparent HCCI mode switching not previously reported. Our results have specific implications for developing dynamic combustion models and feedback control strategies that utilize spark assist to expand the operating range of HCCI combustion.

  4. Supervision and control prototyping for an engine exhaust gas heat recovery system based on a steam Rankine cycle

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Supervision and control prototyping for an engine exhaust gas heat recovery system based on a steam of a practical supervi- sion and control system for a pilot Rankine steam process for exhaust gas heat recovery Rankine steam process for exhaust gas heat recovery from a spark-ignition (SI) engine, from a prototyping

  5. Using SPARK as a Solver for Modelica

    SciTech Connect (OSTI)

    Wetter, Michael; Wetter, Michael; Haves, Philip; Moshier, Michael A.; Sowell, Edward F.

    2008-06-30T23:59:59.000Z

    Modelica is an object-oriented acausal modeling language that is well positioned to become a de-facto standard for expressing models of complex physical systems. To simulate a model expressed in Modelica, it needs to be translated into executable code. For generating run-time efficient code, such a translation needs to employ algebraic formula manipulations. As the SPARK solver has been shown to be competitive for generating such code but currently cannot be used with the Modelica language, we report in this paper how SPARK's symbolic and numerical algorithms can be implemented in OpenModelica, an open-source implementation of a Modelica modeling and simulation environment. We also report benchmark results that show that for our air flow network simulation benchmark, the SPARK solver is competitive with Dymola, which is believed to provide the best solver for Modelica.

  6. A spark chamber for cosmic ray research

    E-Print Network [OSTI]

    Jelinek, Al Vincent

    1964-01-01T23:59:59.000Z

    are Elkonite 10W$ high-conductivity hard tungsten-copper alloy. They were chosen for the spark gap because they resist surface erosion in heavy electrical discharges. Six 20-KV, 500-picofarad "door knob capacitors" form the discharge capacitor bank. Figure... formed by the incident particle in each gap (typically 60 ion pairs) are sufficient to initiate a spark. This critical value + of the clearing is 45-5volts for the Geiger detection system and a pure argon gas filling. D. The Time Delay The total time...

  7. The Effects of Fuel Characteristics on Stoichiometric Spark-Assisted HCCI

    SciTech Connect (OSTI)

    Weall, Adam J [ORNL; Szybist, James P [ORNL

    2012-01-01T23:59:59.000Z

    The characteristics of fuel lean HCCI operation using a variety of fuels are well known and have been demonstrated using different engine concepts in the past. In contrast, stoichiometric operation of HCCI is less well documented. Recent studies have highlighted the benefits of operating at a stoichiometric condition in terms of load expansion combined with the applicability of three way catalyst technology to reduce NOx emissions. In this study the characterization of stoichiometric HCCI using gasoline-like fuels was undertaken. The fuels investigated are gasoline, a 50 vol% blend of iso-butanol and gasoline (IB50), and an 85% vol blend of ethanol and gasoline (E85). A single cylinder engine operating with direct injection and spark assist combined with a fully variable hydraulic valve actuation system allowed a wide range of operating parameters to be studied. The resultant fuel properties which differed in terms of octane rating, fuel oxygenation and heat of vaporization show that stoichiometric HCCI is possible using a range of fuels but that these fuel characteristics do have some effect on the combustion characteristics. How these fuel properties can enable an increased engine operating envelope to be achieved, in comparison with both fuel lean HCCI and conventional spark ignited combustion, is then discussed.

  8. Crevice volume effect on spark ignition engine efficiency

    E-Print Network [OSTI]

    Smith, Patrick M. (Patrick Michael)

    2013-01-01T23:59:59.000Z

    A set of experiments and a simulation study are completed to quantify the effect of the piston crevice on engine efficiency. The simulation study breaks down the loss mechanisms on brake efficiency at different displacement ...

  9. Turbocharged Spark Ignited Direct Injection - A Fuel Economy...

    Broader source: Energy.gov (indexed) [DOE]

    Cold-Start Performance and Emissions Behavior of Alcohol Fuels in an SIDI Engine Using Transient Hardware-In-Loop Test Meth BMW Diesel - Engine Concepts for Efficient Dynamics...

  10. Special Feature: Energy - The Spark that Ignited DOE Supercomputing

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the Department of Energy's (DOE's) first unclassified supercomputer center-the Controlled Thermonuclear Research Computer Center (CTRCC), established in 1974 at the Lawrence...

  11. Turbocharged Spark Ignited Direct Injection ? A Fuel Economy...

    Broader source: Energy.gov (indexed) [DOE]

    8 DEER Conference, August 5 th 2009 Showing The Potential Of Turbocharged SIDI AVL- Turbo SIDI Demonstrator GDI-Turbo Concept Car for low Fuel Consumption 5.0 5.5 6.0 6.5 7.0...

  12. Advanced Lean-Burn DI Spark Ignition Fuels Research

    Broader source: Energy.gov [DOE]

    2013 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting

  13. Turbocharged Spark Ignited Direct Injection - A Fuel Economy Solution for

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn'tOriginEducationVideoStrategic|IndustrialCenterMarch 4; RSVP byof Energy Turbines in

  14. Improving the Efficiency of Spark Ignited, Stoichiometric Natural Gas

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport(Fact Sheet),EnergyImprovement of the Lost FoamCoolingdesign,

  15. Special Feature: Energy - The Spark that Ignited DOE Supercomputing

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del Sol HomeFacebookScholarship Fund3Biology|SolarSpeakers Bureau SpeakersEnergy - The

  16. The Effects of Fuel Characteristics on Stoichiometric Spark-Assisted HCCI

    SciTech Connect (OSTI)

    Weall, Adam J [ORNL] [ORNL; Szybist, James P [ORNL] [ORNL

    2011-01-01T23:59:59.000Z

    The characteristics of fuel lean HCCI operation using a variety of fuels are well known and have been demonstrated using different engine concepts in the past. In contrast, stoichiometric operation of HCCI is less well documented. Recent studies have highlighted the benefits of operating at a stoichiometric condition in terms of load expansion combined with the applicability of three way catalyst technology to reduce NOx emissions. In this study the characterization of stoichiometric HCCI using gasoline-like fuels was undertaken. The fuels investigated are gasoline, a 50 vol% blend of iso-butanol and gasoline (IB50), and an 85% vol blend of ethanol and gasoline (E85). A single cylinder engine operating with direct injection and spark assist combined with a fully variable hydraulic valve actuation system allowed a wide range of operating parameters to be studied. This included the effects of negative valve overlap duration, intake valve closing and valve lift. Furthermore, the interaction between fuel injection timing and spark and how they can affect the required valve timing to achieve stoichiometric HCCI combustion are also studied. A comprehensive combustion and emissions analysis is conducted using gasoline, IB50 and E85 at an engine speed of 2000rpm over a range of operating loads. The resultant fuel properties which differed in terms of octane rating, fuel oxygenation and heat of vaporization show that stoichiometric HCCI is possible using a range of fuels but that these fuel characteristics do have some effect on the combustion characteristics. How these fuel properties can enable an increased engine operating envelope to be achieved, in comparison with both fuel lean HCCI and conventional spark ignited combustion, is then discussed.

  17. Multi-spot ignition in type Ia supernova models

    E-Print Network [OSTI]

    Roepke, F K; Niemeyer, J C; Woosley, S E

    2005-01-01T23:59:59.000Z

    We present a systematic survey of the capabilities of type Ia supernova explosion models starting from a number of flame seeds distributed around the center of the white dwarf star. To this end we greatly improved the resolution of the numerical simulations in the initial stages. This novel numerical approach facilitates a detailed study of multi-spot ignition scenarios with up to hundreds of ignition sparks. Two-dimensional simulations are shown to be inappropriate to study the effects of initial flame configurations. Based on a set of three-dimensional models, we conclude that multi-spot ignition scenarios may improve type Ia supernova models towards better agreement with observations. The achievable effect reaches a maximum at a limited number of flame ignition kernels as shown by the numerical models and corroborated by a simple dimensional analysis.

  18. Multi-spot ignition in type Ia supernova models

    E-Print Network [OSTI]

    F. K. Roepke; W. Hillebrandt; J. C. Niemeyer; S. E. Woosley

    2005-10-17T23:59:59.000Z

    We present a systematic survey of the capabilities of type Ia supernova explosion models starting from a number of flame seeds distributed around the center of the white dwarf star. To this end we greatly improved the resolution of the numerical simulations in the initial stages. This novel numerical approach facilitates a detailed study of multi-spot ignition scenarios with up to hundreds of ignition sparks. Two-dimensional simulations are shown to be inappropriate to study the effects of initial flame configurations. Based on a set of three-dimensional models, we conclude that multi-spot ignition scenarios may improve type Ia supernova models towards better agreement with observations. The achievable effect reaches a maximum at a limited number of flame ignition kernels as shown by the numerical models and corroborated by a simple dimensional analysis.

  19. Looking From A Hilltop: Automotive Propulsion System Technology...

    Broader source: Energy.gov (indexed) [DOE]

    Valve Lift, Active Fuel Management Spark Ignition Direct Injection Downsized SIDI Turbo Boosting Advanced Combustion 6 DOWNSIZED TURBO GASOLINE ENGINE Diesel Particulate...

  20. Laser ignition

    DOE Patents [OSTI]

    Early, James W.; Lester, Charles S.

    2004-01-13T23:59:59.000Z

    Sequenced pulses of light from an excitation laser with at least two resonator cavities with separate output couplers are directed through a light modulator and a first polarzing analyzer. A portion of the light not rejected by the first polarizing analyzer is transported through a first optical fiber into a first ignitor laser rod in an ignitor laser. Another portion of the light is rejected by the first polarizing analyzer and directed through a halfwave plate into a second polarization analyzer. A first portion of the output of the second polarization analyzer passes through the second polarization analyzer to a second, oscillator, laser rod in the ignitor laser. A second portion of the output of the second polarization analyzer is redirected by the second polarization analyzer to a second optical fiber which delays the beam before the beam is combined with output of the first ignitor laser rod. Output of the second laser rod in the ignitor laser is directed into the first ignitor laser rod which was energized by light passing through the first polarizing analyzer. Combined output of the first ignitor laser rod and output of the second optical fiber is focused into a combustible fuel where the first short duration, high peak power pulse from the ignitor laser ignites the fuel and the second long duration, low peak power pulse directly from the excitation laser sustains the combustion.

  1. Integral magnetic ignition pickup trigger

    SciTech Connect (OSTI)

    King, R.

    1992-10-27T23:59:59.000Z

    This patent describes a trigger system for the ignition system of an internal combustion engine having a crankcase with a rotatable crankshaft therein, and a flywheel on one end of the crankcase connected to an end of the crankshaft. It comprises: a nonferromagnetic disk-shaped hub for connection to the crankshaft and rotatable therewith on the end opposite the flywheel; and a stationary sensor mounted adjacent the hub for detecting impulses from the magnetically responsive elements as the hub rotates and utilizing the impulses to trigger the ignition system.

  2. Thermonuclear Ignition of Dark Galaxies

    E-Print Network [OSTI]

    J. Marvin Herndon

    2006-01-01T23:59:59.000Z

    thermonuclear ignition of stars by nuclear fission, and the corollary, non-ignition of stars. The possibility of

  3. Laser preheat enhanced ignition

    DOE Patents [OSTI]

    Early, James W. (Los Alamos, NM)

    1999-01-01T23:59:59.000Z

    A method for enhancing fuel ignition performance by preheating the fuel with laser light at a wavelength that is absorbable by the fuel prior to ignition with a second laser is provided.

  4. IGNITION AND FRONTIER SCIENCE ON THE NATIONAL IGNITION FACILITY

    SciTech Connect (OSTI)

    Moses, E

    2009-06-22T23:59:59.000Z

    The National Ignition Facility (NIF), the world's largest and most powerful laser system for inertial confinement fusion (ICF) and experiments studying high-energy-density (HED) science, is now operational at Lawrence Livermore National Laboratory (LLNL). The NIF construction Project was certified by the Department of Energy as complete on March 30, 2009. NIF, a 192-beam Nd-glass laser facility, will produce 1.8 MJ, 500 TW of light at the third-harmonic, ultraviolet light of 351 nm. On March 10, 2009, a total 192-beam energy of 1.1 MJ was demonstrated; this is approximately 30 times more energy than ever produced in an ICF laser system. The principal goal of NIF is to achieve ignition of a deuterium-tritium (DT) fuel capsule and provide access to HED physics regimes needed for experiments related to national security, fusion energy and for broader frontier scientific exploration. NIF experiments in support of indirect drive ignition will begin in FY2009. These first experiments represent the next phase of the National Ignition Campaign (NIC). The NIC is a 1.7 billion dollar national effort to achieve fusion ignition and is coordinated through a detailed execution plan that includes the science, technology, and equipment. Equipment required for ignition experiments include diagnostics, cryogenic target manipulator, and user optics. Participants in this effort include LLNL, General Atomics (GA), Los Alamos National Laboratory (LANL), Sandia National Laboratory (SNL), and the University of Rochester Laboratory for Energetics (LLE). The primary goal for NIC is to have all of the equipment operational and integrated into the facility and be ready to begin a credible ignition campaign in 2010. With NIF now operational, the long-sought goal of achieving self-sustained nuclear fusion and energy gain in the laboratory is much closer to realization. Successful demonstration of ignition and net energy gain on NIF will be a major step towards demonstrating the feasibility of Inertial Fusion Energy (IFE) and will likely focus the world's attention on the possibility of an ICF energy option. NIF experiments to demonstrate ignition and gain will use central-hot-spot (CHS) ignition, where a spherical fuel capsule is simultaneously compressed and ignited. The scientific basis for CHS has been intensively developed and has high probability of success. Achieving ignition with CHS will open the door for other advanced concepts, such as the use of high-yield pulses of visible wavelength rather than ultraviolet and Fast Ignition concepts. Moreover, NIF will have important scientific applications in such diverse fields as astrophysics, nuclear physics and materials science. The NIC will develop the full set of capabilities required to operate NIF as a major national and international user facility. A solicitation for NIF frontier science experiments to be conducted by the academic community is planned for summer 2009. This paper summarizes the design, performance, and status of NIF, experimental plans for NIC, and will present a brief discussion of the unparalleled opportunities to explore frontier basic science that will be available on the NIF.

  5. The Absence of Plasma in "Spark Plasma Sintering"

    E-Print Network [OSTI]

    Hulbert, Dustin M.

    2008-01-01T23:59:59.000Z

    investigations on the spark plasma sintering/synthesisinvestigations on the spark plasma sintering/synthesisenhancement in spark-plasma sintering: Impact of high

  6. Tailored net-shape powder composites by spark plasma sintering

    E-Print Network [OSTI]

    Khaleghi, Evan Aryan

    2012-01-01T23:59:59.000Z

    produced by spark plasma sintering”, Powder Metall. , 51, 59nanoparticles in spark plasma sintering. Mater. Sci. Eng. ,Evolution During Spark Plasma Sintering,” Ceram. Int. , 35,

  7. Tantalum-Tungsten Oxide Thermite Composite Prepared by Sol-Gel Synthesis and Spark Plasma Sintering

    SciTech Connect (OSTI)

    Cervantes, O; Kuntz, J; Gash, A; Munir, Z

    2009-02-13T23:59:59.000Z

    Energetic composite powders consisting of sol-gel derived nanostructured tungsten oxide were produced with various amounts of micrometer-scale tantalum fuel metal. Such energetic composite powders were ignition tested and results show that the powders are not sensitive to friction, spark and/or impact ignition. Initial consolidation experiments, using the High Pressure Spark Plasma Sintering (HPSPS) technique, on the sol-gel derived nanostructured tungsten oxide produced samples with higher relative density than can be achieved with commercially available tungsten oxide. The sol-gel derived nanostructured tungsten oxide with immobilized tantalum fuel metal (Ta - WO{sub 3}) energetic composite was consolidated to a density of 9.17 g.cm{sup -3} or 93% relative density. In addition those parts were consolidated without significant pre-reaction of the constituents, thus the sample retained its stored chemical energy.

  8. Maintenance FUSION IGNITION RESEARCH EXPERIMENT

    E-Print Network [OSTI]

    Insulation Enclosure Remote Maintenance Module FUSION IGNITION RESEARCH EXPERIMENT SYSTEM coils. The magnets are liquid nitrogen cooled and the entire device is surrounded by a thermal enclosure. The double wall vacuum vessel integrates cooling and shielding in a shape that maximizes shielding of ex

  9. Spark gap with low breakdown voltage jitter

    DOE Patents [OSTI]

    Rohwein, Gerald J. (Albuquerque, NM); Roose, Lars D. (Albuquerque, NM)

    1996-01-01T23:59:59.000Z

    Novel spark gap devices and electrodes are disclosed. The novel spark gap devices and electrodes are suitable for use in a variety of spark gap device applications. The shape of the electrodes gives rise to local field enhancements and reduces breakdown voltage jitter. Breakdown voltage jitter of approximately 5% has been measured in spark gaps according the invention. Novel electrode geometries and materials are disclosed.

  10. Spark gap with low breakdown voltage jitter

    DOE Patents [OSTI]

    Rohwein, G.J.; Roose, L.D.

    1996-04-23T23:59:59.000Z

    Novel spark gap devices and electrodes are disclosed. The novel spark gap devices and electrodes are suitable for use in a variety of spark gap device applications. The shape of the electrodes gives rise to local field enhancements and reduces breakdown voltage jitter. Breakdown voltage jitter of approximately 5% has been measured in spark gaps according the invention. Novel electrode geometries and materials are disclosed. 13 figs.

  11. Analysis of Homogeneous Charge Compression Ignition (HCCI) Engines for Cogeneration Applications

    SciTech Connect (OSTI)

    Aceves, S; Martinez-Frias, J; Reistad, G

    2004-04-30T23:59:59.000Z

    This paper presents an evaluation of the applicability of Homogeneous Charge Compression Ignition Engines (HCCI) for small-scale cogeneration (less than 1 MWe) in comparison to five previously analyzed prime movers. The five comparator prime movers include stoichiometric spark-ignited (SI) engines, lean burn SI engines, diesel engines, microturbines and fuel cells. The investigated option, HCCI engines, is a relatively new type of engine that has some fundamental differences with respect to other prime movers. Here, the prime movers are compared by calculating electric and heating efficiency, fuel consumption, nitrogen oxide (NOx) emissions and capital and fuel cost. Two cases are analyzed. In Case 1, the cogeneration facility requires combined power and heating. In Case 2, the requirement is for power and chilling. The results show that the HCCI engines closely approach the very high fuel utilization efficiency of diesel engines without the high emissions of NOx and the expensive diesel fuel. HCCI engines offer a new alternative for cogeneration that provides a unique combination of low cost, high efficiency, low emissions and flexibility in operating temperatures that can be optimally tuned for cogeneration systems. HCCI engines are the most efficient technology that meets the oncoming 2007 CARB NOx standards for cogeneration engines. The HCCI engine appears to be a good option for cogeneration systems and merits more detailed analysis and experimental demonstration.

  12. High Efficiency GDI Engine Research, with Emphasis on Ignition...

    Broader source: Energy.gov (indexed) [DOE]

    confidential, or otherwise restricted information Overview High Efficiency GDI Engine Research with Emphasis on Ignition Systems 2 Timeline Project start: Sept. 2012...

  13. Low profile thermite igniter

    DOE Patents [OSTI]

    Halcomb, Danny L. (Camden, OH); Mohler, Jonathan H. (Spring Valley, OH)

    1991-03-05T23:59:59.000Z

    A thermite igniter/heat source comprising a housing, high-density thermite, and low-density thermite. The housing has a relatively low profile and can focus energy by means of a torch-like ejection of hot reaction products and is externally ignitable.

  14. Thermal Issues Associated with the Lighting Systems, Electronics Racks, and Pre-Amplifier Modules in the National Ignition System

    SciTech Connect (OSTI)

    A. C. Owen; J. D. Bernardin; K. L. Lam

    1998-08-01T23:59:59.000Z

    This report summarizes an investigation of the thermal issues related to the National Ignition Facility. The influence of heat sources such as lighting fixtures, electronics racks, and pre-amplifier modules (PAMs) on the operational performance of the laser guide beam tubes and optical alignment hardware in the NE laser bays were investigated with experiments and numerical models. In particular, empirical heat transfer data was used to establish representative and meaningful boundary conditions and also serve as bench marks for computational fluid dynamics (CFD) models. Numerical models, constructed with a commercial CFD code, were developed to investigate the extent of thermal plumes and radiation heat transfer from the heat sources. From these studies, several design modifications were recommended including reducing the size of all fluorescent lights in the NIF laser bays to single 32 W bulb fixtures, maintaining minimum separation distances between light fixtures/electronics racks and beam transport hardware, adding motion sensors in areas of the laser bay to control light fixture operation during maintenance procedures, properly cooling all electronics racks with air-water heat exchangers with heat losses greater than 25 W/rack to the M1 laser bay, ensuring that the electronics racks are not overcooked and thus maintain their surface temperatures to within a few degrees centigrade of the mean air temperature, and insulating the electronic bays and optical support structures on the PAMs.

  15. CHEVROLET | ELECTRIC | GREEN | SPARK EV | TECHNOLOGY. INNOVATION...

    Open Energy Info (EERE)

    CHEVROLET | ELECTRIC | GREEN | SPARK EV | TECHNOLOGY. INNOVATION & SOLUTIONS | GREENER VEHICLES Home There are currently no posts in this category. Syndicate content...

  16. Using indium tin oxide material to implement the imaging of microwave plasma ignition process

    SciTech Connect (OSTI)

    Wang, Qiang; Hou, Lingyun; Zhang, Guixin, E-mail: guixin@mail.tsinghua.edu.cn; Zhang, Boya; Liu, Cheng [Department of Electrical Engineering, Tsinghua University, Beijing 100084 (China); Wang, Zhi; Huang, Jian [State Key Laboratory of Automotive Safety and Energy, Tsinghua University, Beijing 100084 (China)

    2014-02-17T23:59:59.000Z

    In this paper, a method is introduced to get global observation of microwave plasma ignition process at high pressure. A microwave resonator was designed with an indium tin oxide coated glass at bottom. Microwave plasma ignition was implemented in methane and air mixture at 10 bars by a 2?ms-3?kW-2.45?GHz microwave pulse, and the high speed images of the ignition process were obtained. The images visually proved that microwave plasma ignition could lead to a multi-point ignition. The system may also be applied to obtain Schlieren images, which is commonly used to observe the development of flame kernel in an ignition process.

  17. Mechanical Behavior of Cryomilled Ni Superalloy by Spark Plasma Sintering

    E-Print Network [OSTI]

    2009-01-01T23:59:59.000Z

    Ni Superalloy by Spark Plasma Sintering Z. ZHANG, B.Q. HAN,cryomilling and spark plasma sintering (SPS) was studied.prepared by the spark plasma sintering (SPS) technique. To

  18. Semiconductor bridge, SCB, ignition of energetic materials

    SciTech Connect (OSTI)

    Bickes, R.W.; Grubelich, M.D.; Harris, S.M.; Merson, J.A.; Tarbell, W.W.

    1997-04-01T23:59:59.000Z

    Sandia National Laboratories` semiconductor bridge, SCB, is now being used for the ignition or initiation of a wide variety of exeoergic materials. Applications of this new technology arose because of a need at the system level to provide light weight, small volume and low energy explosive assemblies. Conventional bridgewire devices could not meet the stringent size, weight and energy requirements of our customers. We present an overview of SCB technology and the ignition characteristics for a number of energetic materials including primary and secondary explosives, pyrotechnics, thermites and intermetallics. We provide examples of systems designed to meet the modern requirements that sophisticated systems must satisfy in today`s market environments.

  19. Combustion, Efficiency, and Fuel Effects in a Spark-Assisted...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Combustion, Efficiency, and Fuel Effects in a Spark-Assisted HCCI Gasoline Engine Combustion, Efficiency, and Fuel Effects in a Spark-Assisted HCCI Gasoline Engine 2004 Diesel...

  20. Load Expansion of Stoichiometric HCCI Using Spark Assist and...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    of Stoichiometric HCCI Using Spark Assist and Hydraulic Valve Actuation Load Expansion of Stoichiometric HCCI Using Spark Assist and Hydraulic Valve Actuation Presentation given at...

  1. Scientists ignite aluminum water mix

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Scientists ignite aluminum water mix Scientists ignite aluminum water mix Don't worry, that beer can you're holding is not going to spontaneously burst into flames. June 30, 2014...

  2. Review of the National Ignition Campaign 2009-2012

    SciTech Connect (OSTI)

    Lindl, John; Landen, Otto; Edwards, John; Moses, Ed [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)] [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Collaboration: NIC Team

    2014-02-15T23:59:59.000Z

    The National Ignition Campaign (NIC) was a multi-institution effort established under the National Nuclear Security Administration of DOE in 2005, prior to the completion of the National Ignition Facility (NIF) in 2009. The scope of the NIC was the planning and preparation for and the execution of the first 3 yr of ignition experiments (through the end of September 2012) as well as the development, fielding, qualification, and integration of the wide range of capabilities required for ignition. Besides the operation and optimization of the use of NIF, these capabilities included over 50 optical, x-ray, and nuclear diagnostic systems, target fabrication facilities, experimental platforms, and a wide range of NIF facility infrastructure. The goal of ignition experiments on the NIF is to achieve, for the first time, ignition and thermonuclear burn in the laboratory via inertial confinement fusion and to develop a platform for ignition and high energy density applications on the NIF. The goal of the NIC was to develop and integrate all of the capabilities required for a precision ignition campaign and, if possible, to demonstrate ignition and gain by the end of FY12. The goal of achieving ignition can be divided into three main challenges. The first challenge is defining specifications for the target, laser, and diagnostics with the understanding that not all ignition physics is fully understood and not all material properties are known. The second challenge is designing experiments to systematically remove these uncertainties. The third challenge is translating these experimental results into metrics designed to determine how well the experimental implosions have performed relative to expectations and requirements and to advance those metrics toward the conditions required for ignition. This paper summarizes the approach taken to address these challenges, along with the progress achieved to date and the challenges that remain. At project completion in 2009, NIF lacked almost all the diagnostics and infrastructure required for ignition experiments. About half of the 3 yr period covered in this review was taken up by the effort required to install and performance qualify the equipment and experimental platforms needed for ignition experiments. Ignition on the NIF is a grand challenge undertaking and the results presented here represent a snapshot in time on the path toward that goal. The path forward presented at the end of this review summarizes plans for the Ignition Campaign on the NIF, which were adopted at the end of 2012, as well as some of the key results obtained since the end of the NIC.

  3. On thermonuclear ignition criterion at the National Ignition Facility

    SciTech Connect (OSTI)

    Cheng, Baolian; Kwan, Thomas J. T.; Wang, Yi-Ming; Batha, Steven H. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2014-10-15T23:59:59.000Z

    Sustained thermonuclear fusion at the National Ignition Facility remains elusive. Although recent experiments approached or exceeded the anticipated ignition thresholds, the nuclear performance of the laser-driven capsules was well below predictions in terms of energy and neutron production. Such discrepancies between expectations and reality motivate a reassessment of the physics of ignition. We have developed a predictive analytical model from fundamental physics principles. Based on the model, we obtained a general thermonuclear ignition criterion in terms of the areal density and temperature of the hot fuel. This newly derived ignition threshold and its alternative forms explicitly show the minimum requirements of the hot fuel pressure, mass, areal density, and burn fraction for achieving ignition. Comparison of our criterion with existing theories, simulations, and the experimental data shows that our ignition threshold is more stringent than those in the existing literature and that our results are consistent with the experiments.

  4. Experimental Component Characterization, Monte-Carlo-Based Image Generation and Source Reconstruction for the Neutron Imaging System of the National Ignition Facility

    SciTech Connect (OSTI)

    Barrera, C A; Moran, M J

    2007-08-21T23:59:59.000Z

    The Neutron Imaging System (NIS) is one of seven ignition target diagnostics under development for the National Ignition Facility. The NIS is required to record hot-spot (13-15 MeV) and downscattered (6-10 MeV) images with a resolution of 10 microns and a signal-to-noise ratio (SNR) of 10 at the 20% contour. The NIS is a valuable diagnostic since the downscattered neutrons reveal the spatial distribution of the cold fuel during an ignition attempt, providing important information in the case of a failed implosion. The present study explores the parameter space of several line-of-sight (LOS) configurations that could serve as the basis for the final design. Six commercially available organic scintillators were experimentally characterized for their light emission decay profile and neutron sensitivity. The samples showed a long lived decay component that makes direct recording of a downscattered image impossible. The two best candidates for the NIS detector material are: EJ232 (BC422) plastic fibers or capillaries filled with EJ399B. A Monte Carlo-based end-to-end model of the NIS was developed to study the imaging capabilities of several LOS configurations and verify that the recovered sources meet the design requirements. The model includes accurate neutron source distributions, aperture geometries (square pinhole, triangular wedge, mini-penumbral, annular and penumbral), their point spread functions, and a pixelated scintillator detector. The modeling results show that a useful downscattered image can be obtained by recording the primary peak and the downscattered images, and then subtracting a decayed version of the former from the latter. The difference images need to be deconvolved in order to obtain accurate source distributions. The images are processed using a frequency-space modified-regularization algorithm and low-pass filtering. The resolution and SNR of these sources are quantified by using two surrogate sources. The simulations show that all LOS configurations have a resolution of 7 microns or better. The 28 m LOS with a 7 x 7 array of 100-micron mini-penumbral apertures or 50-micron square pinholes meets the design requirements and is a very good design alternative.

  5. Self-ignition of S.I. engine model fuels: A shock tube investigation at high pressure

    SciTech Connect (OSTI)

    Fieweger, K.; Blumenthal, R.; Adomeit, G. [RWTH, Aachen (Germany). Inst. fuer Allegemeine Mechanik] [RWTH, Aachen (Germany). Inst. fuer Allegemeine Mechanik

    1997-06-01T23:59:59.000Z

    The self-ignition of several spark-ignition (SI) engine fuels (iso-octane, methanol, methyl tert-butyl ether and three different mixtures of iso-octane and n-heptane), mixed with air, was investigated experimentally under relevant engine conditions by the shock tube technique. Typical modes of the self-ignition process were registered cinematographically. For temperatures relevant to piston engine combustion, the self-ignition process always starts as an inhomogeneous, deflagrative mild ignition. This instant is defined by the ignition delay time, {tau}{sub defl}. The deflagration process in most cases is followed by a secondary explosion (DDT). This transition defines a second ignition delay time, {tau}{sub DDT}, which is a suitable approximation for the chemical ignition delay time, if the change of the thermodynamic conditions of the unburned test gas due to deflagration is taken into account. For iso-octane at p = 40 bar, a NTC (negative temperature coefficient), behavior connected with a two step (cool flame) self-ignition at low temperatures was observed. This process was very pronounced for rich and less pronounced for stoichiometric mixtures. The results of the {tau}{sub DDT} delays of the stoichiometric mixtures were shortened by the primary deflagration process in the temperature range between 800 and 1,000 K. Various mixtures of iso-octane and n-heptane were investigated. The results show a strong influence of the n-heptane fraction in the mixture, both on the ignition delay time and on the mode of self-ignition. The self-ignition of methanol and MTBE (methyl tert-butyl ether) is characterized by a very pronounced initial deflagration. For temperatures below 900 K (methanol: 800 K), no secondary explosion occurs. Taking into account the pressure increase due to deflagration, the measured delays {tau}{sub DDT} of the secondary explosion are shortened by up to one order of magnitude.

  6. Using SPARK as a Solver for Modelica

    E-Print Network [OSTI]

    Wetter, Michael

    2008-01-01T23:59:59.000Z

    and Simulation with Modelica 2.1. John Wiley & Sons.Vadim Engelson. 1998. “Modelica – A Uni?ed Object-OrientedSPARK AS A SOLVER FOR MODELICA Michael Wetter 1 , Philip

  7. Characterisation of Mechanically Alloyed Ti-Al-B Nanocomposite Consolidated by Spark Plasma Sintering

    E-Print Network [OSTI]

    Han, Young Hwan

    2003-01-01T23:59:59.000Z

    consolidated by spark plasma sintering H. B. Lee, S. H. Kim,consolidated by spark plasma sintering of mechanicallyfollowed by SPS (spark plasma sintering) is well suited for

  8. High Efficiency GDI Engine Research, with Emphasis on Ignition...

    Broader source: Energy.gov (indexed) [DOE]

    Funding in FY13: 400k Funding in FY14: 350k Overview High Efficiency GDI Engine Research with Emphasis on Ignition Systems 2 Timeline Project start: FY 2013 ...

  9. Ignition sequence of an annular multi-injector combustor

    E-Print Network [OSTI]

    Philip, Maxime; Vicquelin, Ronan; Schmitt, Thomas; Durox, Daniel; Bourgoin, Jean-François; Candel, Sébastien

    2013-01-01T23:59:59.000Z

    Ignition is a critical process in combustion systems. In aeronautical combustors, altitude relight capacities are required in case of accidental extinction of the chamber. A simultaneous study of light-round ignition in an annular multi-injector combustor has been performed on the experimental and numerical sides. This effort allows a unique comparison to assess the reliability of Large-Eddy Simulation (LES) in such a configuration. Results are presented in fluid dynamics videos.

  10. A spark chamber for cosmic ray research 

    E-Print Network [OSTI]

    Jelinek, Al Vincent

    1964-01-01T23:59:59.000Z

    chambez *re r- -e evenis, anc to obtain good sta- s s ical data with the prese. . i sysiezz wou'8 require t! e exarina- iion o" severs' '. '. ous" no. pictures. ne effic ency zoz two simu ianeous particles in argon oius alcohol vspour is e timasec.... to be 75I15~ji. The effic ency of the . con-he' ium and the helium-alcohol vapour zillings are 1 igner about 85- 5(i. 3. Spurious Sparking Spurious sparks in the chamber can be attributed to a num- ber of factors. The most probable cause is ions left...

  11. Giant coercivity of dense nanostructured spark plasma sintered barium hexaferrite

    E-Print Network [OSTI]

    Giant coercivity of dense nanostructured spark plasma sintered barium hexaferrite F. Mazaleyrat and dense material together. In this paper, it is shown that the spark plasma sintering method (SPS) is able, Spark Plasma Sintering (SPS) allows to produce nonos- tructured Ba-ferrite with a density close to 90

  12. Transforming the Museum SPARK | THINK | MAKE

    E-Print Network [OSTI]

    Aalberts, Daniel P.

    Transforming the Museum SPARK | THINK | MAKE #12;WILLIAMS COLLEGE MUSEUM OF ART 1 Museums. Because of its varied collections and its breadth and nimbleness of forms, the college museum of the museum's 9th decade of history. As we developed the vision for its future we sought to both leverage its

  13. Ignition of Aluminum Particles and Clouds

    SciTech Connect (OSTI)

    Kuhl, A L; Boiko, V M

    2010-04-07T23:59:59.000Z

    Here we review experimental data and models of the ignition of aluminum (Al) particles and clouds in explosion fields. The review considers: (i) ignition temperatures measured for single Al particles in torch experiments; (ii) thermal explosion models of the ignition of single Al particles; and (iii) the unsteady ignition Al particles clouds in reflected shock environments. These are used to develop an empirical ignition model appropriate for numerical simulations of Al particle combustion in shock dispersed fuel explosions.

  14. Conceptual Design - Polar Drive Ignition Campaign

    SciTech Connect (OSTI)

    Hansen, R

    2012-04-05T23:59:59.000Z

    The Laboratory for Laser Energetics (LLE) at the University of Rochester is proposing a collaborative effort with Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratories (LANL), the Naval Research Laboratory (NRL), and General Atomics (GA) with the goal of developing a cryogenic polar drive (PD) ignition platform on the National Ignition Facility (NIF). The scope of this proposed project requires close discourse among theorists, experimentalists, and laser and system engineers. This document describes how this proposed project can be broken into a series of parallel independent activities that, if implemented, could deliver this goal in the 2017 timeframe. This Conceptual Design document is arranged into two sections: mission need and design requirements. Design requirements are divided into four subsystems: (1) A point design that details the necessary target specifications and laser pulse requirements; (2) The beam smoothing subsystem that describes the MultiFM 1D smoothing by spectral dispersion (SSD); (3) New optical elements that include continuous phase plates (CPP's) and distributed polarization rotators (DPR's); and (4) The cryogenic target handling and insertion subsystem, which includes the design, fabrication, testing, and deployment of a dedicated PD ignition target insertion cryostat (PD-ITIC). This document includes appendices covering: the primary criteria and functional requirements, the system design requirements, the work breakdown structure, the target point design, the experimental implementation plan, the theoretical unknowns and technical implementation risks, the estimated cost and schedule, the development plan for the DPR's, the development plan for MultiFM 1D SSD, and a list of acronym definitions. While work on the facility modifications required for PD ignition has been in progress for some time, some of the technical details required to define the specific modifications for a Conceptual Design Review (CDR) remain to be defined. In all cases, the facility modifications represent functional changes to existing systems or capabilities. The bulk of the scope yet to be identified is associated with the DPR's and MultiFM beam smoothing. Detailed development plans for these two subsystems are provided in Appendices H and I; additional discussion of subsystem requirements based on the physics of PD ignition is given in Section 3. Accordingly, LLE will work closely with LLNL to develop detailed conceptual designs for the PD-specific facility modifications, including assessments of the operational impact of implementation (e.g., changing optics for direct rather than indirect-drive illumination and swapping from a hohlraum-based ITIC to one that supports PD). Furthermore, the experimental implementation plan represents the current best understanding of the experimental campaigns required to achieve PD ignition. This plan will evolve based on the lessons learned from the National Ignition Campaign (NIC) and ongoing indirect-drive ignition experiments. The plan does not take the operational realities of the PD configuration into account; configuration planning for the proposed PD experiments is beyond the scope of this document.

  15. TOWARD A STANDARD IGNITION SOURCE

    E-Print Network [OSTI]

    Volkingburg, David R. Van

    2011-01-01T23:59:59.000Z

    and ignited with a small propane torch. The top center ofhead is supplied with propane. In these experiments allin the pre-mixed mode with propane alone to simulate trash

  16. Exceptions to ignition source controls

    SciTech Connect (OSTI)

    SCHLOSSER, R.L.

    2003-03-01T23:59:59.000Z

    This document provides a basis for acceptance of risks associated with equipment that does not fully comply with the ignition source control requirements as they will be applied by the Technical Safety Requirements prepared to implement the documented safety analysis.

  17. Ni SPECIATION IN A HUMIC ACID-KAOLINITE SYSTEM Maarten Nachtegaal,l Elham A. Ghabbour,2 Geoffrey Davies2and Donald L. Sparks}

    E-Print Network [OSTI]

    Sparks, Donald L.

    .e. clay minerals, oxides and SOM), very few studies have been conducted on metal sorption to clay mineral-oxide metals like Ni, Co or Zn on clay minerals and Al oxides under ambient soil conditions.2 These surface precipitates show a dramatic stabilization over time in the model systems studied and thus may lead

  18. National Ignition Campaign Hohlraum Energetics

    SciTech Connect (OSTI)

    Meezan, N B; Atherton, L J; Callahan, D A; Dewald, E L; Dixit, S N; Dzenitis, E G; Edwards, M J; Haynam, C A; Hinkel, D E; Jones, O S; Landen, O; London, R A; Michel, P A; Moody, J D; Milovich, J L; Schneider, M B; Thomas, C A; Town, R J; Warrick, A L; Weber, S V; Widmann, K; Glenzer, S H; Suter, L J; MacGowan, B J; Kline, J L; Kyrala, G A; Nikroo, A

    2009-11-16T23:59:59.000Z

    The first series of experiments on the National Ignition Facility (NIF) [E. I. Moses, R. N. Boyd, B. A. Remington, C. J. Keane, and R. Al-Ayat, 'The National Ignition Facility: ushering in a new age for high energy density science,' Phys. Plasmas 16, 041006 (2009)] tested ignition hohlraum 'energetics,' a term described by four broad goals: (1) Measurement of laser absorption by the hohlraum; (2) Measurement of the x-ray radiation flux (T{sub RAD}{sup 4}) on the surrogate ignition capsule; (3) Quantitative understanding of the laser absorption and resultant x-ray flux; and (4) Determining whether initial hohlraum performance is consistent with requirements for ignition. This paper summarizes the status of NIF hohlraum energetics experiments. The hohlraum targets and experimental design are described, as well as the results of the initial experiments. The data demonstrate low backscattered energy (< 10%) for hohlraums filled with helium gas. A discussion of our current understanding of NIF hohlraum x-ray drive follows, including an overview of the computational tools, i.e., radiation-hydrodynamics codes, that have been used to design the hohlraums. The performance of the codes is compared to x-ray drive and capsule implosion data from the first NIF experiments. These results bode well for future NIF ignition hohlraum experiments.

  19. Effects of different fuels on a turbocharged, direct injection, spark ignition engine

    E-Print Network [OSTI]

    Negrete, Justin E

    2010-01-01T23:59:59.000Z

    The following pages describe the experimentation and analysis of two different fuels in GM's high compression ratio, turbocharged direct injection (TDI) engine. The focus is on a burn rate analysis for the fuels - gasoline ...

  20. A user-friendly computer simulation of a spark ignition engine 

    E-Print Network [OSTI]

    Berrios, Ivan

    1993-01-01T23:59:59.000Z

    and not for six-cylinder and eight-cylinder engines. An attempt was made to find a comparable friction model in the literature developed for eight- cylinder engines, but no such model was found. Intake and Exhaust Valve Flow The intake and exhaust flows.... e. , Temperature = 76 F and Pressure = 29. 53a Hg [22]. Six different configurations were tested and they are described in Table 2. Table 2. Test Cases S ifications. 050 IN 050 EXH EXH LIFT Header B CR GM Cam P. SS 61995 Isk 256/262 GM Cam P...

  1. Knock limits in spark ignited direct injected engines using gasoline/ethanol blends

    E-Print Network [OSTI]

    Kasseris, Emmanuel P

    2011-01-01T23:59:59.000Z

    Direct Fuel Injection (DI) extends engine knock limits compared to Port Fuel Injection (PFI) by utilizing the in-cylinder charge cooling effect due to fuel evaporation. The use of gasoline/ethanol blends in DI is therefore ...

  2. Vehicle Technologies Office Merit Review 2014: Advanced Lean-Burn DI Spark Ignition Fuels Research

    Broader source: Energy.gov [DOE]

    Presentation given by Sandia National Laboratories at 2014 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about advanced lean...

  3. Piston ring pack design effects on production spark ignition engine oil consumption : a simulation analysis

    E-Print Network [OSTI]

    Senzer, Eric B

    2007-01-01T23:59:59.000Z

    One of the most significant contributors to an engine's total oil consumption is the piston ring-pack. As a result, optimization of the ring pack is becoming more important for engine manufacturers and lubricant suppliers. ...

  4. Vehicle Technologies Office Merit Review 2015: Advanced Lean-Burn DI Spark Ignition Fuels Research

    Broader source: Energy.gov [DOE]

    Presentation given by Sandia National Laboratory at 2015 DOE Hydrogen and Fuel Cells Program and vehicle technologies office annual merit review and peer evaluation meeting about advanced lean-burn...

  5. STUDIES OF WALL FLAME QUENCHING AND HYDROCARBON EMISSIONS IN A MODEL SPARK IGNITION ENGINE

    E-Print Network [OSTI]

    Ishikawa, Nobuhiko

    2011-01-01T23:59:59.000Z

    the Piston of an Internal Combustion Engine," In . J. Mech.Cylinder of an Internal Combustion Engine," SAE Paper No.Walls of an Internal Combustion Engine, Sixth Symposium (

  6. Alternate fuels for general-aviation aircraft with spark-ignition engines. Final report

    SciTech Connect (OSTI)

    Ferrara, A.M.

    1988-06-01T23:59:59.000Z

    This report describes the results of a study into the behavior of several alternate fuels that are under consideration for use in general aviation aircraft engines. The study consisted of a literature search and engine tests using a dynamometer. The literature search identified material compatibility problems and possible solutions to these problems. For the engine tests, a number of gasoline/alcohol blends were prepared using both ethanol and methanol in varying concentrations and the vapor-lock behavior was identified. Neat alcohols and methyl-tertiary-butyl ether were also used in the engine, and special operational conditions and problems were identified.

  7. Sources and characteristics of oil consumption in a spark-ignition engine

    E-Print Network [OSTI]

    Yilmaz, Ertan, 1970-

    2003-01-01T23:59:59.000Z

    (cont.) At low load, oil flowing past by the piston was found to be the major consumption source, while the contributions of oil evaporation and of blowby entrainment became more significant with increasing engine load. ...

  8. SYNCHRONIZATION OF COMBUSTION VARIATIONS IN A MULTI-CYLINDER SPARK IGNITION ENGINE

    E-Print Network [OSTI]

    Tennessee, University of

    and Engineering Science University of Tennessee Knoxville, TN 37996-2210 Francis T. Connolly Ford Motor Company may have significant implications for engine diagnostics and control. INTRODUCTION Fuel-lean operation of model is expected to be most useful for understanding general trends (e.g., for engine diag- nostics

  9. THE CONCEPT OF ISOCHORIC CENTRAL SPARK IGNITION AND ITS FUEL GAIN IN INERTIAL FUSION

    E-Print Network [OSTI]

    Boyer, Edmond

    of two distinct regions named as hot and cold regions and formed by hydro-dynamical implosion of fuel power plant has been investigated and fuel gain for isochoric model in this method is calculated. We have shown the effects of different physical parameters of inertial fusion on fuel gain and optimized

  10. Practical delay modeling of externally recirculated burned gas fraction for Spark-Ignited Engines

    E-Print Network [OSTI]

    . INTRODUCTION AND COMPARISON WITH DIESEL EXHAUST GAS RECIRCULATION To prevent the malicious knock phenomenon downsides. During tip-outs (defined as a transient mode during which the torque demand is suddenly decreased. Scheme of the intake burned gas fraction dynamics. In the seemingly similar context of automotive Diesel

  11. ORIGINS OF CYCLIC DISPERSION PATTERNS IN SPARK IGNITION ENGINES R. M. Wagner*

    E-Print Network [OSTI]

    Tennessee, University of

    dispersion is not a purely random process. * Corresponding author Proceedings of the 1998 Technical Meeting are stochastic or exhibit a combination of sto- chastic and linear deterministic behavior [1]. Observed results. Specifically, cycle-to-cycle combus- tion variations were characterized using bifurcation

  12. Advanced Lean-Burn DI Spark Ignition Fuels Research | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny: The Future of1 AAcceleratedDepartment of Energy LWR Nuclear Fuel2 DOE Hydrogen

  13. Advanced Lean-Burn DI Spark Ignition Fuels Research | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny: The Future of1 AAcceleratedDepartment of Energy LWR Nuclear Fuel2 DOE

  14. Advanced Lean-Burn DI Spark Ignition Fuels Research | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny: The Future of1 AAcceleratedDepartment of Energy LWR Nuclear Fuel2 DOE10 DOE

  15. Advanced Lean-Burn DI Spark Ignition Fuels Research | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny: The Future of1 AAcceleratedDepartment of Energy LWR Nuclear Fuel2 DOE10 DOE09

  16. The National Ignition Facility (NIF) A Path to Fusion Energy

    SciTech Connect (OSTI)

    Moses, E

    2006-11-27T23:59:59.000Z

    Fusion energy has long been considered a promising clean, nearly inexhaustible source of energy. Power production by fusion micro-explosions of inertial confinement fusion (ICF) targets has been a long term research goal since the invention of the first laser in 1960. The NIF is poised to take the next important step in the journey by beginning experiments researching ICF ignition. Ignition on NIF will be the culmination of over thirty years of ICF research on high-powered laser systems such as the Nova laser at LLNL and the OMEGA laser at the University of Rochester as well as smaller systems around the world. NIF is a 192 beam Nd-glass laser facility at LLNL that is more than 90% complete. The first cluster of 48 beams is operational in the laser bay, the second cluster is now being commissioned, and the beam path to the target chamber is being installed. The Project will be completed in 2009 and ignition experiments will start in 2010. When completed NIF will produce up to 1.8 MJ of 0.35 {micro}m light in highly shaped pulses required for ignition. It will have beam stability and control to higher precision than any other laser fusion facility. Experiments using one of the beams of NIF have demonstrated that NIF can meet its beam performance goals. The National Ignition Campaign (NIC) has been established to manage the ignition effort on NIF. NIC has all of the research and development required to execute the ignition plan and to develop NIF into a fully operational facility. NIF will explore the ignition space, including direct drive, 2{omega} ignition, and fast ignition, to optimize target efficiency for developing fusion as an energy source. In addition to efficient target performance, fusion energy requires significant advances in high repetition rate lasers and fusion reactor technology. The Mercury laser at LLNL is a high repetition rate Nd-glass laser for fusion energy driver development. Mercury uses state-o-the art technology such as ceramic laser slabs and light diode pumping for improved efficiency and thermal management. Progress in NIF, NIC, Mercury, and the path forward for fusion energy will be presented.

  17. Combustion in Homogeneous Charge Compression Ignition Engines: Experiments and Detailed Chemical Kinetic Simulations

    SciTech Connect (OSTI)

    Flowers, D L

    2002-06-07T23:59:59.000Z

    Homogeneous charge compression ignition (HCCI) engines are being considered as an alternative to diesel engines. The HCCI concept involves premixing fuel and air prior to induction into the cylinder (as is done in current spark-ignition engine) then igniting the fuel-air mixture through the compression process (as is done in current diesel engines). The combustion occurring in an HCCI engine is fundamentally different from a spark-ignition or Diesel engine in that the heat release occurs as a global autoignition process, as opposed to the turbulent flame propagation or mixing controlled combustion used in current engines. The advantage of this global autoignition is that the temperatures within the cylinder are uniformly low, yielding very low emissions of oxides of nitrogen (NO{sub x}, the chief precursors to photochemical smog). The inherent features of HCCI combustion allows for design of engines with efficiency comparable to, or potentially higher than, diesel engines. While HCCI engines have great potential, several technical barriers exist which currently prevent widespread commercialization of this technology. The most significant challenge is that the combustion timing cannot be controlled by typical in-cylinder means. Means of controlling combustion have been demonstrated, but a robust control methodology that is applicable to the entire range of operation has yet to be developed. This research focuses on understanding basic characteristics of controlling and operating HCCI engines. Experiments and detailed chemical kinetic simulations have been applied to the characterize some of the fundamental operational and design characteristics of HCCI engines. Experiments have been conducted on single and multi-cylinder engines to investigate general features of how combustion timing affects the performance and emissions of HCCI engines. Single-zone modeling has been used to characterize and compare the implementation of different control strategies. Multi-zone modeling has been applied to investigate combustion chamber design with respect to increasing efficiency and reducing emissions in HCCI engines.

  18. SPARK Version 1. 1 user manual

    SciTech Connect (OSTI)

    Weissenburger, D.W.

    1988-01-01T23:59:59.000Z

    This manual describes the input required to use Version 1.1 of the SPARK computer code. SPARK 1.1 is a library of FORTRAN main programs and subprograms designed to calculate eddy currents on conducting surfaces where current flow is assumed zero in the direction normal to the surface. Surfaces are modeled with triangular and/or quadrilateral elements. Lorentz forces produced by the interaction of eddy currents with background magnetic fields can be output at element nodes in a form compatible with most structural analysis codes. In addition, magnetic fields due to eddy currents can be determined at points off the surface. Version 1.1 features eddy current streamline plotting with optional hidden-surface-removal graphics and topological enhancements that allow essentially any orientable surface to be modeled. SPARK also has extensive symmetry specification options. In order to make the manual as self-contained as possible, six appendices are included that present summaries of the symmetry options, topological options, coil options and code algorithms, with input and output examples. An edition of SPARK 1.1 is available on the Cray computers at the National Magnetic Fusion Energy Computer Center at Livermore, California. Another more generic edition is operational on the VAX computers at the Princeton Plasma Physics Laboratory and is available on magnetic tape by request. The generic edition requires either the GKS or PLOT10 graphics package and the IMSL or NAG mathematical package. Requests from outside the United States will be subject to applicable federal regulations regarding dissemination of computer programs. 22 refs.

  19. Ryan Naraine, Eweek, 2004.11.11: "XP SP2 flaw warning sparks debate on

    E-Print Network [OSTI]

    Bernstein, Daniel

    system. "San Jose, Calif.-based Finjan Software released an alert warning that attackers could `silently warning is overblown. " `Our early analysis indicates that Finjan's claims are potentially misleadingRyan Naraine, Eweek, 2004.11.11: "XP SP2 flaw warning sparks debate on disclosure "The debate over

  20. SCB thermite igniter studies

    SciTech Connect (OSTI)

    Bickes, R.W. Jr.; Wackerbarth, D.E. [Sandia National Labs., Albuquerque, NM (United States); Mohler, J.H. [Energetic Materials Associates, Inc., Vero Beach, FL (United States)

    1996-12-31T23:59:59.000Z

    The authors report on recent studies comparing the ignition threshold of temperature cycled, SCB thermite devices with units that were not submitted to temperature cycling. Aluminum/copper-oxide thermite was pressed into units at two densities, 45% of theoretical maximum density (TMD) or 47% of TMD. Half of each of the density sets underwent three thermal cycles; each cycle consisted of 2 hours at 74 C and 2 hours at {minus}54 C, with a 5 minute maximum transfer time between temperatures. The temperature cycled units were brought to ambient temperature before the threshold testing. Both the density and the thermal cycling affected the all-fire voltage. Using a 5.34 {micro}F CDU (capacitor discharge unit) firing set, the all-fire voltage for the units that were not temperature cycled increased with density from 32.99 V (45% TMD) to 39.32 V (47% TMD). The all-fire voltages for the thermally cycled units were 34.42 V (45% TMD) and 58.1 V (47% TMD). They also report on no-fire levels at ambient temperature for two component designs; the 5 minute no-fire levels were greater than 1.2 A. Units were also subjected to tests in which 1 W of RF power was injected into the bridges at 10 MHz for 5 minutes. The units survived and fired normally afterwards. Finally, units were subjected to pin-to-pin electrostatic discharge (ESD) tests. None of the units fired upon application of the ESD pulse, and all of the tested units fired normally afterwards.

  1. Low Frequency Architecture for Multi-Lamp CCFL Systemswith Capacitive Ignition

    E-Print Network [OSTI]

    Low Frequency Architecture for Multi-Lamp CCFL Systemswith Capacitive Ignition Monm Doshi (I-0425 regan.zane@colorado.edu Absfruci-This paper presents a low frequency architecture for driving parallel to the architecture is a proposed capacitive coupling approach for ac lamp ignition. The system consists of a single

  2. Weapons Activities/ Inertial Confinement Fusion Ignition

    E-Print Network [OSTI]

    (SSP) through three strategic objectives: · Achieve thermonuclear ignition in the laboratory experiments to include access to thermonuclear burn conditions in the laboratory, a unique and unprecedented to demonstrate thermonuclear ignition in the laboratory. The NIF is a 192-bea

  3. IGNITE Leadership Fellows 2012--2013 Application

    E-Print Network [OSTI]

    Blanco, Philip R.

    IGNITE Leadership Fellows 2012--2013 Application Instructions: Please complete the form below in its entirety. Applicants for the IGNITE Leadership Fellows cohort are expected to participate fully, and be committed to their own personal and leadership development. Name

  4. Type B Accident Investigation, Subcontractor Employee Personal Protective Equipment Ignition Incident on February 18, 2003, at the East Tennessee Technology Park, Oak Ridge, Tennessee

    Broader source: Energy.gov [DOE]

    On February 18, 2003, a general laborer employed at the East Tennessee Technology Park (ETTP) by MACTEC Constructors, Inc. (MACTEC) was performing rebar removal with a gas-powered cut-off machine. MACTEC is a subcontractor to Bechtel Jacobs Company LL (BJC). The sparks from the cut-off machine ignited the right leg of his 100% cotton anticontamination (anti-c) coveralls and the plastic bootie.

  5. Thermonuclear Ignition of Dark Galaxies

    E-Print Network [OSTI]

    J. Marvin Herndon

    2006-04-13T23:59:59.000Z

    Dark matter is thought to be at least an order of magnitude more abundant than luminous matter in the Universe, but there has yet to be an unambiguous identification of a wholly dark, galactic-scale structure. There is, however, increasing evidence that VIRGOHI 21 may be a dark galaxy. If VIRGOHI 21 turns out to be composed of dark stars, having approximately the same mass of stars found in luminous galaxies, it will pose an enigma within the framework of current astrophysical models, but will provide strong support for my concept, published in 1994 in the Proceedings of the Royal Society of London, of the thermonuclear ignition of stars by nuclear fission, and the corollary, non-ignition of stars. The possibility of galactic thermonuclear ignition is discussed from that framework and leads to my suggestion that the distribution of luminous stars in a galaxy may simply be a reflection of the galactic distribution of the heavy elements.

  6. Method for reducing ignition delay of fuels

    SciTech Connect (OSTI)

    Hoppie, L.O.

    1984-05-15T23:59:59.000Z

    A method of reducing ignition delay /tau/, of fuels to negligible values and negligible differences is disclosed. Fuels conditioned to have such negligible values and differences are readily used in multiple fuel engines, such fuels self-ignite substantially instantaneously when injected into an oxidant, require substantially no heat transfer from the oxidant to effect the self-ignition, and the self-ignition is sufficient to sustain continued combustion.

  7. Combustion, Efficiency, and Fuel Effects in a Spark-Assisted...

    Broader source: Energy.gov (indexed) [DOE]

    COMBUSTION, EFFICIENCY, AND FUEL EFFECTS IN A SPARK- ASSISTED HCCI GASOLINE ENGINE Bruce G. Bunting Fuels, Engines, and Emissions Research Center Oak Ridge National Laboratory...

  8. Laser ablation based fuel ignition

    DOE Patents [OSTI]

    Early, James W. (Los Alamos, NM); Lester, Charles S. (San Juan Pueblo, NM)

    1998-01-01T23:59:59.000Z

    There is provided a method of fuel/oxidizer ignition comprising: (a) application of laser light to a material surface which is absorptive to the laser radiation; (b) heating of the material surface with the laser light to produce a high temperature ablation plume which emanates from the heated surface as an intensely hot cloud of vaporized surface material; and (c) contacting the fuel/oxidizer mixture with the hot ablation cloud at or near the surface of the material in order to heat the fuel to a temperature sufficient to initiate fuel ignition.

  9. Laser ablation based fuel ignition

    DOE Patents [OSTI]

    Early, J.W.; Lester, C.S.

    1998-06-23T23:59:59.000Z

    There is provided a method of fuel/oxidizer ignition comprising: (a) application of laser light to a material surface which is absorptive to the laser radiation; (b) heating of the material surface with the laser light to produce a high temperature ablation plume which emanates from the heated surface as an intensely hot cloud of vaporized surface material; and (c) contacting the fuel/oxidizer mixture with the hot ablation cloud at or near the surface of the material in order to heat the fuel to a temperature sufficient to initiate fuel ignition. 3 figs.

  10. Integral low-energy thermite igniter

    DOE Patents [OSTI]

    Gibson, A.; Haws, L.D.; Mohler, J.H.

    1983-05-13T23:59:59.000Z

    In a thermite igniter/heat source comprising a container holding an internal igniter load, there is provided the improvement wherein the container consists essentially of consumable consolidated thermite having a low gas output upon combustion, whereby upon ignition, substantially all of the container and said load is consumed with low gas production.

  11. Integral low-energy thermite igniter

    DOE Patents [OSTI]

    Gibson, Albert (Dayton, OH); Haws, Lowell D. (Springboro, OH); Mohler, Jonathan H. (Spring Valley, OH)

    1984-08-14T23:59:59.000Z

    In a thermite igniter/heat source comprising a container holding an internal igniter load, there is provided the improvement wherein the container consists essentially of consumable consolidated thermite having a low gas output upon combustion, whereby upon ignition, substantially all of the container and said load is consumed with low gas production.

  12. Cooldown of the Compact Ignition Tokamak

    SciTech Connect (OSTI)

    Keeton, D.C.

    1987-08-01T23:59:59.000Z

    Cooldown of the Compact Ignition Tokamak (CIT) with the baseline liquid nitrogen cooling system was analyzed. On the basis of this analysis and present knowledge of the two-phase heat transfer, the current baseline CIT can be cooled down in about 1.5 h. An extensive heat transfer test program is recommended to reduce uncertainty in the heat transfer performance and to explore methods for minimizing the cooldown time. An alternate CIT cooldown system is described which uses a pressurized gaseous helium coolant in a closed-loop system. It is shown analytically that this system will cool down the CIT well within 1 h. Confidence in this analysis is sufficiently high that a heat transfer test program would not be necessary. The added cost of this alternate system is estimated to be about $5.3 million. This helium cooling system represents a reasonable backup approach to liquid nitrogen cooling of the CIT. 3 refs., 12 figs., 3 tabs.

  13. EXCEPTIONS TO IGNITION SOURCE CONTROLS

    SciTech Connect (OSTI)

    SCHLOSSER, R.L.

    2003-09-25T23:59:59.000Z

    This document provides a basis for acceptance of risks associated with equipment and materials that do not fully comply with the ignition source controls as they are applied by the Technical Safety Requirements prepared to implement the controls required by the documented safety analysis for tank farms facilities.

  14. Green Spark Ventures LLC | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to: navigation, search OpenEI ReferenceJump to: navigation,II WindAirplaneGreenEnergySpark

  15. Spark Energy, LP | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere IRaghuraji Agro Industries Pvt LtdShawangunk,Southeast Colorado PowerSouthwesternCompanies | Open EnergySpark

  16. Spark Energy, LP (Connecticut) | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualProperty Edit with formSoutheastern IL Elec Coop, IncSouthwestern ElectricSpain:Fork,Spark

  17. Spark Energy, LP (Massachusetts) | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualProperty Edit with formSoutheastern IL Elec Coop, IncSouthwesternSpark Energy, LP

  18. Spark Energy, LP | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualProperty Edit with formSoutheastern IL Elec Coop, IncSouthwesternSpark Energy, LPSpark

  19. Ignition feedback regenerative free electron laser (FEL) amplifier

    DOE Patents [OSTI]

    Kim, Kwang-Je (Burr Ridge, IL); Zholents, Alexander (Walnut Creek, CA); Zolotorev, Max (Oakland, CA)

    2001-01-01T23:59:59.000Z

    An ignition feedback regenerative amplifier consists of an injector, a linear accelerator with energy recovery, and a high-gain free electron laser amplifier. A fraction of the free electron laser output is coupled to the input to operate the free electron laser in the regenerative mode. A mode filter in this loop prevents run away instability. Another fraction of the output, after suitable frequency up conversion, is used to drive the photocathode. An external laser is provided to start up both the amplifier and the injector, thus igniting the system.

  20. Stockpile Stewardship and the National Ignition Facility

    SciTech Connect (OSTI)

    Moses, E

    2012-01-04T23:59:59.000Z

    The National Ignition Facility (NIF), the world's most energetic laser system, is operational at Lawrence Livermore National Laboratory (LLNL). Since the completion of the construction project in March 2009, NIF has completed nearly 150 target experiments for the National Ignition Campaign (NIC), High Energy Density Stewardship Science (HEDSS) in the areas of radiation transport, material dynamics at high pressure in the solid state, as well as fundamental science and other national security missions. NIF capabilities and infrastructure are in place to support all of its missions with over 50 X-ray, optical and nuclear diagnostic systems and the ability to shoot cryogenic targets and DT layered capsules. NIF is now qualified for use of tritium and other special materials as well as to perform high yield experiments and classified experiments. DT implosions with record indirect-drive neutron yield of 4.5 x 10{sup 14} neutrons have been achieved. A series of 43 experiments were successfully executed over a 27-day period, demonstrating the ability to perform precise experiments in new regimes of interest to HEDSS. This talk will provide an update of the progress on the NIF capabilities, NIC accomplishments, as well as HEDSS and fundamental science experimental results and an update of the experimental plans for the coming year.

  1. The National Ignition Facility: The Path to Ignition, High Energy Density Science and Inertial Fusion Energy

    SciTech Connect (OSTI)

    Moses, E

    2011-03-25T23:59:59.000Z

    The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory (LLNL) in Livermore, CA, is a Nd:Glass laser facility capable of producing 1.8 MJ and 500 TW of ultraviolet light. This world's most energetic laser system is now operational with the goals of achieving thermonuclear burn in the laboratory and exploring the behavior of matter at extreme temperatures and energy densities. By concentrating the energy from its 192 extremely energetic laser beams into a mm{sup 3}-sized target, NIF can produce temperatures above 100 million K, densities of 1,000 g/cm{sup 3}, and pressures 100 billion times atmospheric pressure - conditions that have never been created in a laboratory and emulate those in the interiors of planetary and stellar environments. On September 29, 2010, NIF performed the first integrated ignition experiment which demonstrated the successful coordination of the laser, the cryogenic target system, the array of diagnostics and the infrastructure required for ignition. Many more experiments have been completed since. In light of this strong progress, the U.S. and the international communities are examining the implication of achieving ignition on NIF for inertial fusion energy (IFE). A laser-based IFE power plant will require a repetition rate of 10-20 Hz and a 10% electrical-optical efficiency laser, as well as further advances in large-scale target fabrication, target injection and tracking, and other supporting technologies. These capabilities could lead to a prototype IFE demonstration plant in 10- to 15-years. LLNL, in partnership with other institutions, is developing a Laser Inertial Fusion Energy (LIFE) baseline design and examining various technology choices for LIFE power plant This paper will describe the unprecedented experimental capabilities of the NIF, the results achieved so far on the path toward ignition, the start of fundamental science experiments and plans to transition NIF to an international user facility providing access to researchers around the world. The paper will conclude with a discussion of LIFE, its development path and potential to enable a carbon-free clean energy future.

  2. Piezoelectric Ignition of Nanocomposite Energetic Materials

    SciTech Connect (OSTI)

    Eric Collins; Michelle Pantoya; Andreas A. Neuber; Michael Daniels; Daniel Prentice

    2014-01-01T23:59:59.000Z

    Piezoelectric initiators are a unique form of ignition for energetic material because the current and voltage are tied together by impact loading on the crystal. This study examines the ignition response of an energetic composite composed of aluminum and molybdenum trioxide nanopowders to the arc generated from a lead zirconate and lead titanate piezocrystal. The mechanical stimuli used to activate the piezocrystal varied to assess ignition voltage, power, and delay time of aluminum–molybdenum trioxide for a range of bulk powder densities. Results show a high dielectric strength leads to faster ignition times because of the higher voltage delivered to the energetic. Ignition delay is under 0.4 ms, which is faster than observed with thermal or shock ignition. Electric ignition of composite energetic materials is a strong function of interparticle connectivity, and thus the role of bulk density on electrostatic discharge ignition sensitivity is a focus of this study. Results show that the ignition delay times are dependent on the powder bulk density with an optimum bulk density of 50%. Packing fractions and electrical conductivity were analyzed and aid in explaining the resulting ignition behavior as a function of bulk density.

  3. Investigation of ignition of thermoplastics through the Hot Wire Ignition Test

    E-Print Network [OSTI]

    De Araujo, Luiz Claudio Bonilla

    1998-01-01T23:59:59.000Z

    The purpose of this research was to investigate the ignition phenomena of selected polymeric materials using the Hot Wire Ignition Test. This test is prescribed by Underwriters Laboratories as one of various requirements for polymeric materials used...

  4. Korean oxygenates rule sparks MTBE capacity plans

    SciTech Connect (OSTI)

    Kim, Hyung-Jin

    1994-06-15T23:59:59.000Z

    The Korean government`s strict standard for gasoline sold domestically is expected to have a significant impact on the methyl tert-butyl ether (MTBE) market. The mandate-requiring gasoline oxygen content of 0.5% this year, 0.75% by 1996, and 1.0% by 1998-has sparked a rush by Korean refineries to build new MTBE plants. If expansion plans are carried out, Korea`s MTBE capacity will increase from 280,000 m.t./year to 650,000 m.t./year by 1996, far surpassing predicted demand. Honam Oil, part of the Lucky Group, plans startup of a 100,000-m.t./year unit at Yeochon by early 1996. In addition, by the end of 1996 Ssangyong Oil will bring a 100,000-m.t./year unit onstream.

  5. Fast ignition of inertial confinement fusion targets

    SciTech Connect (OSTI)

    Gus'kov, S. Yu., E-mail: guskov@sci.lebedev.ru [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation)

    2013-01-15T23:59:59.000Z

    Results of studies on fast ignition of inertial confinement fusion (ICF) targets are reviewed. The aspects of the fast ignition concept, which consists in the separation of the processes of target ignition and compression due to the synchronized action of different energy drivers, are considered. Criteria for the compression ratio and heating rate of a fast ignition target, the energy balance, and the thermonuclear gain are discussed. The results of experimental and theoretical studies of the heating of a compressed target by various types of igniting drivers, namely, beams of fast electrons and light ions produced under the action of a petawatt laser pulse on the target, a heavy-ion beam generated in the accelerator, an X-ray pulse, and a hydrodynamic flow of laser-accelerated matter, are analyzed. Requirements to the igniting-driver parameters that depend on the fast ignition criteria under the conditions of specific target heating mechanisms, as well as possibilities of practical implementation of these requirements, are discussed. The experimental programs of various laboratories and the prospects of practical implementation of fast ignition of ICF targets are reviewed. To date, fast ignition is the most promising method for decreasing the ignition energy and increasing the thermonuclear gain of an ICF plasma. A large number of publications have been devoted to investigations of this method and adjacent problems of the physics of igniting drivers and their interaction with plasma. This review presents results of only some of these studies that, in the author's opinion, allow one to discuss in detail the main physical aspects of the fast ignition concept and understand the current state and prospects of studies in this direction.

  6. NUMERICAL MODELLING OF THERMAL-ELECTRICAL PHENOMENA IN SPARK PLASMA SINTERING

    E-Print Network [OSTI]

    Boyer, Edmond

    NUMERICAL MODELLING OF THERMAL-ELECTRICAL PHENOMENA IN SPARK PLASMA SINTERING P. Mondaleka , L'Etudes Structurales), France c Université Paul Sabatier, Toulouse, France Abstract. Spark Plasma Sintering belongs: Finite element method, Spark plasma sintering, powder compaction. INTRODUCTION Spark Plasma Sintering

  7. An Experimental Study of Microfabricated Nickel Spark Plug Georgia Institute of technology

    E-Print Network [OSTI]

    electrodeposition through polymer molds. The nickel spark plugs are tested at 20 Hz using spark energies of 5 mAn Experimental Study of Microfabricated Nickel Spark Plug Georgia Institute of technology Atlanta presents experimental. results of the erosion and wear characteristics of micromachined nickel spark plugs

  8. Modelling piloted ignition of wood and plastics

    SciTech Connect (OSTI)

    Blijderveen, Maarten van [TNO, Schoemakerstraat 97, 2628 VK Delft (Netherlands); University of Twente, Department of Thermal Engineering, Drienerlolaan 5, 7522 NB Enschede (Netherlands); Bramer, Eddy A. [University of Twente, Department of Thermal Engineering, Drienerlolaan 5, 7522 NB Enschede (Netherlands); Brem, Gerrit, E-mail: g.brem@utwente.nl [University of Twente, Department of Thermal Engineering, Drienerlolaan 5, 7522 NB Enschede (Netherlands)

    2012-09-15T23:59:59.000Z

    Highlights: Black-Right-Pointing-Pointer We model piloted ignition times of wood and plastics. Black-Right-Pointing-Pointer The model is applied on a packed bed. Black-Right-Pointing-Pointer When the air flow is above a critical level, no ignition can take place. - Abstract: To gain insight in the startup of an incinerator, this article deals with piloted ignition. A newly developed model is described to predict the piloted ignition times of wood, PMMA and PVC. The model is based on the lower flammability limit and the adiabatic flame temperature at this limit. The incoming radiative heat flux, sample thickness and moisture content are some of the used variables. Not only the ignition time can be calculated with the model, but also the mass flux and surface temperature at ignition. The ignition times for softwoods and PMMA are mainly under-predicted. For hardwoods and PVC the predicted ignition times agree well with experimental results. Due to a significant scatter in the experimental data the mass flux and surface temperature calculated with the model are hard to validate. The model is applied on the startup of a municipal waste incineration plant. For this process a maximum allowable primary air flow is derived. When the primary air flow is above this maximum air flow, no ignition can be obtained.

  9. Heating National Ignition Facility, Realistic Financial Planning...

    Broader source: Energy.gov (indexed) [DOE]

    628 National Ignition Facility Realistic Financial Planning Rapid Modification are Essential Lessons Learned Report Apr 2010.pdf More Documents & Publications EIS-0236: Record of...

  10. Igniter containing titanium hydride and potassium perchlorate

    DOE Patents [OSTI]

    Dietzel, Russel W. (Albuquerque, NM); Leslie, William B. (Albuquerque, NM)

    1976-01-01T23:59:59.000Z

    An explosive device is described which employs a particular titanium hydride-potassium perchlorate composition directly ignitible by an electrical bridgewire.

  11. High-Efficiency Clean Combustion Design for Compression Ignition...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    High-Efficiency Clean Combustion Design for Compression Ignition Engines High-Efficiency Clean Combustion Design for Compression Ignition Engines Presentation given at DEER 2006,...

  12. Effects of Ignition Quality and Fuel Composition on Critical...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Effects of Ignition Quality and Fuel Composition on Critical Equivalence Ratio Effects of Ignition Quality and Fuel Composition on Critical Equivalence Ratio Our research shows...

  13. Advanced CFD Models for High Efficiency Compression Ignition...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    CFD Models for High Efficiency Compression Ignition Engines Advanced CFD Models for High Efficiency Compression Ignition Engines Advanced CFD models for high efficiency...

  14. High Fidelity Modeling of Premixed Charge Compression Ignition...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Fidelity Modeling of Premixed Charge Compression Ignition Engines High Fidelity Modeling of Premixed Charge Compression Ignition Engines Most accurate and detailed chemical kinetic...

  15. Fuel Effects on Ignition and Their Impact on Advanced Combustion...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Ignition and Their Impact on Advanced Combustion Engines Fuel Effects on Ignition and Their Impact on Advanced Combustion Engines Presentation given at DEER 2006, August 20-24,...

  16. alcohol ignition interlock: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    on the Fusion Ignition Research Experiment (FIRE), a tokamak designed for burning plasma research. Engineering 58 The National Ignition Campaign Presentation to Plasma Physics and...

  17. ENHANCED IGNITION FOR I.C. ENGINES WITH PREMIXED CHARGE

    E-Print Network [OSTI]

    Dale, J.D.

    2013-01-01T23:59:59.000Z

    Igniter for Internal Combustion Engines," SAE Paper 760764.Emissions from an Internal Combustion Engine,'' Combusti and11 Laser Ignited Internal Combustion Engine -An Experimental

  18. Effect of Premixed Charge Compression Ignition on Vehicle Fuel...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Premixed Charge Compression Ignition on Vehicle Fuel Economy and Emissions Reduction over Transient Driving Cycles Effect of Premixed Charge Compression Ignition on Vehicle Fuel...

  19. Fuel quantity modulation in pilot ignited engines

    DOE Patents [OSTI]

    May, Andrew

    2006-05-16T23:59:59.000Z

    An engine system includes a first fuel regulator adapted to control an amount of a first fuel supplied to the engine, a second fuel regulator adapted to control an amount of a second fuel supplied to the engine concurrently with the first fuel being supplied to the engine, and a controller coupled to at least the second fuel regulator. The controller is adapted to determine the amount of the second fuel supplied to the engine in a relationship to the amount of the first fuel supplied to the engine to operate in igniting the first fuel at a specified time in steady state engine operation and adapted to determine the amount of the second fuel supplied to the engine in a manner different from the relationship at steady state engine operation in transient engine operation.

  20. Mutual colliding impact fast ignition

    SciTech Connect (OSTI)

    Winterberg, Friedwardt, E-mail: winterbe@unr.edu [Department of Physics, College of Science, University of Nevada, Reno, 1664 N. Virginia Street, Reno, Nevada 89557-0220 (United States)

    2014-09-15T23:59:59.000Z

    It is proposed to apply the well established colliding beam technology of high energy physics to the fast hot spot ignition of a highly compressed DT (deuterium-tritium) target igniting a larger D (deuterium) burn, by accelerating a small amount of solid deuterium, and likewise a small amount of tritium, making a head-on collision in the center of the target, projecting them through conical ducts situated at the opposite side of the target and converging in its center. In their head-on collision, the relative collision velocity is 5/3 times larger compared to the collision velocity of a stationary target. The two pieces have for this reason to be accelerated to a smaller velocity than would otherwise be needed to reach upon impact the same temperature. Since the velocity distribution of the two head-on colliding projectiles is with its two velocity peaks non-Maxwellian, the maximum cross section velocity product turns out to be substantially larger than the maximum if averaged over a Maxwellian. The D and T projectiles would have to be accelerated with two sabots driven by powerful particle or laser beams, permitting a rather large acceleration length. With the substantially larger cross section-velocity product by virtue of the non-Maxwellian velocity distribution, a further advantage is that the head-on collision produces a large magnetic field by the thermomagnetic Nernst effect, enhancing propagating burn. With this concept, the ignition of the neutron-less hydrogen-boron (HB{sup 11}) reaction might even be possible in a heterogeneous assembly of the hydrogen and the boron to reduce the bremsstrahlung-losses, resembling the heterogeneous assembly in a graphite-natural uranium reactor, there to reduce the neutron losses.

  1. Combustion, Control, and Fuel Effects in a Spark Assisted HCCI Engine Equipped with Variable Valve Timing

    SciTech Connect (OSTI)

    Bunting, Bruce G [ORNL

    2006-01-01T23:59:59.000Z

    Widespread implementation of homogeneous charge compression ignition (HCCI) engines is presently hindered by stability, control, and load range issues. Although the operable HCCI speed/load range is expanding, it is likely that the initial HCCI engines will rely on conventional combustion for part of the operating cycle. In the present study, we have investigated the role of fuel properties and chemistry on the operation of a spark-assisted gasoline HCCI engine. The engine employed is a single cylinder, 500 cc, port fuel injected research engine, operating near lambda = 1.0 and equipped with hydraulic variable valve actuation. HCCI is initiated by early exhaust valve closing to retain exhaust in the cylinder, thereby increasing the cylinder gas temperature. This is also referred to as a 'negative overlap' strategy. A total of 10 custom blended gasolines and three different batches of indolene from two suppliers were run at 5 speed-load combinations and performance was characterized by timing sweeps. Within the quality of the data set, we can say the all fuels provided equivalent combustion and performance characteristics when compared at the same combustion phasing. The fuels did, however, require different degrees of retained exhaust as measured by exhaust valve closing angle to achieve the same combustion phasing. Fuels with higher octane sensitivity were found to ignite more easily or more quickly and to burn more quickly than fuels with lower octane sensitivity. This is an expected result since the engine is naturally aspirated and operates with high compression temperatures due to the high retained exhaust fraction and recompression.

  2. Scientists ignite aluminum water mix

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del Sol HomeFacebook Twitter PrincipalfuelTorus ExperimentScientists ignite aluminum

  3. Fusion Ignition Research Experiment Engineering Status Report

    E-Print Network [OSTI]

    of the world. The FIRE web site has been chosen as a selection for the Scout Report for Science and EngineeringFusion Ignition Research Experiment -FIRE- Engineering Status Report For Fiscal Year 2000 Issued on the Fusion Ignition Research Experiment (FIRE), a tokamak designed for burning plasma research. Engineering

  4. Weapons Activities/ Inertial Confinement Fusion Ignition

    E-Print Network [OSTI]

    Facility (NIF) will extend HEDP experiments to include access to thermonuclear burn conditions's Stockpile Stewardship Program (SSP) through three strategic objectives: Achieve thermonuclear ignition thermonuclear ignition to the national nuclear weapons program was one of the earliest motivations of the ICF

  5. Eutectic Al2O3-GdAlO3 composite consolidated by combined rapid quenching and spark plasma sintering technique

    E-Print Network [OSTI]

    Han, Young Hwan; Nagata, M; Uekawa, N; Kakegawa, K

    2004-01-01T23:59:59.000Z

    rapid quenching and spark plasma sintering technique Y. H.conventional and spark plasma sintering (SPS). Conventionalstructure, Rapid quenching, Spark plasma sintering. Dr Han (

  6. Synthesis and characterization of aluminium–alumina micro- and nano-composites by spark plasma sintering

    SciTech Connect (OSTI)

    Dash, K., E-mail: khushbudash@gmail.com; Chaira, D.; Ray, B.C.

    2013-07-15T23:59:59.000Z

    Graphical abstract: The evolution of microstructure by varying the particle size of reinforcement in the matrix employing spark plasma sintering has been demonstrated here in Al–Al{sub 2}O{sub 3} system. An emphasis has been laid on varying the reinforcement particle size and evaluating the microstructural morphologies and their implications on mechanical performance of the composites. Nanocomposites of 0.5, 1, 3, 5, 7 volume % alumina (average size < 50 nm) reinforced in aluminium matrix were fabricated by powder metallurgy route using spark plasma sintering technique technique at a temperature of 773 K and pressure of 50 MPa. Another set of specimens having composition 1, 5, 20 vol.% of alumina (average size ? 10 ?m) had been fabricated to compare the physical as well as mechanical attributes of the microcomposite as well as the nanocomposites. These micro- and nano-composites have been characterized using X-ray diffraction, scanning electron microscopy and transmission electron microscopy followed by density, microhardness and nanoindentation measurements. The alumina nanoparticles revealed an interface showing appreciable physical intimacy with the aluminium matrix compared to that of the alumina microparticles. The interfacial integrity in case of nanocomposites is better than in the microcomposite which has been studied using microscopic techniques. Spark plasma sintering imparts enhanced densification as well as matrix-reinforcement proximity which has been corroborated with the experimental results. - Highlights: • The Al–Al{sub 2}O{sub 3} micro- and nano-composites fabricated by spark plasma sintering. • Better matrix-reinforcement integrity in nanocomposites than microcomposites. • Spark plasma sintering method results in higher density and hardness values. • High density and hardness values of nanocomposites than microcomposites. • High dislocation density in spark plasma sintered Al–Al{sub 2}O{sub 3} composites. - Abstract: In the present study, an emphasis has been laid on evaluation of the microstructural morphologies and their implications on mechanical performance of the composites by varying the reinforcement particle size. Nanocomposites of 0.5, 1, 3, 5, 7 volume % alumina (average size < 50 nm) and microcomposites of 1, 5, 20 volume % of alumina (average size ? 10 ?m) reinforced in aluminium matrix were fabricated by spark plasma sintering technique at a temperature of 773 K and pressure of 50 MPa. These micro- and nano-composites have been characterized using X-ray diffraction, scanning electron microscopy and transmission electron microscopy followed by density, microhardness and nanoindentation hardness measurements. The alumina nanoparticles revealed appreciable physical intimacy with the aluminium matrix than that of alumina microparticles. The highest nanohardness recorded 0.85 GPa and 99% densification for 7 and 1 vol.% Al–Al{sub 2}O{sub 3} nancomposites respectively. Spark plasma sintering imparts enhanced densification and matrix-reinforcement proximity which have been corroborated with the experimental results.

  7. Laser ignition of aluminum nanoparticles in air

    SciTech Connect (OSTI)

    Sandstrom, M. M. (Mary M.); Oschwald, D. M. (David M); Son, S. F. (Steven F.)

    2004-01-01T23:59:59.000Z

    This paper reports on recent experiments of the ignition of nanoaluminum in air by CO{sub 2} laser heating. Ignition time and temperature were measured as a function of Al particle size and laser power. The ignition time was determined by high-speed digital images and frrst light as determined by a photodiode. The ignition delay increases with increasing particle size, and the decreasing laser power. Two stage burning is observed. The first reaction takes place on the surface of the powder sample and moves from the center to the edges followed by the second reaction, which takes place within the bulk of the sample. As the particles size increases the material is less likely to burn through out, leaving behind unreacted Al powder.

  8. National Ignition Facility Management Descriptions Revision 9

    SciTech Connect (OSTI)

    Moses, E I

    2004-01-01T23:59:59.000Z

    The purpose of this document is to describe the National Ignition Facility (NIF) Project Organization and the top-level roles and responsibilities of the managers charged with executing the Project.

  9. The Application of High Energy Ignition and Boosting/Mixing Technology to Increase Fuel Economy in Spark Ignition Gasoline Engines by Increasing EGR Dilution Capability

    Broader source: Energy.gov [DOE]

    2013 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting

  10. Ignition methods and apparatus using microwave energy

    DOE Patents [OSTI]

    DeFreitas, Dennis M. (Oxford, NY); Darling, Timothy W. (Los Alamos, NM); Migliori, Albert (Santa Fe, NM); Rees, Daniel E. (Los Alamos, NM)

    1997-01-01T23:59:59.000Z

    An ignition apparatus for a combustor includes a microwave energy source that emits microwave energy into the combustor at a frequency within a resonant response of the combustor, the combustor functioning as a resonant cavity for the microwave energy so that a plasma is produced that ignites a combustible mixture therein. The plasma preferably is a non-contact plasma produced in free space within the resonant cavity spaced away from with the cavity wall structure and spaced from the microwave emitter.

  11. Energy enhancement for deuteron beam fast ignition of a precompressed inertial confinement fusion target

    SciTech Connect (OSTI)

    Yang Xiaoling; Miley, George H. [Department of Nuclear, Plasma and Radiological Engineering, University of Illinois, Urbana, Illinois 61801 (United States); Flippo, Kirk A. [P-24 Plasma Physics, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Hora, Heinrich [University of New South Wales, Sydney 2052 (Australia)

    2011-03-15T23:59:59.000Z

    Fast Ignition (FI) is recognized as a potentially promising approach to achieve the high-energy-gain target performance needed for commercial inertial confinement fusion. Here we consider deuteron beam driven FI which provides not only the 'hot spot' ignition spark, but also extra ''bonus'' fusion energy through reactions in the target. In this study, we estimate the impact of the added deposition energy due to the fusion reactions occurring, based on calculations using a modified energy multiplication factor F{sub c}. The deuteron beam energy deposition range and time are also evaluated in order to estimate the desired deuteron initial energy. It is shown that an average of 30% extra energy can be gained from deuterons with 1 MeV initial energy and 12% from deuterons with 3 MeV initial energy. These results indicate that the energy benefit of this approach could be significant, but a much more comprehensive calculation is needed to realize a full 3D design for realistic experimental studies.

  12. A laser triggered vacuum spark x-ray lithography source

    E-Print Network [OSTI]

    Keating, Richard Allen

    1987-01-01T23:59:59.000Z

    ionized state or the physical processes occurring 15 in a high temperature plasma. There are many advantages to the use of the vacuum spark as an x-ray source; the simplicity of the machine is one. The x-ray output is within the range usable for x-ray... spark apparatus ha- been studied here to determine its applicability to x-ray lithography. A capacitor which stored approximately 3 KJ supplied most of the energy for the plasma. A Nd-YAG laser was used to supply electrons and metallic atoms...

  13. Spark Solar Australia Proprietary Limited | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualProperty Edit with formSoutheastern IL Elec Coop, IncSouthwesternSpark Energy, LPSparkSpark

  14. National Ignition Facility Quality Assurance Program Plan. Revision 1

    SciTech Connect (OSTI)

    Wolfe, C.R.; Yatabe, J.

    1996-09-01T23:59:59.000Z

    The National Ignition Facility (NIF) is a key constituent of the Department of Energy`s Stockpile Stewardship Program. The NIF will use inertial confinement fusion (ICF) to produce ignition and energy gain in ICF targets, and will perform weapons physics and high-energy- density experiments in support of national security and civilian objectives. The NIF Project is a national facility involving the collaboration of several DOE laboratories and subcontractors, including Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Sandia National Laboratory (SNL), and the University of Rochester Laboratory for Laser Energetics (UR/LLE). The primary mission of the NIF Project is the construction and start-up operation of laser-based facilities that will demonstrate fusion ignition in the laboratory to provide nuclear-weapons-related physics data, and secondarily, to propagate fusion burn aimed at developing a potential source of civilian energy. To support the accomplishment of this very important mission, the LLNL Laser Directorate created the NIF Project Office to organize and bring about the Project. The NIF Project Office has established this Quality Assurance Program to ensure its success. This issue of the Quality Assurance Program Plan (QAPP) adds the requirements for the conduct of Title 11 design, construction, procurement, and Title III engineering. This QAPP defines and describes the program-the management system-for specifying, achieving, and assuring the quality of all NIF Project work consistent with the policies of the Laboratory and the Laser Directorate.

  15. Spark Plasma Sintering of Nanocrystalline Cu and Cu-10 Wt Pct Pb Alloy

    E-Print Network [OSTI]

    Srivastava, Kumar Vaibhav

    Spark Plasma Sintering of Nanocrystalline Cu and Cu-10 Wt Pct Pb Alloy AMIT S. SHARMA, KRISHANU temperature of 623 K (350 °C) using spark plasma sintering (SPS) in argon atmosphere at a pressure of 100 MPa to synthesize the bulk nanostructured Cu-10 wt pct Pb hypo-monotectic alloy by a novel technique, spark plasma

  16. Spark plasma sintering of Mn-Al-C hard magnets , E Fazakas2

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Spark plasma sintering of Mn-Al-C hard magnets A Pasko1 , M LoBue1 , E Fazakas2 , L K Varga2 and F characterization of isotropic Mn-Al-C bulk samples obtained by spark plasma sintering (SPS) is reported by spark plasma sintering (SPS). This technique, to our knowledge, has not been used for preparation of Mn

  17. Densification and microstructure development in spark plasma sintered WC6 wt% ZrO2 nanocomposites

    E-Print Network [OSTI]

    Srivastava, Kumar Vaibhav

    Densification and microstructure development in spark plasma sintered WC­6 wt% ZrO2 nanocomposites nanocomposite, spark plasma sintered at 1300 °C, for varying times of up to 20 min. The primary aim of this work investigation indicated that ZrO2 in the spark plasma sintered nanocomposite adopted an orthorhombic crystal

  18. Novel Spark Plugs Improve Energy Efficiency of Compressed Natural

    E-Print Network [OSTI]

    Novel Spark Plugs Improve Energy Efficiency of Compressed Natural Gas Engines Energy Innovations use affects climate change. Vehicles operating on compressed natural gas reduce petroleum fuel use, the vast majority of compressed natural gas (CNG) engines are used in transit buses serving the public

  19. UW -Center for Intelligent Materials and Systems Design of Energy Absorption Bases on Porous

    E-Print Network [OSTI]

    Taya, Minoru

    Materials and Systems Material Processing and Testing NiTi Alloy Powder Spark Plasma Sintering (SPS) Porous Plasma Sintering (SPS) #12;UW - Center for Intelligent Materials and Systems Schematic Sketch of Spark for Intelligent Materials and Systems Material Processing and Testing NiTi Alloy Powder Spark Plasma Sintering Ni

  20. A Kirkpatrick-Baez microscope for the National Ignition Facility

    SciTech Connect (OSTI)

    Pickworth, L. A., E-mail: pickworth1@llnl.gov; McCarville, T.; Decker, T.; Pardini, T.; Ayers, J.; Bell, P.; Bradley, D.; Brejnholt, N. F.; Izumi, N.; Mirkarimi, P.; Pivovaroff, M.; Smalyuk, V.; Vogel, J.; Walton, C. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Kilkenny, J. [General Atomics, San Diego, California 92121 (United States)

    2014-11-15T23:59:59.000Z

    Current pinhole x ray imaging at the National Ignition Facility (NIF) is limited in resolution and signal throughput to the detector for Inertial Confinement Fusion applications, due to the viable range of pinhole sizes (10–25 ?m) that can be deployed. A higher resolution and throughput diagnostic is in development using a Kirkpatrick-Baez microscope system (KBM). The system will achieve <9 ?m resolution over a 300 ?m field of view with a multilayer coating operating at 10.2 keV. Presented here are the first images from the uncoated NIF KBM configuration demonstrating high resolution has been achieved across the full 300 ?m field of view.

  1. The Effects of Charge Motion and Laminar Flame Speed on Late Robust Combustion in a Spark-Ignition Engine

    E-Print Network [OSTI]

    Cheng, Wai K.

    The effects of charge motion and laminar flame speeds on combustion and exhaust temperature have been studied by using an air jet in the intake flow to produce an adjustable swirl or tumble motion, and by replacing the ...

  2. Sandia National Laboratories participation in the National Ignition Facility project

    SciTech Connect (OSTI)

    Boyes, J.; Boyer, W.; Chael, J.; Cook, D.; Cook, W.; Downey, T.; Hands, J.; Harjes, C.; Leeper, R.; McKay, P.; Micano, P.; Olson, R.; Porter, J.; Quintenz, J.; Roberts, V.; Savage, M.; Simpson, W.; Seth, A.; Smith, R.; Wavrik, M.; Wilson, M.

    1996-08-01T23:59:59.000Z

    The National Ignition Facility is a $1.1B DOE Defense Programs Inertial Confinement Fusion facility supporting the Science Based Stockpile Stewardship Program. The goal of the facility is to achieve fusion ignition and modest gain in the laboratory. The NIF project is responsible for the design and construction of the 192 beam, 1.8 MJ laser necessary to meet that goal. - The project is a National project with participation by Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Sandia National Laboratory (SNL), the University of Rochester Laboratory for Laser Energetics (URLLE) and numerous industrial partners. The project is centered at LLNL which has extensive expertise in large solid state lasers. The other partners in the project have negotiated their participation based on the specific expertise they can bring to the project. In some cases, this negotiation resulted in the overall responsibility for a WBS element; in other cases, the participating laboratories have placed individuals in the project in areas that need their individual expertise. The main areas of Sandia`s participation are in the management of the conventional facility design and construction, the design of the power conditioning system, the target chamber system, target diagnostic instruments, data acquisition system and several smaller efforts in the areas of system integration and engineering analysis. Sandia is also contributing to the technology development necessary to support the project by developing the power conditioning system and several target diagnostics, exploring alternate target designs, and by conducting target experiments involving the ``foot`` region of the NIF power pulse. The project has just passed the mid-point of the Title I (preliminary) design phase. This paper will summarize Sandia`s role in supporting the National Ignition Facility and discuss the areas in which Sandia is contributing. 3 figs.

  3. Final report on development of Pulse Arrested Spark Discharge (PASD) for aging aircraft wiring application.

    SciTech Connect (OSTI)

    Lockner, Thomas Ramsbeck; Howard, R. Kevin; Peńa, Gary Edward; Schneider, Larry X.; Higgins, Matthew B.; Glover, Steven Frank

    2006-09-01T23:59:59.000Z

    Pulsed Arrested Spark Discharge (PASD) is a Sandia National Laboratories Patented, non-destructive wiring system diagnostic that has been developed to detect defects in aging wiring systems in the commercial aircraft fleet. PASD was previously demonstrated on relatively controlled geometry wiring such as coaxial cables and shielded twisted-pair wiring through a contract with the U.S. navy and is discussed in a Sandia National Laboratories report, SAND2001-3225 ''Pulsed Arrested Spark Discharge (PASD) Diagnostic Technique for the Location of Defects in Aging Wiring Systems''. This report describes an expansion of earlier work by applying the PASD technique to unshielded twisted-pair and discrete wire configurations commonly found in commercial aircraft. This wiring is characterized by higher impedances as well as relatively non-uniform impedance profiles that have been found to be challenging for existing aircraft wiring diagnostics. Under a three year contract let by the Federal Aviation Administration, Interagency Agreement DTFA-03-00X90019, this technology was further developed for application on aging commercial aircraft wiring systems. This report describes results of the FAA program with discussion of previous work conducted under U.S. Department of Defense funding.

  4. Submission of Notice of Termination of Coverage Under the National Pollutant Discharge Elimination System General Permit No. CAS000002 for WDID No. 201C349114, Lawrence Livermore National Laboratory Ignition Facility Construction Project

    SciTech Connect (OSTI)

    Brunckhorst, K

    2009-04-21T23:59:59.000Z

    This is the completed Notice of Termination of Coverage under the General Permit for Storm Water Discharges Associated with Construction Activity. Construction activities at the National Ignition Facility Construction Project at Lawrence Livermore National Laboratory are now complete. The Notice of Termination includes photographs of the completed construction project and a vicinity map.

  5. Analytical model for fast-shock ignition

    SciTech Connect (OSTI)

    Ghasemi, S. A., E-mail: abo.ghasemi@yahoo.com; Farahbod, A. H. [Plasma Physics Research School, NSTRI, North Kargar Avenue, Tehran (Iran, Islamic Republic of); Sobhanian, S. [Department of Physics, Tabriz University, Tabriz (Iran, Islamic Republic of)

    2014-07-15T23:59:59.000Z

    A model and its improvements are introduced for a recently proposed approach to inertial confinement fusion, called fast-shock ignition (FSI). The analysis is based upon the gain models of fast ignition, shock ignition and considerations for the fast electrons penetration into the pre-compressed fuel to examine the formation of an effective central hot spot. Calculations of fast electrons penetration into the dense fuel show that if the initial electron kinetic energy is of the order ?4.5 MeV, the electrons effectively reach the central part of the fuel. To evaluate more realistically the performance of FSI approach, we have used a quasi-two temperature electron energy distribution function of Strozzi (2012) and fast ignitor energy formula of Bellei (2013) that are consistent with 3D PIC simulations for different values of fast ignitor laser wavelength and coupling efficiency. The general advantages of fast-shock ignition in comparison with the shock ignition can be estimated to be better than 1.3 and it is seen that the best results can be obtained for the fuel mass around 1.5 mg, fast ignitor laser wavelength ?0.3??micron and the shock ignitor energy weight factor about 0.25.

  6. Thermonuclear supernova simulations with stochastic ignition

    E-Print Network [OSTI]

    W. Schmidt; J. C. Niemeyer

    2005-10-14T23:59:59.000Z

    We apply an ad hoc model for dynamical ignition in three-dimensional numerical simulations of thermonuclear supernovae assuming pure deflagrations. The model makes use of the statistical description of temperature fluctuations in the pre-supernova core proposed by Wunsch & Woosley (2004). Randomness in time is implemented by means of a Poisson process. We are able to vary the explosion energy and nucleosynthesis depending on the free parameter of the model which controls the rapidity of the ignition process. However, beyond a certain threshold, the strength of the explosion saturates and the outcome appears to be robust with respect to number of ignitions. In the most energetic explosions, we find about 0.75 solar masses of iron group elements. Other than in simulations with simultaneous multi-spot ignition, the amount of unburned carbon and oxygen at radial velocities of a few 1000 km/s tends to be reduced for an ever increasing number of ignition events and, accordingly, more pronounced layering results.

  7. National Ignition Facility project acquisition plan revision 1

    SciTech Connect (OSTI)

    Clobes, A.R.

    1996-10-01T23:59:59.000Z

    The purpose of this National Ignition Facility Acquisition Plan is to describe the overall procurement strategy planned for the National Ignition Facility M Project. It was prepared for the NIP Prood Office by the NIF Procurement Manager.

  8. Ignition of deuterium-tritium fuel targets

    DOE Patents [OSTI]

    Musinski, D.L.; Mruzek, M.T.

    1991-08-27T23:59:59.000Z

    Disclosed is a method of igniting a deuterium-tritium ICF fuel target to obtain fuel burn in which the fuel target initially includes a hollow spherical shell having a frozen layer of DT material at substantially uniform thickness and cryogenic temperature around the interior surface of the shell. The target is permitted to free-fall through a target chamber having walls heated by successive target ignitions, so that the target is uniformly heated during free-fall to at least partially melt the frozen fuel layer and form a liquid single-phase layer or a mixed liquid/solid bi-phase layer of substantially uniform thickness around the interior shell surface. The falling target is then illuminated from exteriorly of the chamber while the fuel layer is at substantially uniformly single or bi-phase so as to ignite the fuel layer and release energy therefrom. 5 figures.

  9. Ignition of deuterium-trtium fuel targets

    DOE Patents [OSTI]

    Musinski, Donald L. (Saline, MI); Mruzek, Michael T. (Britton, MI)

    1991-01-01T23:59:59.000Z

    A method of igniting a deuterium-tritium ICF fuel target to obtain fuel burn in which the fuel target initially includes a hollow spherical shell having a frozen layer of DT material at substantially uniform thickness and cryogenic temperature around the interior surface of the shell. The target is permitted to free-fall through a target chamber having walls heated by successive target ignitions, so that the target is uniformly heated during free-fall to at least partially melt the frozen fuel layer and form a liquid single-phase layer or a mixed liquid/solid bi-phase layer of substantially uniform thickness around the interior shell surface. The falling target is then illuminated from exteriorly of the chamber while the fuel layer is at substantially uniformly single or bi-phase so as to ignite the fuel layer and release energy therefrom.

  10. DOE/EIS-0236, Oakland Operations Office, National Ignition Facility...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    DOEEIS-0236, Oakland Operations Office, National Ignition Facility Final Supplemental Environmental Impact Statement to the Stockpile Stewardship and Management Programmatic...

  11. Gated x-ray detector for the National Ignition Facility

    SciTech Connect (OSTI)

    Oertel, John A.; Aragonez, Robert; Archuleta, Tom; Barnes, Cris; Casper, Larry; Fatherley, Valerie; Heinrichs, Todd; King, Robert; Landers, Doug; Lopez, Frank; Sanchez, Phillip; Sandoval, George; Schrank, Lou; Walsh, Peter; Bell, Perry; Brown, Matt; Costa, Robert; Holder, Joe; Montelongo, Sam; Pederson, Neal [Los Alamos National Laboratory, Los Alamos, New Mexico 87544 (United States); Lawrence Livermore National Laboratory, Livermore, California 94551-0808 (United States); VI Control Systems Ltd., Los Alamos, New Mexico 87544 (United States)

    2006-10-15T23:59:59.000Z

    Two new gated x-ray imaging cameras have recently been designed, constructed, and delivered to the National Ignition Facility in Livermore, CA. These gated x-Ray detectors are each designed to fit within an aluminum airbox with a large capacity cooling plane and are fitted with an array of environmental housekeeping sensors. These instruments are significantly different from earlier generations of gated x-ray images due, in part, to an innovative impedance matching scheme, advanced phosphor screens, pulsed phosphor circuits, precision assembly fixturing, unique system monitoring, and complete remote computer control. Preliminary characterization has shown repeatable uniformity between imaging strips, improved spatial resolution, and no detectable impedance reflections.

  12. Controlling And Operating Homogeneous Charge Compression Ignition (Hcci) Engines

    DOE Patents [OSTI]

    Flowers, Daniel L. (San Leandro, CA)

    2005-08-02T23:59:59.000Z

    A Homogeneous Charge Compression Ignition (HCCI) engine system includes an engine that produces exhaust gas. A vaporization means vaporizes fuel for the engine an air induction means provides air for the engine. An exhaust gas recirculation means recirculates the exhaust gas. A blending means blends the vaporized fuel, the exhaust gas, and the air. An induction means inducts the blended vaporized fuel, exhaust gas, and air into the engine. A control means controls the blending of the vaporized fuel, the exhaust gas, and the air and for controls the inducting the blended vaporized fuel, exhaust gas, and air into the engine.

  13. FIREBALL: Fusion Ignition Rocket Engine with Ballistic Ablative Lithium Liner

    SciTech Connect (OSTI)

    Martin, Adam K.; Eskridge, Richard H.; Lee, Michael H. [Propulsion Research Center, NASA Marshall Space Flight Center XD22, Huntsville, AL 35812 (United States); Fimognari, Peter J. [Department of Physics, University of Alabama in Huntsville, Huntsville, AL 35899 (United States)

    2006-01-20T23:59:59.000Z

    Thermo-nuclear fusion may be the key to a high Isp, high specific power propulsion system. In a fusion system energy is liberated within, and imparted directly to, the propellant. In principle, this can overcome the performance limitations inherent in systems that require thermal power transfer across a material boundary, and/or multiple power conversion stages (NTR, NEP). A thermo-nuclear propulsion system, which attempts to overcome some of the problems inherent in the Orion concept, is described. A dense FRC plasmoid is accelerated to high velocity (in excess of 500 km/s) and is compressed into a detached liner (pulse unit). The kinetic energy of the FRC is converted into thermal and magnetic-field energy, igniting a fusion burn in the magnetically confined plasma. The fusion reaction serves as an ignition source for the liner, which is made out of detonable materials. The energy liberated in this process is converted to thrust by a pusher-plate, as in the classic Orion concept. However with this concept, the vehicle does not carry a magazine of autonomous pulse-units. By accelerating a second, heavier FRC, which acts as a piston, right behind the first one, the velocity required to initiate the fusion burn is greatly reduced.

  14. Production of S/sub 2/F/sub 10/ by SF/sub 6/ spark discharges

    SciTech Connect (OSTI)

    Sauers, I.; Votaw, P.C.; Griffin, G.D.

    1988-01-01T23:59:59.000Z

    The highly toxic compound S/sub 2/F/sub 10/ is formed in SF/sub 6/ following spark discharges. When the spark cell is dried, the S/sub 2/F/sub 10/ yield was 6.8 /times/ 10/sup /minus/11/ mol/J at an SF/sub 6/ pressure P = 133 kPa. Moisture appears to suppress the S/sub 2/F/sub 10/ yield, although once formed, the S/sub 2/F/sub 10/ is quite stable with respect to moisture. This could explain the variation in observation from experiment to experiment in the literature. These results also raise important questions as to the influence of drying agents that are used in high-voltage systems on the S/sub 2/F/sub 10/ yield. 13 refs., 2 figs., 1 tab.

  15. Numerical and experimental design of three-electrode spark gap for synthetic test circuits

    SciTech Connect (OSTI)

    Osmokrovic, P.; Lazarevic, Z.; Kusic, D. (Buleva Revolucije 73, Belgrade (Yugoslavia). Faculty of Electrical Engineering); Arsic, N. (Suncani Breg bb, Pristina (Yugoslavia). Faculty of Electrical Engineering)

    1994-07-01T23:59:59.000Z

    The development of a three-electrode spark gap used with synthetic circuit is considered in this paper. Two types of three-electrode gas insulated spark gaps have been tested: a spark gap with a third electrode being inside the main electrode, and a spark gap with a separate third electrode. Both types of spark gaps were theoretically sized in the optimal way. Several characteristics are determined experimentally: (1) the influence of the gas insulation parameters on the spark gap functioning, (2) the influence of the working and triggering voltages polarities on the spark gap functioning, (3) the influence of the triggering voltage rate-of-rise on the spark gap functioning and (4) the degree of spark gap erosion vs number of operations. Three types of gases were applied: SF6 gas, N2 gas and mixture of 60% SF6 with 40% N2. Also, three electrode materials were used: copper, steel and tungsten. The spark gap switching time and delay time are measured. The statistical analysis of results is presented.

  16. Focused shock spark discharge drill using multiple electrodes

    DOE Patents [OSTI]

    Moeny, William M. (Albuquerque, NM); Small, James G. (Albuquerque, NM)

    1988-01-01T23:59:59.000Z

    A spark discharge focused drill provided with one pulse forming line or a number of pulse forming lines. The pulse forming line is connected to an array of electrodes which would form a spark array. One of the electrodes of each of the array is connected to the high voltage side of the pulse forming line and the other electrodes are at ground potential. When discharged in a liquid, these electrodes produce intense focused shock waves that can pulverize or fracture rock. By delaying the firing of each group of electrodes, the drill can be steered within the earth. Power can be fed to the pulse forming line either downhole or from the surface area. A high voltage source, such as a Marx generator, is suitable for pulse charging the lines.

  17. National Ignition Facility Title II Design Plan

    SciTech Connect (OSTI)

    Kumpan, S

    1997-03-01T23:59:59.000Z

    This National Ignition Facility (NIF) Title II Design Plan defines the work to be performed by the NIF Project Team between November 1996, when the U.S. Department of Energy (DOE) reviewed Title I design and authorized the initiation of Title H design and specific long-lead procurements, and September 1998, when Title 11 design will be completed.

  18. Impacts assessment for the National Ignition Facility

    SciTech Connect (OSTI)

    Bay Area Economics

    1996-12-01T23:59:59.000Z

    This report documents the economic and other impacts that will be created by the National Ignition Facility (NIF) construction and ongoing operation, as well as the impacts that may be created by new technologies that may be developed as a result of NIF development and operation.

  19. Dark matter ignition of type Ia supernovae

    E-Print Network [OSTI]

    Bramante, Joseph

    2015-01-01T23:59:59.000Z

    Recent studies of low redshift type Ia supernovae (SNIa) indicate that half explode from less than Chandrasekhar mass white dwarfs, implying ignition must proceed from something besides the canonical criticality of Chandrasekhar mass SNIa progenitors. We show that $0.1-10$ PeV mass asymmetric dark matter, with imminently detectable nucleon scattering interactions, can accumulate to the point of self-gravitation in a white dwarf and collapse, shedding gravitational potential energy by scattering off nuclei, thereby heating the white dwarf and igniting the flame front that precedes SNIa. We combine data on SNIa masses with data on the ages of SNIa-adjacent stars. This combination reveals a $ 3 \\sigma$ inverse correlation between SNIa masses and ignition ages, which could result from increased capture of dark matter in 1.4 versus 1.1 solar mass white dwarfs. Future studies of SNIa in galactic centers will provide additional tests of dark-matter-induced type Ia ignition. Remarkably, both bosonic and fermionic SNI...

  20. Response to Comment on "The National Ignition Facility Laser Performance Status"

    SciTech Connect (OSTI)

    Haynam, C A; Sacks, R A; Moses, E I; Manes, K; Haan, S; Spaeth, M L

    2007-12-11T23:59:59.000Z

    We appreciate Stephen Bodner's continuing interest in the performance of the NIF laser system. However, we find it necessary to disagree with the conclusions he reached in his comments [Appl. Opt. 47, XXX (2008)] on 'National Ignition Facility Laser Performance Status' [Appl. Opt. 46, 3276 (2007)]. In fact, repeated and ongoing tests of the NIF beamlines have demonstrated that NIF can be expected not only to meet or exceed its requirements as established in the mid-1990s in the document National Ignition Facility Functional Requirements and Primary Criteria [Revision 1.3, Report NIF-LLNL-93-058 (1994)], but also to have the flexibility that provides for successfully meeting an ever expanding range of mission goals, including those of ignition.

  1. The National Ignition Facility: The Path to a Carbon-Free Energy Future

    SciTech Connect (OSTI)

    Stolz, C J

    2011-03-16T23:59:59.000Z

    The National Ignition Facility (NIF), the world's largest and most energetic laser system, is now operational at Lawrence Livermore National Laboratory (LLNL). The NIF will enable exploration of scientific problems in national strategic security, basic science and fusion energy. One of the early NIF goals centers on achieving laboratory-scale thermonuclear ignition and energy gain, demonstrating the feasibility of laser fusion as a viable source of clean, carbon-free energy. This talk will discuss the precision technology and engineering challenges of building the NIF and those we must overcome to make fusion energy a commercial reality.

  2. The ePLAS Code for Ignition Studies

    SciTech Connect (OSTI)

    Mason, Rodney J

    2012-09-20T23:59:59.000Z

    Inertial Confinement Fusion (ICF) presents unique opportunities for the extraction of clean energy from Fusion. Intense lasers and particle beams can create and interact with such plasmas, potentially yielding sufficient energy to satisfy all our national needs. However, few models are available to help aid the scientific community in the study and optimization of such interactions. This project enhanced and disseminated the computer code ePLAS for the early understanding and control of Ignition in ICF. ePLAS is a unique simulation code that tracks the transport of laser light to a target, the absorption of that light resulting in the generation and transport of hot electrons, and the heating and flow dynamics of the background plasma. It uses an implicit electromagnetic field-solving method to greatly reduce computing demands, so that useful target interaction studies can often be completed in 15 minutes on a portable 2.1 GHz PC. The code permits the rapid scoping of calculations for the optimization of laser target interactions aimed at fusion. Recent efforts have initiated the use of analytic equations of state (EOS), K-alpha image rendering graphics, allocatable memory for source-free usage, and adaption to the latest Mac and Linux Operating Systems. The speed and utility of ePLAS are unequaled in the ICF simulation community. This project evaluated the effects of its new EOSs on target heating, compared fluid and particle models for the ions, initiated the simultaneous use of both ion models in the code, and studied long time scale 500 ps hot electron deposition for shock ignition. ePLAS has been granted EAR99 export control status, permitting export without a license to most foreign countries. Beta-test versions of ePLAS have been granted to several Universities and Commercial users. The net Project was aimed at achieving early success in the laboratory ignition of thermonuclear targets and the mastery of controlled fusion power for the nation.

  3. Premix charge, compression ignition combustion system optimization |

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn'tOrigin of Contamination in235-1DepartmentPreheatedDepartmentofEA-97-12 |—ŹDepartment of

  4. IMPLODING IGNITION WAVES. I. ONE-DIMENSIONAL ANALYSIS

    SciTech Connect (OSTI)

    Kushnir, Doron; Waxman, Eli [Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot 76100 (Israel); Livne, Eli [Racah Institute of Physics, Hebrew University, Jerusalem (Israel)

    2012-06-20T23:59:59.000Z

    We show that converging spherical and cylindrical shock waves may ignite a detonation wave in a combustible medium, provided the radius at which the shocks become strong exceeds a critical radius, R{sub crit}. An approximate analytic expression for R{sub crit} is derived for an ideal gas equation of state and a simple (power-law-Arrhenius) reaction law, and shown to reproduce the results of numerical solutions. For typical acetylene-air experiments we find R{sub crit} {approx} 100 {mu}m (spherical) and R{sub crit} {approx} 1 mm (cylindrical). We suggest that the deflagration to detonation transition (DDT) observed in these systems may be due to converging shocks produced by the turbulent deflagration flow, which reaches sub- (but near) sonic velocities on scales >>R{sub crit}. Our suggested mechanism differs from that proposed by Zel'dovich et al., in which a fine-tuned spatial gradient in the chemical induction time is required to be maintained within the turbulent deflagration flow. Our analysis may be readily extended to more complicated equations of state and reaction laws. An order of magnitude estimate of R{sub crit} within a white dwarf at the pre-detonation conditions believed to lead to Type Ia supernova explosions is 0.1 km, suggesting that our proposed mechanism may be relevant for DDT initiation in these systems. The relevance of our proposed ignition mechanism to DDT initiation may be tested by both experiments and numerical simulations.

  5. Visualization of Target Inspection data at the National Ignition Facility

    SciTech Connect (OSTI)

    Potter, D; Antipa, N

    2012-02-16T23:59:59.000Z

    As the National Ignition Facility continues its campaign to achieve ignition, new methods and tools will be required to measure the quality of the target capsules used to achieve this goal. Techniques have been developed to measure capsule surface features using a phase-shifting diffraction interferometer and Leica Microsystems confocal microscope. These instruments produce multi-gigabyte datasets which consist of tens to hundreds of files. Existing software can handle viewing a small subset of an entire dataset, but none can view a dataset in its entirety. Additionally, without an established mode of transport that keeps the target capsules properly aligned throughout the assembly process, a means of aligning the two dataset coordinate systems is needed. The goal of this project is to develop web based software utilizing WebGL which will provide high level overview visualization of an entire dataset, with the capability to retrieve finer details on demand, in addition to facilitating alignment of multiple datasets with one another based on common features that have been visually identified by users of the system.

  6. Fast Ignition Experimental and Theoretical Studies

    SciTech Connect (OSTI)

    Akli, K

    2006-10-20T23:59:59.000Z

    We are becoming dependent on energy more today than we were a century ago, and with increasing world population and booming economies, sooner or later our energy sources will be exhausted. Moreover, our economy and welfare strongly depends on foreign oil and in the shadow of political uncertainties, there is an urgent need for a reliable, safe, and cheap energy source. Thermonuclear fusion, if achieved, is that source of energy which not only will satisfy our demand for today but also for centuries to come. Today, there are two major approaches to achieve fusion: magnetic confinement fusion (MFE) and inertial confinement fusion (ICF). This dissertation explores the inertial confinement fusion using the fast ignition concept. Unlike the conventional approach where the same laser is used for compression and ignition, in fast ignition separate laser beams are used. This dissertation addresses three very important topics to fast ignition inertial confinement fusion. These are laser-to-electron coupling efficiency, laser-generated electron beam transport, and the associated isochoric heating. First, an integrated fast ignition experiment is carried out with 0.9 kJ of energy in the compression beam and 70 J in the ignition beam. Measurements of absolute K{sub {alpha}} yield from the imploded core revealed that about 17% of the laser energy is coupled to the suprathermal electrons. Modeling of the transport of these electrons and the associated isochoric heating, with the previously determined laser-to-electron conversion efficiency, showed a maximum target temperature of 166 eV at the front where the electron flux is higher and the density is lower. The contribution of the potential, induced by charge separation, in opposing the motion of the electrons was moderate. Second, temperature sensitivity of Cu K{sub {alpha}} imaging efficiency using a spherical Bragg reflecting crystal is investigated. It was found that due to the shifting and broadening of the K{sub {alpha}} line, with increasing temperature, both the brightness and the pattern of K{sub {alpha}} intensity are affected. Finally, x-ray spectroscopy of a 500 J 0.7 ps laser-solid interactions showed the formation of a hot surface layer({approx} 1 {micro}m) at the front of the target. PIC simulations confirm surface heating.

  7. Experimental investigation of piston heat transfer under conventional diesel and reactivity-controlled compression ignition combustion regimes

    SciTech Connect (OSTI)

    Splitter, Derek A [ORNL; Hendricks, Terry Lee [Sandia National Laboratories (SNL); Ghandhi, Jaal B [University of Wisconsin

    2014-01-01T23:59:59.000Z

    The piston of a heavy-duty single-cylinder research engine was instrumented with 11 fast-response surface thermocouples, and a commercial wireless telemetry system was used to transmit the signals from the moving piston. The raw thermocouple data were processed using an inverse heat conduction method that included Tikhonov regularization to recover transient heat flux. By applying symmetry, the data were compiled to provide time-resolved spatial maps of the piston heat flux and surface temperature. A detailed comparison was made between conventional diesel combustion and reactivity-controlled compression ignition combustion operations at matched conditions of load, speed, boost pressure, and combustion phasing. The integrated piston heat transfer was found to be 24% lower, and the mean surface temperature was 25 C lower for reactivity-controlled compression ignition operation as compared to conventional diesel combustion, in spite of the higher peak heat release rate. Lower integrated piston heat transfer for reactivity-controlled compression ignition was found over all the operating conditions tested. The results showed that increasing speed decreased the integrated heat transfer for conventional diesel combustion and reactivity-controlled compression ignition. The effect of the start of injection timing was found to strongly influence conventional diesel combustion heat flux, but had a negligible effect on reactivity-controlled compression ignition heat flux, even in the limit of near top dead center high-reactivity fuel injection timings. These results suggest that the role of the high-reactivity fuel injection does not significantly affect the thermal environment even though it is important for controlling the ignition timing and heat release rate shape. The integrated heat transfer and the dynamic surface heat flux were found to be insensitive to changes in boost pressure for both conventional diesel combustion and reactivity-controlled compression ignition. However, for reactivity-controlled compression ignition, the mean surface temperature increased with changes in boost suggesting that equivalence ratio affects steady-state heat transfer.

  8. Characterization of in situ oil shale retorts prior to ignition

    DOE Patents [OSTI]

    Turner, Thomas F. (Laramie, WY); Moore, Dennis F. (Laramie, WY)

    1984-01-01T23:59:59.000Z

    Method and system for characterizing a vertical modified in situ oil shale retort prior to ignition of the retort. The retort is formed by mining a void at the bottom of a proposed retort in an oil shale deposit. The deposit is then sequentially blasted into the void to form a plurality of layers of rubble. A plurality of units each including a tracer gas cannister are installed at the upper level of each rubble layer prior to blasting to form the next layer. Each of the units includes a receiver that is responsive to a coded electromagnetic (EM) signal to release gas from the associated cannister into the rubble. Coded EM signals are transmitted to the receivers to selectively release gas from the cannisters. The released gas flows through the retort to an outlet line connected to the floor of the retort. The time of arrival of the gas at a detector unit in the outlet line relative to the time of release of gas from the cannisters is monitored. This information enables the retort to be characterized prior to ignition.

  9. Radiological assessments for the National Ignition Facility

    SciTech Connect (OSTI)

    Hong, Kou-John; Lazaro, M.A.

    1996-08-01T23:59:59.000Z

    The potential radiological impacts of the National Ignition Facility (NIF), a proposed facility for fusion ignition and high energy density experiments, were assessed for five candidate sites to assist in site selection. The GENII computer program was used to model releases of radionuclides during normal NIF operations and a postulated accident and to calculate radiation doses to the public. Health risks were estimated by converting the estimated doses into health effects using a standard cancer fatality risk factor. The greatest calculated radiation dose was less than one thousandth of a percent of the dose received from natural background radiation; no cancer fatalities would be expected to occur in the public as the result of normal operations. The highest dose conservatively estimated to result from a postulated accident could lead to one in one million risk of cancer.

  10. Transport Simulations for Fast Ignition on NIF

    SciTech Connect (OSTI)

    Strozzi, D J; Tabak, M; Grote, D P; Cohen, B I; Shay, H D; Town, R J; Kemp, A J; Key, M

    2009-10-26T23:59:59.000Z

    We are designing a full hydro-scale cone-guided, indirect-drive FI coupling experiment, for NIF, with the ARC-FIDO short-pulse laser. Current rad-hydro designs with limited fuel jetting into cone tip are not yet adequate for ignition. Designs are improving. Electron beam transport simulations (implicit-PIC LSP) show: (1) Magnetic fields and smaller angular spreads increase coupling to ignition-relevant 'hot spot' (20 um radius); (2) Plastic CD (for a warm target) produces somewhat better coupling than pure D (cryogenic target) due to enhanced resistive B fields; and (3) The optimal T{sub hot} for this target is {approx} 1 MeV; coupling falls by 3x as T{sub hot} rises to 4 MeV.

  11. Stable transport in proton driven Fast Ignition

    E-Print Network [OSTI]

    Bret, A

    2009-01-01T23:59:59.000Z

    Proton beam transport in the context of proton driven Fast Ignition is usually assumed to be stable due to protons high inertia, but an analytical analysis of the process is still lacking. The stability of a charge and current neutralized proton beam passing through a plasma is therefore conducted here, for typical proton driven Fast Ignition parameters. In the cold regime, two fast growing Buneman-like modes are found, with an inverse growth-rate much smaller than the beam time-of-flight to the target core. The stability issue is thus not so obvious, and Kinetic effects are investigated. One unstable mode is found stabilized by the background plasma protons and electrons temperatures. The second mode is also damped, providing the proton beam thermal spread is larger than $\\sim$ 10 keV. In Fusion conditions, the beam propagation should therefore be stable.

  12. Ignition quality determination of marine diesel fuels

    SciTech Connect (OSTI)

    Gulder, O.L.; Glavincevski, B.; Kassinger, R.

    1987-01-01T23:59:59.000Z

    Ignition quality of heavy marine diesel fuels is considered to be an important parameter. The standard procedures used to quantify this parameter for distillate fuels are not applicable to residual fuels. Proton NMR Spectroscopy was demonstrated to be an effective tool to characterize the ''global'' fuel composition of commercially available fuels covering a wide range of ignition quality. Proton NMR data from these fuels were used to determine a cetane number (CNp) for the heavy fuels using procedures previously reported for distillate fuels. The validity of this instrumental technique for determining CNp was corroborated by actual ASTM D 613 engine tests on a number of commercially available fuels, run as blends with secondary reference fuels. Viscosity and density values of the analyzed heavy fuels were regressed against predicted cetane numbers to obtain a correlation expression.

  13. Multiple laser pulse ignition method and apparatus

    DOE Patents [OSTI]

    Early, James W. (Los Alamos, NM)

    1998-01-01T23:59:59.000Z

    Two or more laser light pulses with certain differing temporal lengths and peak pulse powers can be employed sequentially to regulate the rate and duration of laser energy delivery to fuel mixtures, thereby improving fuel ignition performance over a wide range of fuel parameters such as fuel/oxidizer ratios, fuel droplet size, number density and velocity within a fuel aerosol, and initial fuel temperatures.

  14. Low-pressure spark gap triggered by an ion diode

    DOE Patents [OSTI]

    Prono, D.S.

    1982-08-31T23:59:59.000Z

    Spark gap apparatus for use as an electric switch operating at high voltage, high current and high repetition rate. Mounted inside a housing are an anode, cathode and ion plate. An ionizable fluid is pumped through the chamber of the housing. A pulse of current to the ion plate causes ions to be emitted by the ion plate, which ions move into and ionize the fluid. Electric current supplied to the anode discharges through the ionized fluid and flows to the cathode. Current stops flowing when the current source has been drained. The ionized fluid recombines into its initial dielectric ionizable state. The switch is now open and ready for another cycle.

  15. Low pressure spark gap triggered by an ion diode

    DOE Patents [OSTI]

    Prono, Daniel S. (Livermore, CA)

    1985-01-01T23:59:59.000Z

    Spark gap apparatus for use as an electric switch operating at high voltage, high current and high repetition rate. Mounted inside a housing are an anode, cathode and ion plate. An ionizable fluid is pumped through the chamber of the housing. A pulse of current to the ion plate causes ions to be emitted by the ion plate, which ions move into and ionize the fluid. Electric current supplied to the anode discharges through the ionized fluid and flows to the cathode. Current stops flowing when the current source has been drained. The ionized fluid recombines into its initial dielectric ionizable state. The switch is now open and ready for another cycle.

  16. Spark Plasma Sintering of W-UO2 Cermets

    SciTech Connect (OSTI)

    R. C. O'Brien; N. D. Jerred

    2013-02-01T23:59:59.000Z

    About 50 vol.% 3 um depleted uranium dioxide (UO2) powder was encapsulated within a tungsten super alloy matrix produced from sub-micron tungsten powders using the Spark Plasma Sintering (SPS) process. An additive of 25 atom-percent (at.%) rhenium was included within the tungsten matrix to improve the ductility and fracture toughness of the ceramic–metallic (cermet) matrix. Cermet fabrication to 97.9% of the theoretical cermet density was achieved by sintering at 1500 degrees C with 40 MPa of applied pressure for 20 min. The results presented are from the first known trials of W–UO2 and nuclear cermet production via SPS.

  17. Spark Plasma Sintering of Fuel Cermets for Nuclear Reactor Applications

    SciTech Connect (OSTI)

    Yang Zhong; Robert C. O'Brien; Steven D. Howe; Nathan D. Jerred; Kristopher Schwinn; Laura Sudderth; Joshua Hundley

    2011-11-01T23:59:59.000Z

    The feasibility of the fabrication of tungsten based nuclear fuel cermets via Spark Plasma Sintering (SPS) is investigated in this work. CeO2 is used to simulate fuel loadings of UO2 or Mixed-Oxide (MOX) fuels within tungsten-based cermets due to the similar properties of these materials. This study shows that after a short time sintering, greater than 90 % density can be achieved, which is suitable to possess good strength as well as the ability to contain fission products. The mechanical properties and the densities of the samples are also investigated as functions of the applied pressures during the sintering.

  18. Spark Energy, LP (New York) | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualProperty Edit with formSoutheastern IL Elec Coop, IncSouthwesternSpark Energy, LPSpark Energy,

  19. Multi-zone modelling of partially premixed low-temperature combustion in pilot-ignited natural-gas engines

    SciTech Connect (OSTI)

    Krishnan, S. R.; Srinivasan, K. K.

    2010-06-29T23:59:59.000Z

    Detailed results from a multi-zone phenomenological simulation of partially premixed advanced-injection low-pilot-ignited natural-gas low-temperature combustion are presented with a focus on early injection timings (the beginning of (pilot) injection (BOI)) and very small diesel quantities (2-3 per cent of total fuel energy). Combining several aspects of diesel and spark ignition engine combustion models, the closed-cycle simulation accounted for diesel autoignition, diesel spray combustion, and natural-gas combustion by premixed turbulent flame propagation. The cylinder contents were divided into an unburned zone, several pilot fuel zones (or 'packets') that modelled diesel evaporation and ignition, a flame zone for natural-gas combustion, and a burned zone. The simulation predicted the onset of ignition, cylinder pressures, and heat release rate profiles satisfactorily over a wide range of BOIs (20-60���° before top dead centre (before TDC)) but especially well at early BOIs. Strong coupling was observed between pilot spray combustion in the packets and premixed turbulent combustion in the flame zone and, therefore, the number of ignition centres (packets) profoundly affected flame combustion. The highest local peak temperatures (greater than 2000 K) were observed in the packets, while the flame zone was much cooler (about 1650 K), indicating that pilot diesel spray combustion is probably the dominant source of engine-out emissions of nitrogen oxide (NO x). Further, the 60���° before TDC BOI yielded the lowest average peak packet temperatures (about 1720 K) compared with the 20���° before TDC BOI (about 2480 K) and 40���° before TDC BOI (about 2700 K). These trends support experimental NO x trends, which showed the lowest NO x emissions for the 60���°, 20���°, and 40���° before TDC BOIs in that order. Parametric studies showed that increasing the intake charge temperature, pilot quantity, and natural-gas equivalence ratio all led to higher peak heat release rates and hotter packets but the pilot quantity and intake temperature affected the potential for NO x formation to a greater extent.

  20. Electron Generation and Transport in Intense Relativistic Laser-Plasma Interactions Relevant to Fast Ignition ICF

    SciTech Connect (OSTI)

    Ma, T

    2010-04-21T23:59:59.000Z

    The reentrant cone approach to Fast Ignition, an advanced Inertial Confinement Fusion scheme, remains one of the most attractive because of the potential to efficiently collect and guide the laser light into the cone tip and direct energetic electrons into the high density core of the fuel. However, in the presence of a preformed plasma, the laser energy is largely absorbed before it can reach the cone tip. Full scale fast ignition laser systems are envisioned to have prepulses ranging between 100 mJ to 1 J. A few of the imperative issues facing fast ignition, then, are the conversion efficiency with which the laser light is converted to hot electrons, the subsequent transport characteristics of those electrons, and requirements for maximum allowable prepulse this may put on the laser system. This dissertation examines the laser-to-fast electron conversion efficiency scaling with prepulse for cone-guided fast ignition. Work in developing an extreme ultraviolet imager diagnostic for the temperature measurements of electron-heated targets, as well as the validation of the use of a thin wire for simultaneous determination of electron number density and electron temperature will be discussed.

  1. Full densification of Molybdenum powders using Spark Plasma Sintering B. Mouawad1

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Full densification of Molybdenum powders using Spark Plasma Sintering B. Mouawad1 , M. Soueidan1, 2.bley@laplace.univ-tlse.fr, bruno.allard@insa- lyon.fr Abstract: Pure molybdenum powder was sintered using Spark Plasma Sintering Plasma Sintering, densification, microstructure. I. Introduction Molybdenum has a body-centered cubic

  2. Size effects on varistor properties made from zinc oxide nanoparticles by low temperature spark plasma sintering

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    of nanostructured varistors by Spark Plasma Sintering (SPS) are investigated, using 8 nm zinc oxide nanoparticles to 600°C. Keywords: Organometallic, Zinc oxide, Nanoparticles, Spark plasma sintering, Varistor hal plasma sintering By Léna Saint Macary, § Myrtil L. Kahn, * Claude Estournčs; Pierre Fau , David

  3. SUBMISSION TO IEEE TRANSACTIONS ON COMPONENTS AND PACKAGING TECHNOLOGIES 1 Application of the Spark Plasma Sintering

    E-Print Network [OSTI]

    Boyer, Edmond

    --semiconductor device packaging, power elec- tronics, Spark Plasma Sintering, Three-dimensional packaging. I Plasma Sintering Technique to Low-Temperature Copper Bonding Bassem Mouawad, Maher Soueidan, Damien FabrSUBMISSION TO IEEE TRANSACTIONS ON COMPONENTS AND PACKAGING TECHNOLOGIES 1 Application of the Spark

  4. Method and apparatus for electrical cable testing by pulse-arrested spark discharge

    DOE Patents [OSTI]

    Barnum, John R. (Albuquerque, NM); Warne, Larry K. (Albuquerque, NM); Jorgenson, Roy E. (Albuquerque, NM); Schneider, Larry X. (Albuquerque, NM)

    2005-02-08T23:59:59.000Z

    A method for electrical cable testing by Pulse-Arrested Spark Discharge (PASD) uses the cable response to a short-duration high-voltage incident pulse to determine the location of an electrical breakdown that occurs at a defect site in the cable. The apparatus for cable testing by PASD includes a pulser for generating the short-duration high-voltage incident pulse, at least one diagnostic sensor to detect the incident pulse and the breakdown-induced reflected and/or transmitted pulses propagating from the electrical breakdown at the defect site, and a transient recorder to record the cable response. The method and apparatus are particularly useful to determine the location of defect sites in critical but inaccessible electrical cabling systems in aging aircraft, ships, nuclear power plants, and industrial complexes.

  5. Status and Prospects of the Fast Ignition Inertial Fusion Concept

    SciTech Connect (OSTI)

    Key, M H

    2006-11-15T23:59:59.000Z

    Fast ignition is an alternate concept in inertial confinement fusion, which has the potential for easier ignition and greater energy multiplication. If realized it could improve the prospects for inertial fusion energy. It poses stimulating challenges in science and technology and the research is approaching a key stage in which the feasibility of fast ignition will be determined. This review covers the concepts, the state of the science and technology, the near term prospects and the challenges and risks involved in demonstrating high gain fast ignition.

  6. Microwave-Assisted Ignition for Improved Internal Combustion Engine Efficiency

    E-Print Network [OSTI]

    DeFilippo, Anthony Cesar

    2013-01-01T23:59:59.000Z

    J. B. (1988) Internal Combustion Engine Fundamentals.novel microwave internal combustion engine ignition source,in the Internal Combustion Engine." SAE Technical Paper

  7. Microwave-Assisted Ignition for Improved Internal Combustion Engine Efficiency

    E-Print Network [OSTI]

    DeFilippo, Anthony Cesar

    2013-01-01T23:59:59.000Z

    Modeling of Emissions from HCCI Engines using a ConsistentMechanism for Iso-Octane HCCI Combustion With TargetedCharge Compression Ignition (HCCI) Engine: Experimental and

  8. LES of an ignition sequence in a gas turbine M. Boileau a,, G. Staffelbach a

    E-Print Network [OSTI]

    injection. Finally, a variability of the combustor sectors and quadrants ignition times is highlighted combustion in a 18-burner combustor. · II - Flame ignition: the hot gases produced by the igniter must

  9. Modeling the Fuel Spray and Combustion Process of the Ignition Quality Tester with KIVA-3V

    SciTech Connect (OSTI)

    Bogin, G. E. Jr.; DeFilippo, A.; Chen, J. Y.; Chin, G.; Luecke, J.; Ratcliff, M. A.; Zigler, B. T.; Dean, A. M.

    2010-05-01T23:59:59.000Z

    Discusses the use of KIVA-3V to develop a model that reproduces ignition behavior inside the Ignition Quality Tester, which measures the ignition delay of low-volatility fuels.

  10. Laser propagation and energy absorption by an argon spark C. V. Bindhu, S. S. Harilal,a)

    E-Print Network [OSTI]

    Tillack, Mark

    Laser propagation and energy absorption by an argon spark C. V. Bindhu, S. S. Harilal,a) M. S The laser propagation and energy absorption of an argon spark induced by a laser at different pressures is investigated. 8 ns pulses from a frequency-doubled Q-switched Nd:YAG laser are used to create the spark

  11. Magnetic enhancement of thermal conductivity in coppercarbon nanotube composites produced by electroless plating, freeze drying, and spark plasma sintering

    E-Print Network [OSTI]

    Meyers, Marc A.

    by electroless plating, freeze drying, and spark plasma sintering Evan Khaleghi a, , Milton Torikachvili b , Marc Available online 9 April 2012 Keywords: Magnetic Carbon nanotube Spark plasma sintering Thermal conductivity and freeze-drying for green processing, and spark plasma sintering for densification. A magnetic field of 1

  12. Optical key system

    DOE Patents [OSTI]

    Hagans, Karla G. (Livermore, CA); Clough, Robert E. (Danville, CA)

    2000-01-01T23:59:59.000Z

    An optical key system comprises a battery-operated optical key and an isolated lock that derives both its operating power and unlock signals from the correct optical key. A light emitting diode or laser diode is included within the optical key and is connected to transmit a bit-serial password. The key user physically enters either the code-to-transmit directly, or an index to a pseudorandom number code, in the key. Such person identification numbers can be retained permanently, or ephemeral. When a send button is pressed, the key transmits a beam of light modulated with the password information. The modulated beam of light is received by a corresponding optical lock with a photovoltaic cell that produces enough power from the beam of light to operate a password-screen digital logic. In one application, an acceptable password allows a two watt power laser diode to pump ignition and timing information over a fiberoptic cable into a sealed engine compartment. The receipt of a good password allows the fuel pump, spark, and starter systems to each operate. Therefore, bypassing the lock mechanism as is now routine with automobile thieves is pointless because the engine is so thoroughly disabled.

  13. The National Ignition Facility and the Promise of Inertial Fusion Energy

    SciTech Connect (OSTI)

    Moses, E I

    2010-12-13T23:59:59.000Z

    The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory (LLNL) in Livermore, CA, is now operational. The NIF is the world's most energetic laser system capable of producing 1.8 MJ and 500 TW of ultraviolet light. By concentrating the energy from its 192 extremely energetic laser beams into a mm{sup 3}-sized target, NIF can produce temperatures above 100 million K, densities of 1,000 g/cm{sup 3}, and pressures 100 billion times atmospheric pressure - conditions that have never been created in a laboratory and emulate those in planetary interiors and stellar environments. On September 29, 2010, the first integrated ignition experiment was conducted, demonstrating the successful coordination of the laser, cryogenic target system, array of diagnostics and infrastructure required for ignition demonstration. In light of this strong progress, the U.S. and international communities are examining the implication of NIF ignition for inertial fusion energy (IFE). A laser-based IFE power plant will require a repetition rate of 10-20 Hz and a laser with 10% electrical-optical efficiency, as well as further development and advances in large-scale target fabrication, target injection, and other supporting technologies. These capabilities could lead to a prototype IFE demonstration plant in the 10- to 15-year time frame. LLNL, in partnership with other institutions, is developing a Laser Inertial Fusion Engine (LIFE) concept and examining in detail various technology choices, as well as the advantages of both pure fusion and fusion-fission schemes. This paper will describe the unprecedented experimental capabilities of the NIF and the results achieved so far on the path toward ignition. The paper will conclude with a discussion about the need to build on the progress on NIF to develop an implementable and effective plan to achieve the promise of LIFE as a source of carbon-free energy.

  14. Ignition of hydrogen/air mixing layer in turbulent flows

    SciTech Connect (OSTI)

    Im, H.G.; Chen, J.H. [Sandia National Labs., Livermore, CA (United States). Combustion Research Facility; Law, C.K. [Princeton Univ., NJ (United States). Dept. of Mechanical and Aerospace Engineering

    1998-03-01T23:59:59.000Z

    Autoignition of a scalar hydrogen/air mixing layer in homogeneous turbulence is studied using direct numerical simulation. An initial counterflow of unmixed nitrogen-diluted hydrogen and heated air is perturbed by two-dimensional homogeneous turbulence. The temperature of the heated air stream is chosen to be 1,100 K which is substantially higher than the crossover temperature at which the rates of the chain branching and termination reactions become equal. Three different turbulence intensities are tested in order to assess the effect of the characteristic flow time on the ignition delay. For each condition, a simulation without heat release is also performed. The ignition delay determined with and without heat release is shown to be almost identical up to the point of ignition for all of the turbulence intensities tested, and the predicted ignition delays agree well within a consistent error band. It is also observed that the ignition kernel always occurs where hydrogen is focused, and the peak concentration of HO{sub 2} is aligned well with the scalar dissipation rate. The dependence of the ignition delay on turbulence intensity is found to be nonmonotonic. For weak to moderate turbulence the ignition is facilitated by turbulence via enhanced mixing, while for stronger turbulence, whose timescale is substantially smaller than the ignition delay, the ignition is retarded due to excessive scalar dissipation, and hence diffusive loss, at the ignition location. However, for the wide range of initial turbulence fields studied, the variation in ignition delay due to the corresponding variation in turbulence intensity appears to be quite small.

  15. M. Bahrami ENSC 461 (S 11) IC Engines 1 Air Standard Assumptions

    E-Print Network [OSTI]

    Bahrami, Majid

    is provided by burning fuel within the system boundaries, i.e., internal combustion engines. The following. Internal Combustion Engines 1. spark ignition engines: a mixture of fuel and air is ignited by a spark in (ideal) power cycles are internally reversible. 3- Combustion process is modeled by a heat

  16. Quantifying the Effects of Idle-Stop Systems on Fuel Economy in Light-Duty Passenger Vehicles

    SciTech Connect (OSTI)

    Jeff Wishart; Matthew Shirk

    2012-12-01T23:59:59.000Z

    Vehicles equipped with idle-stop (IS) systems are capable of engine shut down when the vehicle is stopped and rapid engine re-start for the vehicle launch. This capability reduces fuel consumption and emissions during periods when the engine is not being utilized to provide propulsion or to power accessories. IS systems are a low-cost and fast-growing technology in the industry-wide pursuit of increased vehicle efficiency, possibly becoming standard features in European vehicles in the near future. In contrast, currently there are only three non-hybrid vehicle models for sale in North America with IS systems and these models are distinctly low-volume models. As part of the United States Department of Energy’s Advanced Vehicle Testing Activity, ECOtality North America has tested the real-world effect of IS systems on fuel consumption in three vehicle models imported from Europe. These vehicles were chosen to represent three types of systems: (1) spark ignition with 12-V belt alternator starter; (2) compression ignition with 12-V belt alternator starter; and (3) direct-injection spark ignition, with 12-V belt alternator starter/combustion restart. The vehicles have undergone both dynamometer and on-road testing; the test results show somewhat conflicting data. The laboratory data and the portion of the on-road data in which driving is conducted on a prescribed route with trained drivers produced significant fuel economy improvement. However, the fleet data do not corroborate improvement, even though the data show significant engine-off time. It is possible that the effects of the varying driving styles and routes in the fleet testing overshadowed the fuel economy improvements. More testing with the same driver over routes that are similar with the IS system-enabled and disabled is recommended. There is anecdotal evidence that current Environmental Protection Agency fuel economy test procedures do not capture the fuel economy gains that IS systems produce in real-world driving. The program test results provide information on the veracity of these claims.

  17. Low emissions compression ignited engine technology

    DOE Patents [OSTI]

    Coleman, Gerald N. (Dunlap, IL); Kilkenny, Jonathan P. (Peoria, IL); Fluga, Eric C. (Dunlap, IL); Duffy, Kevin P. (East Peoria, IL)

    2007-04-03T23:59:59.000Z

    A method and apparatus for operating a compression ignition engine having a cylinder wall, a piston, and a head defining a combustion chamber. The method and apparatus includes delivering fuel substantially uniformly into the combustion chamber, the fuel being dispersed throughout the combustion chamber and spaced from the cylinder wall, delivering an oxidant into the combustion chamber sufficient to support combustion at a first predetermined combustion duration, and delivering a diluent into the combustion chamber sufficient to change the first predetermined combustion duration to a second predetermined combustion duration different from the first predetermined combustion duration.

  18. Ignite High Tech Startups | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are8COaBulkTransmissionSitingProcess.pdfGetecGtel JumpCounty, Texas:ITCSolidIdaho‎ |Idylwood, Virginia: EnergyIgnite

  19. Recent progress on the Compact Ignition Tokamak (CIT)

    SciTech Connect (OSTI)

    Ignat, D.W.

    1987-01-01T23:59:59.000Z

    This report describes work done on the Compact Ignition Tokamak (CIT), both at the Princeton Plasma Physics Laboratory (PPPL) and at other fusion laboratories in the United States. The goal of CIT is to reach ignition in a tokamak fusion device in the mid-1990's. Scientific and engineering features of the design are described, as well as projected cost and schedule.

  20. Homogeneous Charge Compression Ignition: Formulation Effect of a Diesel Fuel

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Homogeneous Charge Compression Ignition: Formulation Effect of a Diesel Fuel on the Initiation and the Combustion Potential of Olefin Impact in a Diesel Base Fuel D. Alseda1,2, X. Montagne1 and P. Dagaut2 1 Compression Ignition: Formulation Effect of a Diesel Fuel on the Initiation and the Combustion - Potential

  1. Advantages of Oxygenates Fuels over Gasoline in Direct Injection Spark

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny: The Future of1 AAcceleratedDepartmentDepartment2 DOEX-RayDepartmentIgnition

  2. Variable valve timing in a homogenous charge compression ignition engine

    DOE Patents [OSTI]

    Lawrence, Keith E.; Faletti, James J.; Funke, Steven J.; Maloney, Ronald P.

    2004-08-03T23:59:59.000Z

    The present invention relates generally to the field of homogenous charge compression ignition engines, in which fuel is injected when the cylinder piston is relatively close to the bottom dead center position for its compression stroke. The fuel mixes with air in the cylinder during the compression stroke to create a relatively lean homogeneous mixture that preferably ignites when the piston is relatively close to the top dead center position. However, if the ignition event occurs either earlier or later than desired, lowered performance, engine misfire, or even engine damage, can result. The present invention utilizes internal exhaust gas recirculation and/or compression ratio control to control the timing of ignition events and combustion duration in homogeneous charge compression ignition engines. Thus, at least one electro-hydraulic assist actuator is provided that is capable of mechanically engaging at least one cam actuated intake and/or exhaust valve.

  3. Manifestation of constrained dynamics in a low pressure spark

    E-Print Network [OSTI]

    Auluck, S K H

    2013-01-01T23:59:59.000Z

    Some features of neutron emission from dense plasma focus suggest that the participating deuterons have energy in the range of 105 eV and have a directionality of toroidal motion. Theoretical models of these devices assume that the plasma evolves through a purely irrotational flow and thus fail to predict such solenoidal flow on the scale of the plasma dimensions. Predictions of a relaxation theory are consistent with experimental data [S K H Auluck, Physics of Plasmas,18, 032508 (2011)], but the assumptions upon which it is based are not compatible with known features of these devices. There is thus no satisfactory theoretical construct which provides the necessity for solenoidal flow in these devices. This paper proposes such theoretical construct, namely, the principle of constrained dynamics, and describes an experiment which provides support for this idea. The experiment consisted of low inductance, self-breaking spark discharge in helium at a pressure ~100 hPa between two pointed electrodes separated by...

  4. National Ignition Facility project acquisition plan

    SciTech Connect (OSTI)

    Callaghan, R.W.

    1996-04-01T23:59:59.000Z

    The purpose of this National Ignition Facility Acquisition Plan is to describe the overall procurement strategy planned for the National Ignition Facility (NIF) Project. The scope of the plan describes the procurement activities and acquisition strategy for the following phases of the NIF Project, each of which receives either plant and capital equipment (PACE) or other project cost (OPC) funds: Title 1 and 2 design and Title 3 engineering (PACE); Optics manufacturing facilitization and pilot production (OPC); Convention facility construction (PACE); Procurement, installation, and acceptance testing of equipment (PACE); and Start-up (OPC). Activities that are part of the base Inertial Confinement Fusion (ICF) Program are not included in this plan. The University of California (UC), operating Lawrence Livermore National Laboratory (LLNL) and Los Alamos National Laboratory, and Lockheed-Martin, which operates Sandia National Laboratory (SNL) and the University of Rochester Laboratory for Laser Energetics (UR-LLE), will conduct the acquisition of needed products and services in support of their assigned responsibilities within the NIF Project structure in accordance with their prime contracts with the Department of Energy (DOE). LLNL, designated as the lead Laboratory, will have responsibility for all procurements required for construction, installation, activation, and startup of the NIF.

  5. National Ignition Facility and Managing Location, Component, and State

    SciTech Connect (OSTI)

    Foxworthy, C; Fung, T; Beeler, R; Li, J; Dugorepec, J; Chang, C

    2011-07-25T23:59:59.000Z

    The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory is a stadium-sized facility that contains a 192-beam, 1.8-Megajoule, 500-Terawatt, ultraviolet laser system coupled with a 10-meter diameter target chamber. There are over 6,200 Line Replaceable Units (LRUs) comprised of more than 104,000 serialized parts that make up the NIF. Each LRU is a modular unit typically composed of a mechanical housing, laser optics (glass, lenses, or mirrors), and utilities. To date, there are more than 120,000 data sets created to characterize the attributes of these parts. Greater than 51,000 Work Permits have been issued to install, maintain, and troubleshoot the components. One integrated system is used to manage these data, and more. The Location Component and State (LoCoS) system is a web application built using Java Enterprise Edition technologies and is accessed by over 1,200 users. It is either directly or indirectly involved with each aspect of NIF work activity, and interfaces with ten external systems including the Integrated Computer Control System (ICCS) and the Laser Performance Operations Model (LPOM). Besides providing business functionality, LoCoS also acts as the NIF enterprise service bus. In this role, numerous integration approaches had to be adopted including: file exchange, database sharing, queuing, and web services in order to accommodate various business, technical, and security requirements. Architecture and implementation decisions are discussed.

  6. Group pyrolysis, ignition, and combustion of a spherical cloud of coal particles

    E-Print Network [OSTI]

    Ryan, William Richard

    1988-01-01T23:59:59.000Z

    , and combustion of pulverized coal. Finally, the relevance of group combustion studies to practical systems is discussed. 2. 1. Grou Combustion and Terminolo Group combustion implies the formation of a common flame around a large number of drops... of the processes involved in practical burners, these studies are useful in the prevention of dust cloud explosions. The experimental apparatus and conditions for conducting pulverized coal ignition studies are described briefly: (1. ) Transport Reactors...

  7. Catalytic igniters and their use to ignite lean hydrogen-air mixtures

    DOE Patents [OSTI]

    McLean, William J. (Oakland, CA); Thorne, Lawrence R. (Livermore, CA); Volponi, Joanne V. (Livermore, CA)

    1988-01-01T23:59:59.000Z

    A catalytic igniter which can ignite a hydrogen-air mixture as lean as 5.5% hydrogen with induction times ranging from 20 s to 400 s, under conditions which may be present during a loss-of-liquid-coolant accident at a light water nuclear reactor comprises (a) a perforate catalytically active substrate, such as a platinum coated ceramic honeycomb or wire mesh screen, through which heated gases produced by oxidation of the mixture can freely flow and (b) a plurality of thin platinum wires mounted in a thermally conductive manner on the substrate and positioned thereon so as to be able to receive heat from the substrate and the heated gases while also in contact with unoxidized gases.

  8. Pre-ignition laser ablation of nanocomposite energetic materials

    SciTech Connect (OSTI)

    Stacy, S. C.; Massad, R. A.; Pantoya, M. L. [Department of Mechanical Engineering, Texas Tech University, Lubbock, Texas 79409 (United States)] [Department of Mechanical Engineering, Texas Tech University, Lubbock, Texas 79409 (United States)

    2013-06-07T23:59:59.000Z

    Laser ignition of energetic material composites was studied for initiation with heating rates from 9.5 Multiplication-Sign 10{sup 4} to 1.7 Multiplication-Sign 10{sup 7} K/s. This is a unique heating rate regime for laser ignition studies because most studies employ either continuous wave CO{sub 2} lasers to provide thermal ignition or pulsed Nd:YAG lasers to provide shock ignition. In this study, aluminum (Al) and molybdenum trioxide (MoO{sub 3}) nanoparticle powders were pressed into consolidated pellets and ignited using a Nd:YAG laser (1064 nm wavelength) with varied pulse energy. Results show reduced ignition delay times corresponding to laser powers at the ablation threshold for the sample. Heating rate and absorption coefficient were determined from an axisymmetric heat transfer model. The model estimates absorption coefficients from 0.1 to 0.15 for consolidated pellets of Al + MoO{sub 3} at 1064 nm wavelength. Ablation resulted from fracturing caused by a rapid increase in thermal stress and slowed ignition of the pellet.

  9. Dynamic Modeling of Combustion and Gas Exchange Processes for Controlled Auto-Ignition Engines

    E-Print Network [OSTI]

    Cambridge, University of

    ), also known as Homo- geneous Charge Compression Ignition (HCCI) has been receiving increased attention

  10. Cavitation-induced ignition of cryogenic hydrogen-oxygen fluids V. V. Osipov,1,a

    E-Print Network [OSTI]

    Muratov, Cyrill

    Cavitation-induced ignition of cryogenic hydrogen-oxygen fluids V. V. Osipov,1,a C. B. Muratov,2 E-ignite in the process of their sudden mixing. Here, we propose a cavitation-induced self-ignition mechanism that may a cavitation-induced self- ignition mechanism of cryogenic H2/Ox fluids. Cavitation is the formation

  11. Interaction of a spark-generated bubble with a rubber beam: Numerical and experimental study

    E-Print Network [OSTI]

    Gong, S. W.

    In this paper, the physical behaviors of the interaction between a spark-generated bubble and a rubber beam are studied. Both numerical and experimental approaches are employed to investigate the bubble collapse near the ...

  12. Apparatus and method for the spectrochemical analysis of liquids using the laser spark

    DOE Patents [OSTI]

    Cremers, David A. (Los Alamos, NM); Radziemski, Leon J. (Las Cruces, NM); Loree, Thomas R. (Los Alamos, NM)

    1990-01-01T23:59:59.000Z

    A method and apparatus for the qualitative and quantitative spectroscopic investigation of elements present in a liquid sample using the laser spark. A series of temporally closely spaced spark pairs is induced in the liquid sample utilizing pulsed electromagnetic radiation from a pair of lasers. The light pulses are not significantly absorbed by the sample so that the sparks occur inside of the liquid. The emitted light from the breakdown events is spectrally and temporally resolved, and the time period between the two laser pulses in each spark pair is adjusted to maximize the signal-to-noise ratio of the emitted signals. In comparison with the single pulse technique, a substantial reduction in the limits of detectability for many elements has been demonstrated. Narrowing of spectral features results in improved discrimination against interfering species.

  13. Apparatus and method for the spectrochemical analysis of liquids using the laser spark

    DOE Patents [OSTI]

    Cremers, D.A.; Radziemski, L.J.; Loree, T.R.

    1984-05-01T23:59:59.000Z

    A method and apparatus are disclosed for the qualitative and quantitative spectroscopic investigation of elements present in a liquid sample using the laser spark. A series of temporally closely spaced spark pairs is induced in the liquid sample utilizing pulsed electromagnetic radiation from a pair of lasers. The light pulses are not significantly absorbed by the sample so that the sparks occur inside of the liquid. The emitted light from the breakdown events is spectrally and temporally resolved, and the time period between the two laser pulses in each spark pair is adjusted to maximize the signal-to-noise ratio of the emitted signals. In comparison with the single pulse technique, a substantial reduction in the limits of detectability for many elements has been demonstrated. Narrowing of spectral features results in improved discrimination against interfering species.

  14. Impact of retarded spark timing on engine combustion, hydrocarbon emissions, and fast catalyst light-off

    E-Print Network [OSTI]

    Hallgren, Brian E. (Brian Eric), 1976-

    2005-01-01T23:59:59.000Z

    An experimental study was performed to determine the effects of substantial spark retard on engine combustion, hydrocarbon (HC) emissions, feed gas enthalpy, and catalyst light-off. Engine experiments were conducted at ...

  15. Fast Camera Imaging of Hall Thruster Ignition

    SciTech Connect (OSTI)

    C.L. Ellison, Y. Raitses and N.J. Fisch

    2011-02-24T23:59:59.000Z

    Hall thrusters provide efficient space propulsion by electrostatic acceleration of ions. Rotating electron clouds in the thruster overcome the space charge limitations of other methods. Images of the thruster startup, taken with a fast camera, reveal a bright ionization period which settles into steady state operation over 50 ?s. The cathode introduces azimuthal asymmetry, which persists for about 30 ?s into the ignition. Plasma thrusters are used on satellites for repositioning, orbit correction and drag compensation. The advantage of plasma thrusters over conventional chemical thrusters is that the exhaust energies are not limited by chemical energy to about an electron volt. For xenon Hall thrusters, the ion exhaust velocity can be 15-20 km/s, compared to 5 km/s for a typical chemical thruster

  16. Utility of the US National Ignition Facility for development of inertial fusion energy

    SciTech Connect (OSTI)

    Logan, B.G.; Anderson, A.T.; Tobin, M.T. [Lawrence Livermore National Lab., CA (United States); Schrock, V.E. [California Univ., Berkeley, CA (United States); Meier, W.R. [Schafer (W.J.) Associates, Inc., Livermore, CA (United States); Bangerter, R.O. [Lawrence Berkeley Lab., CA (United States); Tokheim, R.E. [SRI International, Menlo Park, CA (United States). Poulter Lab.; Abdou, M.A. [California Univ., Los Angeles, CA (United States); Schultz, K.R. [General Atomics, San Diego, CA (United States)

    1994-08-01T23:59:59.000Z

    The demonstration of inertial fusion ignition and gain in the proposed US National Ignition Facility (NIF), along with the parallel demonstration of the feasibility of an efficient, high-repetition-rate driver, would provide the basis for a follow-on Engineering Test Facility (ETF), a facility for integrated testing of the technologies needed for inertial fusion-energy (IFE) power plants. A workshop was convened at the University of California, Berkeley on February 22--24, 1994, attended by 61 participants from 17 US organizations, to identify possible NIF experiments relevant to IFE. We considered experiments in four IFE areas: Target physics, target chamber dynamics, fusion power ethnology, and target systems, as defined in the following sections.

  17. Solid debris collection for radiochemical diagnostics at the National Ignition Facility

    SciTech Connect (OSTI)

    Gostic, J. M.; Shaughnessy, D. A.; Moore, K. T.; Hutcheon, I. D.; Grant, P. M.; Moody, K. J. [Lawrence Livermore National Laboratory, 7000 East Ave, Livermore, California 94550 (United States)

    2012-10-15T23:59:59.000Z

    Radiochemical analysis of post-ignition debris inside the National Ignition Facility (NIF) target chamber can help determine various diagnostic parameters associated with the implosion efficiency of the fusion capsule. This technique is limited by the ability to distinguish ablator material from other debris and by the collection efficiency of the capsule debris after implosion. Prior to designing an on-line collection system, the chemical nature and distribution of the debris inside the chamber must be determined. The focus of our current work has been on evaluating capture of activated Au hohlraum debris on passive foils (5 cm diameter, 50 cm from target center) post-shot. Preliminary data suggest that debris distribution is locally heterogeneous along the equatorial and polar line-of-sights.

  18. Interim report on the assessment of engineering issues for compact high-field ignition devices

    SciTech Connect (OSTI)

    Flanagan, C.A. (ed.)

    1986-04-01T23:59:59.000Z

    The engineering issues addressed at the workshop included the overall configuration, layout, and assembly; limiter and first-wall energy removal; magnet system structure design; fabricability; repairability; and costs. In performing the assessment, the primary features and characteristics of each concept under study were reviewed as representative of this class of ignition device. The emphasis was to understand the key engineering areas of concern for this class of device and deliberately not attempt to define an optimum design or to choose a best approach. The assessment concluded that compact ignition tokamaks, as represented by the three concepts under study, are feasible. A number of critical engineering issues were identified, and all appear to have tractable solutions. The engineering issues appear quite challenging, and to obtain increased confidence in the apparent design solutions requires completion of the next level of design detail, complemented by appropriate development programs and testing.

  19. High voltage ignition of high pressure microwave powered UV light sources

    SciTech Connect (OSTI)

    Frank, J.D.; Cekic, M.; Wood, C.H. [Fusion U.V. Curing Systems Corp., Gaithersburg, MD (United States)

    1997-12-31T23:59:59.000Z

    Industrial microwave powered (electrodeless) light sources have been limited to quiescent pressures of {approximately}300 Torr of buffer gas and metal-halide fills. The predominant reason for such restrictions has been the inability to microwave ignite the plasma due to the collisionality of higher pressure fills and/or the electronegativity of halide bulb chemistries. Commercially interesting bulb fills require electric fields for ionization that are often large multiples of the breakdown voltage for air. Many auxiliary ignition methods are evaluated for efficiency and practicality before the choice of a high-voltage system with a retractable external electrode. The scheme utilizes a high voltage pulse power supply and a novel field emission source. Acting together they create localized condition of pressure reduction and high free electron density. This allows the normal microwave fields to drive this small region into avalanche, ignite the bulb, and heat the plasma to its operating point (T{sub e} {approx} 0.5 eV). This process is currently being used in a new generation of lamps, which are using multi-atmospheric excimer laser chemistries and pressure and constituent enhanced metal-halide systems. At the present time, production prototypes produce over 900 W of radiation in a 30 nm band, centered at 308 nm. Similarly, these prototypes when loaded with metal-halide bulb fills produce over 1 kW of radiation in 30 nm wide bands, centered about the wavelength of interest.

  20. Frictionally induced ignition processes in drop and skid tests

    SciTech Connect (OSTI)

    Dickson, Peter [Los Alamos National Laboratory; Parker, Gary [Los Alamos National Laboratory; Novak, Alan [Los Alamos National Laboratory

    2010-01-01T23:59:59.000Z

    The standard LANL/Pantex drop and skid tests rely on subjective assessment of reaction violence to quantify the response of the charge, and completely miss nonpropagating hot-spot ignition sites. Additionally, large variations in test results have been observed, which we propose is due to a misunderstanding of the basic physical processes that lead to threshold ignition in these tests. The tests have been redesigned to provide control of these mechanisms and to permit direct observation of hot spots at the impact site, allowing us to follow the progression of the outcome as the drop height and ignition source density are varied. The results confirm that frictional interactions between high-melting-point solids are the dominant ignition mechanism, not just at the threshold, but in fact at all realistic drop heights.

  1. Relativistic electron beam transport for fast ignition relevant scenarios

    E-Print Network [OSTI]

    Cottrill, Larissa A

    2009-01-01T23:59:59.000Z

    A crucial issue surrounding the feasibility of fast ignition, an alternative inertial confinement fusion scheme, is the ability to efficiently couple energy from an incident short-pulse laser to a high-density, pre-compressed ...

  2. Ignition technique for an in situ oil shale retort

    DOE Patents [OSTI]

    Cha, Chang Y. (Golden, CO)

    1983-01-01T23:59:59.000Z

    A generally flat combustion zone is formed across the entire horizontal cross-section of a fragmented permeable mass of formation particles formed in an in situ oil shale retort. The flat combustion zone is formed by either sequentially igniting regions of the surface of the fragmented permeable mass at successively lower elevations or by igniting the entire surface of the fragmented permeable mass and controlling the rate of advance of various portions of the combustion zone.

  3. Advantages of Oxygenates Fuels over Gasoline in Direct Injection...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Advantages of Oxygenates Fuels over Gasoline in Direct Injection Spark Ignition Engines Advantages of Oxygenates Fuels over Gasoline in Direct Injection Spark Ignition Engines...

  4. Assessing the prospects for achieving double-shell ignition on the National Ignition Facility using vacuum hohlraums

    SciTech Connect (OSTI)

    Amendt, Peter; Cerjan, C.; Hamza, A.; Hinkel, D. E.; Milovich, J. L.; Robey, H. F. [Lawrence Livermore National Laboratory, University of California, Livermore, California 94551 (United States)

    2007-05-15T23:59:59.000Z

    The goal of demonstrating ignition on the National Ignition Facility [J. D. Lindl et al., Phys. Plasmas 11, 339 (2003)] has motivated a revisit of double-shell (DS) targets as a complementary path to the cryogenic baseline approach. Expected benefits of DS ignition targets include noncryogenic deuterium-tritium (DT) fuel preparation, minimal hohlraum-plasma-mediated laser backscatter, low threshold-ignition temperatures ({approx_equal}4 keV) for relaxed hohlraum x-ray flux asymmetry tolerances, and minimal (two-) shock timing requirements. On the other hand, DS ignition presents several formidable challenges, encompassing room-temperature containment of high-pressure DT ({approx_equal}790 atm) in the inner shell, strict concentricity requirements on the two shells (<3 {mu}m), development of nanoporous (<100 nm cell size) low-density (<100 mg/cc) metallic foams for structural support of the inner shell and hydrodynamic instability mitigation, and effective control of hydrodynamic instabilities on the high-Atwood-number interface between the DT fuel and the high-Z inner shell. Recent progress in DS ignition designs and required materials science advances at the nanoscale are described herein. Two new ignition designs that use rugby-shaped vacuum hohlraums are presented that utilize either 1 or 2 MJ of laser energy at 3{omega}. The capability of the National Ignition Facility to generate the requested 2 MJ reverse-ramp pulse shape for DS ignition is expected to be comparable to the planned high-contrast ({approx_equal}100) pulse shape at 1.8 MJ for the baseline cryogenic target. Nanocrystalline, high-strength, Au-Cu alloy inner shells are under development using electrochemical deposition over a glass mandrel, exhibiting tensile strengths well in excess of 790 atm. Novel, low-density (85 mg/cc) copper foams have recently been demonstrated using 10 mg/cc SiO{sub 2} nanoporous aerogels with suspended Cu particles. A prototype demonstration of an ignition DS is planned for 2008, incorporating the needed novel nanomaterials science developments and the required fabrication tolerances for a realistic ignition attempt after 2010.

  5. The development of laser ignited deflagration-to-detonation transition (DDT) detonators and pyrotechnic actuators

    SciTech Connect (OSTI)

    Merson, J.A.; Salas, F.J.

    1994-05-01T23:59:59.000Z

    The use of laser ignited explosive components has been recognized as a safety enhancement over existing electrical explosive devices (EEDs). Sandia has been pursuing the development of optical ordnance for many years with recent emphasis on developing optical deflagration-to-detonation (DDT) detonators and pyrotechnic actuators. These low energy optical ordnance devices can be ignited with either a semiconductor diode laser, laser diode arrays or a solid state rod laser. By using a semiconductor laser diode, the safety improvement can be made without sacrificing performance since the input energy required for the laser diode and the explosive output are similar to existing electrical systems. The use of higher powered laser diode arrays or rod lasers may have advantages in fast DDT applications or lossy optical environments such as long fiber applications and applications with numerous optical connectors. Recent results from our continued study of optical ignition of explosive and pyrotechnic materials are presented. These areas of investigation can be separated into three different margin categories: (1) the margin relative to intended inputs ( i.e. powder performance as a function of laser input variation), (2) the margin relative to anticipated environments (i.e. powder performance as a function of thermal environment variation), and (3) the margin relative to unintended environments (i.e. responses to abnormal environments or safety).

  6. Theory of hydro-equivalent ignition for inertial fusion and its applications to OMEGA and the National Ignition Facility

    SciTech Connect (OSTI)

    Nora, R.; Betti, R.; Bose, A.; Woo, K. M.; Christopherson, A. R.; Meyerhofer, D. D. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); Fusion Science Center, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); Department of Physics and/or Mechanical Engineering, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); Anderson, K. S.; Shvydky, A.; Marozas, J. A.; Collins, T. J. B.; Radha, P. B.; Hu, S. X.; Epstein, R.; Marshall, F. J.; Sangster, T. C. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); McCrory, R. L. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); Department of Physics and/or Mechanical Engineering, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States)

    2014-05-15T23:59:59.000Z

    The theory of ignition for inertial confinement fusion capsules [R. Betti et al., Phys. Plasmas 17, 058102 (2010)] is used to assess the performance requirements for cryogenic implosion experiments on the Omega Laser Facility. The theory of hydrodynamic similarity is developed in both one and two dimensions and tested using multimode hydrodynamic simulations with the hydrocode DRACO [P. B. Radha et al., Phys. Plasmas 12, 032702 (2005)] of hydro-equivalent implosions (implosions with the same implosion velocity, adiabat, and laser intensity). The theory is used to scale the performance of direct-drive OMEGA implosions to the National Ignition Facility (NIF) energy scales and determine the requirements for demonstrating hydro-equivalent ignition on OMEGA. Hydro-equivalent ignition on OMEGA is represented by a cryogenic implosion that would scale to ignition on the NIF at 1.8?MJ of laser energy symmetrically illuminating the target. It is found that a reasonable combination of neutron yield and areal density for OMEGA hydro-equivalent ignition is 3 to 6?×?10{sup 13} and ?0.3?g/cm{sup 2}, respectively, depending on the level of laser imprinting. This performance has not yet been achieved on OMEGA.

  7. Controlling the Electrostatic Discharge Ignition Sensitivity of Composite Energetic Materials Using Carbon Nanotube Additives

    SciTech Connect (OSTI)

    Kade H. Poper; Eric S. Collins; Michelle L. Pantoya; Michael Daniels

    2014-10-01T23:59:59.000Z

    Powder energetic materials are highly sensitive to electrostatic discharge (ESD) ignition. This study shows that small concentrations of carbon nanotubes (CNT) added to the highly reactive mixture of aluminum and copper oxide (Al + CuO) significantly reduces ESD ignition sensitivity. CNT act as a conduit for electric energy, bypassing energy buildup and desensitizing the mixture to ESD ignition. The lowest CNT concentration needed to desensitize ignition is 3.8 vol.% corresponding to percolation corresponding to an electrical conductivity of 0.04 S/cm. Conversely, added CNT increased Al + CuO thermal ignition sensitivity to a hot wire igniter.

  8. Optimally Controlled Flexible Fuel Powertrain System

    SciTech Connect (OSTI)

    Hakan Yilmaz; Mark Christie; Anna Stefanopoulou

    2010-12-31T23:59:59.000Z

    The primary objective of this project was to develop a true Flex Fuel Vehicle capable of running on any blend of ethanol from 0 to 85% with reduced penalty in usable vehicle range. A research and development program, targeting 10% improvement in fuel economy using a direct injection (DI) turbocharged spark ignition engine was conducted. In this project a gasoline-optimized high-technology engine was considered and the hardware and configuration modifications were defined for the engine, fueling system, and air path. Combined with a novel engine control strategy, control software, and calibration this resulted in a highly efficient and clean FFV concept. It was also intended to develop robust detection schemes of the ethanol content in the fuel integrated with adaptive control algorithms for optimized turbocharged direct injection engine combustion. The approach relies heavily on software-based adaptation and optimization striving for minimal modifications to the gasoline-optimized engine hardware system. Our ultimate objective was to develop a compact control methodology that takes advantage of any ethanol-based fuel mixture and not compromise the engine performance under gasoline operation.

  9. Physics Basis and Simulation of Burning Plasma Physics for the Fusion Ignition Research Experiment (FIRE)

    SciTech Connect (OSTI)

    C.E. Kessel; D. Meade; S.C. Jardin

    2002-01-18T23:59:59.000Z

    The FIRE [Fusion Ignition Research Experiment] design for a burning plasma experiment is described in terms of its physics basis and engineering features. Systems analysis indicates that the device has a wide operating space to accomplish its mission, both for the ELMing H-mode reference and the high bootstrap current/high beta advanced tokamak regimes. Simulations with 1.5D transport codes reported here both confirm and constrain the systems projections. Experimental and theoretical results are used to establish the basis for successful burning plasma experiments in FIRE.

  10. Improving the hot-spot pressure and demonstrating ignition hydrodynamic equivalence in cryogenic deuterium–tritium implosions on OMEGA

    SciTech Connect (OSTI)

    Goncharov, V. N.; Sangster, T. C.; Betti, R.; Boehly, T. R.; Bonino, M. J.; Collins, T. J. B.; Craxton, R. S.; Delettrez, J. A.; Edgell, D. H.; Epstein, R.; Follett, R. K.; Forrest, C. J.; Froula, D. H.; Glebov, V. Yu.; Harding, D. R.; Henchen, R. J.; Hu, S. X.; Igumenshchev, I. V.; Janezic, R.; Kelly, J. H. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); and others

    2014-05-15T23:59:59.000Z

    Reaching ignition in direct-drive (DD) inertial confinement fusion implosions requires achieving central pressures in excess of 100 Gbar. The OMEGA laser system [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] is used to study the physics of implosions that are hydrodynamically equivalent to the ignition designs on the National Ignition Facility (NIF) [J. A. Paisner et al., Laser Focus World 30, 75 (1994)]. It is shown that the highest hot-spot pressures (up to 40 Gbar) are achieved in target designs with a fuel adiabat of ? ? 4, an implosion velocity of 3.8?×?10{sup 7}?cm/s, and a laser intensity of ?10{sup 15}?W/cm{sup 2}. These moderate-adiabat implosions are well understood using two-dimensional hydrocode simulations. The performance of lower-adiabat implosions is significantly degraded relative to code predictions, a common feature between DD implosions on OMEGA and indirect-drive cryogenic implosions on the NIF. Simplified theoretical models are developed to gain physical understanding of the implosion dynamics that dictate the target performance. These models indicate that degradations in the shell density and integrity (caused by hydrodynamic instabilities during the target acceleration) coupled with hydrodynamics at stagnation are the main failure mechanisms in low-adiabat designs. To demonstrate ignition hydrodynamic equivalence in cryogenic implosions on OMEGA, the target-design robustness to hydrodynamic instability growth must be improved by reducing laser-coupling losses caused by cross beam energy transfer.

  11. Relationship of Ammonium Nitrogen Distribution to Mineralogy in a Hapludalf Soil1 D. L. SPARKS, R. L. BLEVINS, H. H. BAILEY, AND R. I. BARNHISELZ

    E-Print Network [OSTI]

    Sparks, Donald L.

    Relationship of Ammonium Nitrogen Distribution to Mineralogy in a Hapludalf Soil1 D. L. SPARKS, R to the soil. Additional Index Words: silt mineralogy, clay mineralogy, exchangeable ammonium. Sparks, D. L., R

  12. Investigation of deformation micro-mechanisms in nickel consolidated from a bimodal powder by spark plasma sintering

    E-Print Network [OSTI]

    Gubicza, Jenő

    11 November 2014 Available online 20 November 2014 Keywords: Nickel Spark plasma sintering Bimodal,4]. Recently, much attention has been paid to the novel spark plasma sintering (SPS) consolidation technique [6 plasma sintering D. Tingaud a , P. Jenei b , A. Krawczynska c , F. Mompiou c , J. Gubicza b , G. Dirras a

  13. In vitro study on newly designed biodegradable Fe-X composites (X W, CNT) prepared by spark plasma sintering

    E-Print Network [OSTI]

    Zheng, Yufeng

    iron and the additive secondary phase X using the spark plasma sintering (SPS) method, aiming to obtain on newly designed biodegradable Fe-X composites (X Ľ W, CNT) prepared by spark plasma sintering. J Biomed plasma sintering J. Cheng,1 Y.F. Zheng1,2 1 Center for Biomedical Materials and Tissue Engineering

  14. A simple high-voltage high current spark gap with subnanosecond jitter triggered by femtosecond laser filamentation

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 A simple high-voltage high current spark gap with subnanosecond jitter triggered by femtosecond and able to switch currents in excess of 10 kA with sub-nanosecond jitter. The spark gap is remotely with a nanosecond jitter time2-7 . The jitter could be reduced to hundred of picoseconds with a SF6 filled cell8

  15. The part played by death in the novels of Muriel Spark

    E-Print Network [OSTI]

    Parker, Gillian Russ

    1975-01-01T23:59:59.000Z

    , however, is not so much directed tuward his mother as to her murderer, her old companion named Benny. The end of the novel finds him rushing home to England to do all he can for Benny. Freddy expresses the strongest emotions to death of any Spark... has been seeking, an escape from the absolute boredom of her life and she anticipates rather than fears it. Bizarre events surround deaths which occur in other Spark novels. In The Mandelbaum Gate the murder of an old lady in Iondon is almost...

  16. Volume Ignition via Time-like Detonation in Pellet Fusion

    E-Print Network [OSTI]

    Csernai, L P

    2015-01-01T23:59:59.000Z

    Relativistic fluid dynamics and the theory of relativistic detonation fronts are used to estimate the space-time dynamics of the burning of the D-T fuel in Laser driven pellet fusion experiments. The initial "High foot" heating of the fuel makes the compressed target transparent to radiation, and then a rapid ignition pulse can penetrate and heat up the whole target to supercritical temperatures in a short time, so that most of the interior of the target ignites almost simultaneously and instabilities will have no time to develop. In these relativistic, radiation dominated processes both the interior, time-like burning front and the surrounding space-like part of the front will be stable against Rayleigh-Taylor instabilities. To achieve this rapid, volume ignition the pulse heating up the target to supercritical temperature should provide the required energy in less than ~ 10 ps.

  17. WILDFIRE IGNITION RESISTANCE ESTIMATOR WIZARD SOFTWARE DEVELOPMENT REPORT

    SciTech Connect (OSTI)

    Phillips, M.; Robinson, C.; Gupta, N.; Werth, D.

    2012-10-10T23:59:59.000Z

    This report describes the development of a software tool, entitled “WildFire Ignition Resistance Estimator Wizard” (WildFIRE Wizard, Version 2.10). This software was developed within the Wildfire Ignition Resistant Home Design (WIRHD) program, sponsored by the U. S. Department of Homeland Security, Science and Technology Directorate, Infrastructure Protection & Disaster Management Division. WildFIRE Wizard is a tool that enables homeowners to take preventive actions that will reduce their home’s vulnerability to wildfire ignition sources (i.e., embers, radiant heat, and direct flame impingement) well in advance of a wildfire event. This report describes the development of the software, its operation, its technical basis and calculations, and steps taken to verify its performance.

  18. The ignition of thermonuclear flames in Type Ia supernovae

    E-Print Network [OSTI]

    L. Iapichino; M. Brüggen; W. Hillebrandt; J. C. Niemeyer

    2005-12-12T23:59:59.000Z

    In the framework of the Chandrasekhar-mass deflagration model for Type Ia supernovae (SNe Ia), a persisting free parameter is the initial morphology of the flame front, which is linked to the ignition process in the progenitor white dwarf. Previous analytical models indicate that the thermal runaway is driven by temperature perturbations (''bubbles'') that develop in the white dwarf's convective core. In order to probe the conditions at ignition (diameters, temperatures and evolutionary timescales), we have performed hydrodynamical 2D simulations of buoyant bubbles in white dwarf interiors. Our results show that fragmentation occurring during the bubble rise affects the outcome of the bubble evolution. Possible implications for the ignition process of SNe Ia are discussed.

  19. The ignition of thermonuclear flames in Type Ia supernovae

    E-Print Network [OSTI]

    Iapichino, L; Hillebrandt, W; Niemeyer, J C

    2005-01-01T23:59:59.000Z

    In the framework of the Chandrasekhar-mass deflagration model for Type Ia supernovae (SNe Ia), a persisting free parameter is the initial morphology of the flame front, which is linked to the ignition process in the progenitor white dwarf. Previous analytical models indicate that the thermal runaway is driven by temperature perturbations (''bubbles'') that develop in the white dwarf's convective core. In order to probe the conditions at ignition (diameters, temperatures and evolutionary timescales), we have performed hydrodynamical 2D simulations of buoyant bubbles in white dwarf interiors. Our results show that fragmentation occurring during the bubble rise affects the outcome of the bubble evolution. Possible implications for the ignition process of SNe Ia are discussed.

  20. The effects of cycle-to-cycle variations on nitric oxide (NO) emissions for a spark-ignition engine: Numerical results 

    E-Print Network [OSTI]

    Villarroel, Milivoy

    2004-11-15T23:59:59.000Z

    The objectives of this study were to 1) determine the effects of cycle-to-cycle variations (ccv) on nitric oxide (NO) emissions, and 2) determine if the consideration of ccv affects the average NO emission as compared to ...

  1. Bulk FePt/Fe3Pt nanocomposite magnets prepared by spark plasma Chuan-Bing Rong, Vikas Nandwana, Narayan Poudyal, and J. Ping Liua

    E-Print Network [OSTI]

    Liu, J. Ping

    Bulk FePt/Fe3Pt nanocomposite magnets prepared by spark plasma sintering Chuan-Bing Rong, Vikas nanocomposite magnets from nano- particles remains a great challenge. Spark plasma sintering SPS is known as one; published online 27 April 2007 FePt/Fe3Pt bulk nanocomposite magnets have been prepared by the spark plasma

  2. Interface Driven Energy Filtering of Thermoelectric Power in Spark Plasma Sintered Bi2Te2.7Se0.3 Nanoplatelet Composites

    E-Print Network [OSTI]

    Xiong, Qihua

    Interface Driven Energy Filtering of Thermoelectric Power in Spark Plasma Sintered Bi2Te2.7Se0 of the thermodynamic environment during spark plasma sintering (SPS) on the TE performance of bulk figure of merit, Bi2Te2.7Se0.3 nanoplatelet composites, spark plasma sintering, interfaces, grain

  3. The effect of shock dynamics on compressibility of ignition-scale National Ignition Facility implosions

    SciTech Connect (OSTI)

    Zylstra, A. B.; Frenje, J. A.; Seguin, F. H.; Hicks, D. G.; Dewald, E. L.; Robey, H. F.; Rygg, J. R.; Meezan, N. B.; Rosenberg, M. J.; Rinderknecht, H. G.; Friedrich, S.; Bionta, R.; Olson, R.; Atherton, J.; Barrios, M.; Bell, P.; Benedetti, R.; Berzak Hopkins, L.; Betti, R.; Bradley, D.; Callahan, D.; Casey, D.; Collins, G.; Dixit, S.; Doppner, T.; Edgell, D.; Edwards, M. J.; Gatu Johnson, M.; Glenn, S.; Glenzer, S.; Grim, G.; Hatchett, S.; Jones, O.; Khan, S.; Kilkenny, J.; Kline, J.; Knauer, J.; Kritcher, A.; Kyrala, G.; Landen, O.; LePape, S.; Li, C. K.; Lindl, J.; Ma, T.; Mackinnon, A.; Macphee, A.; Manuel, M. J.-E.; Meyerhofer, D.; Moody, J.; Moses, E.; Nagel, S.R.; Nikroo, A.; Pak, A.; Parham, T.; Petrasso, R. D.; Prasad, R.; Ralph, J.; Rosen, M.; Ross, J. S.; Sangster, T. C.; Sepke, S.; Sinenian, N.; Sio, H. W.; Spears, B.; Springer, P.; Tommasini, R.; Town, R.; Weber, S.; Wilson, D.; Zacharias, R.

    2014-11-01T23:59:59.000Z

    The effects of shock dynamics on compressibility of indirect-drive ignition-scale surrogate implosions, CH shells filled with D3He gas, have been studied using charged-particle spectroscopy. Spectral measurements of D3He protons produced at the shock-bang time probe the shock dynamics and in-flight characteristics of an implosion. The proton shock yield is found to vary by over an order of magnitude. A simple model relates the observed yield to incipient hot-spot adiabat, suggesting that implosions with rapid radiation-power increase during the main drive pulse may have a 2! higher hot-spot adiabat, potentially reducing compressibility. A self-consistent 1-D implosion model was used to infer the areal density (pR) and the shell center-of-mass radius (Rcm) from the downshift of the shock-produced D3He protons. The observed pR at shock-bang time is substantially higher for implosions, where the laser drive is on until near the compression bang time ('short-coast'), while longer-coasting implosions have lower pR. This corresponds to a much larger temporal difference between the shock- and compression-bang time in the long-coast implosions (~800 ps) than in the short-coast (~400 ps); this will be verified with a future direct bang-time diagnostic. This model-inferred differential bang time contradicts radiation-hydrodynamic simulations, which predict constant 700–800 ps differential independent of coasting time; this result is potentially explained by uncertainties in modeling late-time ablation drive on the capsule. In an ignition experiment, an earlier shock-bang time resulting in an earlier onset of shell deceleration, potentially reducing compression and, thus, fuel pR.

  4. The effect of shock dynamics on compressibility of ignition-scale National Ignition Facility implosions

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zylstra, A. B.; Frenje, J. A.; Seguin, F. H.; Hicks, D. G.; Dewald, E. L.; Robey, H. F.; Rygg, J. R.; Meezan, N. B.; Rosenberg, M. J.; Rinderknecht, H. G.; Friedrich, S.; Bionta, R.; Olson, R.; Atherton, J.; Barrios, M.; Bell, P.; Benedetti, R.; Berzak Hopkins, L.; Betti, R.; Bradley, D.; Callahan, D.; Casey, D.; Collins, G.; Dixit, S.; Doppner, T.; Edgell, D.; Edwards, M. J.; Gatu Johnson, M.; Glenn, S.; Glenzer, S.; Grim, G.; Hatchett, S.; Jones, O.; Khan, S.; Kilkenny, J.; Kline, J.; Knauer, J.; Kritcher, A.; Kyrala, G.; Landen, O.; LePape, S.; Li, C. K.; Lindl, J.; Ma, T.; Mackinnon, A.; Macphee, A.; Manuel, M. J.-E.; Meyerhofer, D.; Moody, J.; Moses, E.; Nagel, S.R.; Nikroo, A.; Pak, A.; Parham, T.; Petrasso, R. D.; Prasad, R.; Ralph, J.; Rosen, M.; Ross, J. S.; Sangster, T. C.; Sepke, S.; Sinenian, N.; Sio, H. W.; Spears, B.; Springer, P.; Tommasini, R.; Town, R.; Weber, S.; Wilson, D.; Zacharias, R.

    2014-11-01T23:59:59.000Z

    The effects of shock dynamics on compressibility of indirect-drive ignition-scale surrogate implosions, CH shells filled with D3He gas, have been studied using charged-particle spectroscopy. Spectral measurements of D3He protons produced at the shock-bang time probe the shock dynamics and in-flight characteristics of an implosion. The proton shock yield is found to vary by over an order of magnitude. A simple model relates the observed yield to incipient hot-spot adiabat, suggesting that implosions with rapid radiation-power increase during the main drive pulse may have a 2! higher hot-spot adiabat, potentially reducing compressibility. A self-consistent 1-D implosion model was used to infer the areal density (pR) and the shell center-of-mass radius (Rcm) from the downshift of the shock-produced D3He protons. The observed pR at shock-bang time is substantially higher for implosions, where the laser drive is on until near the compression bang time ('short-coast'), while longer-coasting implosions have lower pR. This corresponds to a much larger temporal difference between the shock- and compression-bang time in the long-coast implosions (~800 ps) than in the short-coast (~400 ps); this will be verified with a future direct bang-time diagnostic. This model-inferred differential bang time contradicts radiation-hydrodynamic simulations, which predict constant 700–800 ps differential independent of coasting time; this result is potentially explained by uncertainties in modeling late-time ablation drive on the capsule. In an ignition experiment, an earlier shock-bang time resulting in an earlier onset of shell deceleration, potentially reducing compression and, thus, fuel pR.

  5. The effect of shock dynamics on compressibility of ignition-scale National Ignition Facility implosions

    SciTech Connect (OSTI)

    Zylstra, A. B., E-mail: zylstra@mit.edu; Frenje, J. A.; Séguin, F. H.; Rosenberg, M. J.; Rinderknecht, H. G.; Gatu Johnson, M.; Li, C. K.; Manuel, M. J.-E.; Petrasso, R. D.; Sinenian, N.; Sio, H. W. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Hicks, D. G.; Dewald, E. L.; Robey, H. F.; Rygg, J. R.; Meezan, N. B.; Friedrich, S.; Bionta, R.; Atherton, J.; Barrios, M. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); and others

    2014-11-15T23:59:59.000Z

    The effects of shock dynamics on compressibility of indirect-drive ignition-scale surrogate implosions, CH shells filled with D{sup 3}He gas, have been studied using charged-particle spectroscopy. Spectral measurements of D{sup 3}He protons produced at the shock-bang time probe the shock dynamics and in-flight characteristics of an implosion. The proton shock yield is found to vary by over an order of magnitude. A simple model relates the observed yield to incipient hot-spot adiabat, suggesting that implosions with rapid radiation-power increase during the main drive pulse may have a 2× higher hot-spot adiabat, potentially reducing compressibility. A self-consistent 1-D implosion model was used to infer the areal density (?R) and the shell center-of-mass radius (R{sub cm}) from the downshift of the shock-produced D{sup 3}He protons. The observed ?R at shock-bang time is substantially higher for implosions, where the laser drive is on until near the compression bang time (“short-coast”), while longer-coasting implosions have lower ?R. This corresponds to a much larger temporal difference between the shock- and compression-bang time in the long-coast implosions (?800 ps) than in the short-coast (?400 ps); this will be verified with a future direct bang-time diagnostic. This model-inferred differential bang time contradicts radiation-hydrodynamic simulations, which predict constant 700–800 ps differential independent of coasting time; this result is potentially explained by uncertainties in modeling late-time ablation drive on the capsule. In an ignition experiment, an earlier shock-bang time resulting in an earlier onset of shell deceleration, potentially reducing compression and, thus, fuel ?R.

  6. The effect of shock dynamics on compressibility of ignition-scale National Ignition Facility implosions

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zylstra, A. B.; Frenje, J. A.; Seguin, F. H.; Hicks, D. G.; Dewald, E. L.; Robey, H. F.; Rygg, J. R.; Meezan, N. B.; Rosenberg, M. J.; Rinderknecht, H. G.; et al

    2014-11-01T23:59:59.000Z

    The effects of shock dynamics on compressibility of indirect-drive ignition-scale surrogate implosions, CH shells filled with D3He gas, have been studied using charged-particle spectroscopy. Spectral measurements of D3He protons produced at the shock-bang time probe the shock dynamics and in-flight characteristics of an implosion. The proton shock yield is found to vary by over an order of magnitude. A simple model relates the observed yield to incipient hot-spot adiabat, suggesting that implosions with rapid radiation-power increase during the main drive pulse may have a 2! higher hot-spot adiabat, potentially reducing compressibility. A self-consistent 1-D implosion model was used to infermore »the areal density (pR) and the shell center-of-mass radius (Rcm) from the downshift of the shock-produced D3He protons. The observed pR at shock-bang time is substantially higher for implosions, where the laser drive is on until near the compression bang time ('short-coast'), while longer-coasting implosions have lower pR. This corresponds to a much larger temporal difference between the shock- and compression-bang time in the long-coast implosions (~800 ps) than in the short-coast (~400 ps); this will be verified with a future direct bang-time diagnostic. This model-inferred differential bang time contradicts radiation-hydrodynamic simulations, which predict constant 700–800 ps differential independent of coasting time; this result is potentially explained by uncertainties in modeling late-time ablation drive on the capsule. In an ignition experiment, an earlier shock-bang time resulting in an earlier onset of shell deceleration, potentially reducing compression and, thus, fuel pR.« less

  7. Exhaust gas recirculation in a homogeneous charge compression ignition engine

    DOE Patents [OSTI]

    Duffy, Kevin P. (Metamora, IL); Kieser, Andrew J. (Morton, IL); Rodman, Anthony (Chillicothe, IL); Liechty, Michael P. (Chillicothe, IL); Hergart, Carl-Anders (Peoria, IL); Hardy, William L. (Peoria, IL)

    2008-05-27T23:59:59.000Z

    A homogeneous charge compression ignition engine operates by injecting liquid fuel directly in a combustion chamber, and mixing the fuel with recirculated exhaust and fresh air through an auto ignition condition of the fuel. The engine includes at least one turbocharger for extracting energy from the engine exhaust and using that energy to boost intake pressure of recirculated exhaust gas and fresh air. Elevated proportions of exhaust gas recirculated to the engine are attained by throttling the fresh air inlet supply. These elevated exhaust gas recirculation rates allow the HCCI engine to be operated at higher speeds and loads rendering the HCCI engine a more viable alternative to a conventional diesel engine.

  8. Features of a point design for fast ignition

    SciTech Connect (OSTI)

    Tabak, M; Clark, D; Town, R J; Key, M H; Amendt, P; Ho, D; Meeker, D J; Shay, H D; Lasinski, B F; Kemp, A; Divol, L; Mackinnon, A J; Patel, P; Strozzi, D; Grote, D P

    2009-10-26T23:59:59.000Z

    Fast Ignition is an inertial fusion scheme in which fuel is first assembled and then heated to the ignition temperature with an external heating source. In this note we consider cone and shell implosions where the energy supplied by short pulse lasers is transported to the fuel by electrons. We describe possible failure modes for this scheme and how to overcome them. In particular, we describe two sources of cone tip failure, an axis jet driven from the compressed fuel mass and hard photon preheat leaking through the implosion shell, and laser prepulse that can change the position of laser absorption and the angular distribution of the emitted electrons.

  9. Analysis of combustion in a small homogeneous charge compression assisted ignition engine

    E-Print Network [OSTI]

    237 Analysis of combustion in a small homogeneous charge compression assisted ignition engine H Ma1 characteristics to homogeneous charge compression ignition (HCCI) engines. Difficulties such as unknown ignition timing and the polytropic index have been addressed by combining both heat release and mass fraction burn

  10. Flamelet-based modeling of auto-ignition with thermal inhomogeneities for application

    E-Print Network [OSTI]

    Pitsch, Heinz

    Flamelet-based modeling of auto-ignition with thermal inhomogeneities for application to HCCI National Laboratories, Livermore, CA 94551, USA Abstract Homogeneous-charge compression ignition (HCCI ignition engines. However, HCCI engines expe- rience very large heat release rates which can cause too

  11. Increased Hot-Plate Ignition Probability for Nanoparticle-Laden Diesel Fuel

    E-Print Network [OSTI]

    Pacheco, Jose Rafael

    Increased Hot-Plate Ignition Probability for Nanoparticle-Laden Diesel Fuel Himanshu Tyagi, Patrick April 2, 2008 ABSTRACT The present study attempts to improve the ignition properties of diesel fuel, droplet ignition experiments were carried out atop a heated hot plate. Different types of fuel mixtures

  12. ICDERS July 2429, 2011 Irvine, USA An Empirical Model for the Ignition of Aluminum Particle

    E-Print Network [OSTI]

    23rd ICDERS July 24­29, 2011 Irvine, USA An Empirical Model for the Ignition of Aluminum Particle of aluminum particle clouds is developed and applied to the study of particle ignition and combustion behavior as cloud concentration effects on ignition. The total mass of aluminum that burns is found to depend

  13. Vehicle Technologies Office Merit Review 2014: The Application of High Energy Ignition and Boosting/Mixing Technology to Increase Fuel Economy in Spark Ignition Gasoline Engines by Increasing EGR Dilution Capability

    Broader source: Energy.gov [DOE]

    Presentation given by General Motors LLC at 2014 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about the application of high...

  14. Silvia Solano's interest in carbon sequestration was first sparked on a six-month internship

    E-Print Network [OSTI]

    Yang, Zong-Liang

    Silvia Solano's interest in carbon sequestration was first sparked on a six-month internship experiments combining EOR with carbon sequestration. "I thought this was a win-win solution," she said. "You of a research team conduct- ing a large-scale test of carbon sequestration. "I knew I wanted to learn more about

  15. Mechanisms of Nickel on A. M. SCHEIDEGGER*, D. L. SPARKS, Univ. of Delaware, M. FENDORF,

    E-Print Network [OSTI]

    Sparks, Donald L.

    Mechanisms of Nickel on A. M. SCHEIDEGGER*, D. L. SPARKS, Univ. of Delaware, M. FENDORF, Univ. of Berkeley, and G. M. LAMBLE, Brookhaven National Laboratory. Nickel adsorption on the edge swfaces be divided into two pH regions. In the lower pH region (pH nickel adsorption increased

  16. Page 1 of 7 Modeling and simulation of sparking in fastening assemblies

    E-Print Network [OSTI]

    of these mechanisms depends on the material used for the assembly (for example, metal rib with carbon composite of the bolt and a possible sparking occurrence. INTRODUCTION The massive use of composite materials in modern the electric conductivity of metallic fasteners and the conductivity of composite materials increases

  17. Mechanical Study of Copper Bonded at Low Temperature using Spark Plasma Sintering Process

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    is approximatively 6.47 MPa [7]. J. W. Elmer & al [8] have presented a diffusion bonding of high purity copper using a conventional furnace. A series of diffusion bonds was done to determine the relationship between bond strengthMechanical Study of Copper Bonded at Low Temperature using Spark Plasma Sintering Process Bassem

  18. Elaboration of architectured materials by spark plasma sintering FABREGUE Damien1,a

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    has been used to realize diffusion bonding. In that case again, bonding can be realized at low the same mechanical strength as pure copper even for diffusion time of a few minutes. Secondly, bonding has veronique.massardier@insa-lyon.fr Keywords: architectured materials, spark plasma sintering, bonding, porous

  19. Inertial Confinement Fusion Ignition and High Yield Campaign

    E-Print Network [OSTI]

    : Provide mission need report for the proposed OMEGA Extended Performance project. · October 2002: NNSA November 21, 2003 #12;2 Statements to FESAC IFE panel 10/28/03 · Ignition is a major goal for NNSA supports OFES's mission and OFES use of NNSA's ICF facilities is accepted · Defense Programs reserves right

  20. Carbon dioxide emission during forest fires ignited by lightning

    E-Print Network [OSTI]

    Magdalena Pelc; Radoslaw Osuch

    2009-03-31T23:59:59.000Z

    In this paper we developed the model for the carbon dioxide emission from forest fire. The master equation for the spreading of the carbon dioxide to atmosphere is the hyperbolic diffusion equation. In the paper we study forest fire ignited by lightning. In that case the fores fire has the well defined front which propagates with finite velocity.

  1. Thermite powder ignition by localized microwaves Yehuda Meir, Eli Jerby

    E-Print Network [OSTI]

    Jerby, Eli

    - propagating high-temperature synthesis (SHS) for sintering of ceramic composites [14]. The magnetic (H, the microwave energy is supplied locally to the powder. It creates a confined hotspot, and initiates a self-propagating the powder prior to its ignition is simulated theoretically, taking into account the powder's temperature

  2. Software solutions manage the definition, operation, maintenance and configuration control of the National Ignition Facility

    SciTech Connect (OSTI)

    Dobson, D; Churby, A; Krieger, E; Maloy, D; White, K

    2011-07-25T23:59:59.000Z

    The National Ignition Facility (NIF) is the world's largest laser composed of millions of individual parts brought together to form one massive assembly. Maintaining control of the physical definition, status and configuration of this structure is a monumental undertaking yet critical to the validity of the shot experiment data and the safe operation of the facility. The NIF business application suite of software provides the means to effectively manage the definition, build, operation, maintenance and configuration control of all components of the National Ignition Facility. State of the art Computer Aided Design software applications are used to generate a virtual model and assemblies. Engineering bills of material are controlled through the Enterprise Configuration Management System. This data structure is passed to the Enterprise Resource Planning system to create a manufacturing bill of material. Specific parts are serialized then tracked along their entire lifecycle providing visibility to the location and status of optical, target and diagnostic components that are key to assessing pre-shot machine readiness. Nearly forty thousand items requiring preventive, reactive and calibration maintenance are tracked through the System Maintenance & Reliability Tracking application to ensure proper operation. Radiological tracking applications ensure proper stewardship of radiological and hazardous materials and help provide a safe working environment for NIF personnel.

  3. Simulation of hydrogen and hydrogen-assisted propane ignition in Pt catalyzed microchannel

    SciTech Connect (OSTI)

    Seshadri, Vikram; Kaisare, Niket S. [Department of Chemical Engineering, Indian Institute of Technology - Madras, Chennai 600 036 (India)

    2010-11-15T23:59:59.000Z

    This paper deals with self-ignition of catalytic microburners from ambient cold-start conditions. First, reaction kinetics for hydrogen combustion is validated with experimental results from the literature, followed by validation of a simplified pseudo-2D microburner model. The model is then used to study the self-ignition behavior of lean hydrogen/air mixtures in a Platinum-catalyzed microburner. Hydrogen combustion on Pt is a very fast reaction. During cold start ignition, hydrogen conversion reaches 100% within the first few seconds and the reactor dynamics are governed by the ''thermal inertia'' of the microburner wall structure. The self-ignition property of hydrogen can be used to provide the energy required for propane ignition. Two different modes of hydrogen-assisted propane ignition are considered: co-feed mode, where the microburner inlet consists of premixed hydrogen/propane/air mixtures; and sequential feed mode, where the inlet feed is switched from hydrogen/air to propane/air mixtures after the microburner reaches propane ignition temperature. We show that hydrogen-assisted ignition is equivalent to selectively preheating the inlet section of the microburner. The time to reach steady state is lower at higher equivalence ratio, lower wall thermal conductivity, and higher inlet velocity for both the ignition modes. The ignition times and propane emissions are compared. Although the sequential feed mode requires slightly higher amount of hydrogen, the propane emissions are at least an order of magnitude lower than the other ignition modes. (author)

  4. High Efficiency, Low Emissions Homogeneous Charge Compression Ignition (HCCI) Engines

    SciTech Connect (OSTI)

    None

    2011-01-31T23:59:59.000Z

    This is the final report of the High Efficiency Clean Combustion (HECC) Research Program for the U.S. Department of Energy. Work under this co-funded program began in August 2005 and finished in July 2010. The objective of this program was to develop and demonstrate a low emission, high thermal efficiency engine system that met 2010 EPA heavy-duty on-highway truck emissions requirements (0.2g/bhp-hr NOx, 0.14g/bhp-hr HC and 0.01g/bhp-hr PM) with a thermal efficiency of 46%. To achieve this goal, development of diesel homogenous charge compression ignition (HCCI) combustion was the chosen approach. This report summarizes the development of diesel HCCI combustion and associated enabling technologies that occurred during the HECC program between August 2005 and July 2010. This program showed that although diesel HCCI with conventional US diesel fuel was not a feasible means to achieve the program objectives, the HCCI load range could be increased with a higher volatility, lower cetane number fuel, such as gasoline, if the combustion rate could be moderated to avoid excessive cylinder pressure rise rates. Given the potential efficiency and emissions benefits, continued research of combustion with low cetane number fuels and the effects of fuel distillation are recommended. The operation of diesel HCCI was only feasible at part-load due to a limited fuel injection window. A 4% fuel consumption benefit versus conventional, low-temperature combustion was realized over the achievable operating range. Several enabling technologies were developed under this program that also benefited non-HCCI combustion. The development of a 300MPa fuel injector enabled the development of extended lifted flame combustion. A design methodology for minimizing the heat transfer to jacket water, known as precision cooling, will benefit conventional combustion engines, as well as HCCI engines. An advanced combustion control system based on cylinder pressure measurements was developed. A Well-to-wheels analysis of the energy flows in a mobile vehicle system and a 2nd Law thermodynamic analysis of the engine system were also completed under this program.

  5. azelastine nasal spray: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    for spark-ignition en- gines Lee, Tonghun 394 ILASS Europe 2013, 25th European Conference on Liquid Atomization and Spray Systems, Chania, Greece, 1-4 September 2013...

  6. 2007-01-0175 Development of an Experimental Database and Chemical

    E-Print Network [OSTI]

    Pitsch, Heinz

    homogeneous charge compression ignition (HCCI) operation, are carefully identified. Both short and long term such as homogeneous charge compression ignition (HCCI) engines and spark ignition (SI) engines. Unfortunately

  7. "Studying the physics and mechanics that underlie the flight

    E-Print Network [OSTI]

    Acton, Scott

    -Direct Injection Engine Technologies Direct injection engines are internal combustion engines with spark ignition

  8. ISSN 0280-5316 ISRN LUTFD2/TFRT--5864--SE

    E-Print Network [OSTI]

    motorkalibrering) Abstract Engine knock is an undesired phenomenon in spark ignited internal combustion engines

  9. An experimental and modeling study of iso-octane ignition delay times under homogeneous charge compression ignition conditions

    SciTech Connect (OSTI)

    He, X.; Donovan, M.T.; Zigler, B.T.; Palmer, T.R.; Walton, S.M.; Wooldridge, M.S.; Atreya, A. [Department of Mechanical Engineering, University of Michigan, 2350 Hayward Street, Ann Arbor, MI 48109-2125 (United States)

    2005-08-01T23:59:59.000Z

    Autoignition of iso-octane was examined using a rapid compression facility (RCF) with iso-octane, oxygen, nitrogen, and argon mixtures. The effects of typical homogeneous charge compression ignition (HCCI) conditions on the iso-octane ignition characteristics were studied. Experimental results for ignition delay times, t{sub ign}, were obtained from pressure time-histories. The experiments were conducted over a range of equivalence ratios (f=0.25-1.0), pressures (P=5.12-23 atm), temperatures (T=943-1027 K), and oxygen mole fractions ({chi}{sub O{sub 2}}=9-21%), and with the addition of trace amounts of combustion product gases (CO{sub 2} and H{sub 2}O). It was found that the ignition delay times were well represented by the expression t{sub ign}=1.3x10{sup -4}P{sup -1.05}f{sup -0.77}{chi}{sub O{sub 2}}{sup -1.41}exp(33,700/R{sub (c} {sub al/mol/K)}T), where P is pressure (atm), T is temperature (K), f is the equivalence ratio (based on iso-octane to O{sub 2} molar ratios), {chi}{sub O{sub 2}} is the oxygen mole percent (%), and t{sub ign} is the ignition delay time (ms). Carbon dioxide was found to have no chemical effect on t{sub ign}. Water was found to systematically decrease t{sub ign} by a small amount (less than 14% for the range of conditions studied). The maximum uncertainty in the measured t{sub ign} is +/-12% with an average uncertainty of +/-6%. The performance of several proposed chemical reaction mechanisms (including detailed, reduced, and skeletal mechanisms) was evaluated in the context of the current experimental results.

  10. Partial fuel stratification to control HCCI heat release rates : fuel composition and other factors affecting pre-ignition reactions of two-stage ignition fuels.

    SciTech Connect (OSTI)

    Dec, John E.; Sjoberg, Carl-Magnus G.; Cannella, William (Chevron USA Inc.); Yang, Yi; Dronniou, Nicolas

    2010-11-01T23:59:59.000Z

    Homogeneous charge compression ignition (HCCI) combustion with fully premixed charge is severely limited at high-load operation due to the rapid pressure-rise rates (PRR) which can lead to engine knock and potential engine damage. Recent studies have shown that two-stage ignition fuels possess a significant potential to reduce the combustion heat release rate, thus enabling higher load without knock.

  11. In vitro degradation and biocompatibility of FePd and FePt composites fabricated by spark plasma sintering

    E-Print Network [OSTI]

    Zheng, Yufeng

    rate than pure iron, Fe-5 wt.%Pd and Fe-5 wt.%Pt composites were prepared by spark plasma sinteringIn vitro degradation and biocompatibility of Fe­Pd and Fe­Pt composites fabricated by spark plasma sintering T. Huang a,b , J. Cheng c , Y.F. Zheng a,b,c, a State Key Laboratory for Turbulence and Complex

  12. The Absence of Plasma in "Spark Plasma Sintering"

    E-Print Network [OSTI]

    Hulbert, Dustin M.

    2008-01-01T23:59:59.000Z

    distributions. Materials Science and Engineering A, 2005.reactivity. Materials Science and Engineering A, 2005. 394(system (SPS). Materials Science and Engineering A, 2000.

  13. MnBi particles with high energy density made by spark erosion

    SciTech Connect (OSTI)

    Nguyen, Phi-Khanh, E-mail: phi@ucsd.edu; Jin, Sungho [Materials Science and Engineering, University of California, San Diego, La Jolla, California 92093 (United States); Center for Magnetic Recording Research, University of California, San Diego, La Jolla, California 92093 (United States); Berkowitz, Ami E. [Physics Department, University of California, San Diego, La Jolla, California 92093 (United States); Center for Magnetic Recording Research, University of California, San Diego, La Jolla, California 92093 (United States)

    2014-05-07T23:59:59.000Z

    We report on the properties of low-temperature phase (LTP)-MnBi particles produced by the rapid-quenching technique of spark-erosion. The as-prepared powder consists of amorphous, crystalline, and superparamagnetic particles, mostly as porous aggregates. The major fraction of the powder consists of 20–30?nm particles. A short anneal crystallizes the amorphous particles producing a high moment, >90% of theoretical M{sub S}, albeit with H{sub C} of a few kOe. If lightly milled, the agglomerates are broken up to yield H{sub C} of 1?T. These findings are supported by the x-ray diffraction pattern showing broadened peaks of the predominant LTP-MnBi phase. The combination of spark erosion, milling, and annealing has produced randomly oriented particles with (BH){sub MAX}???3.0 MGOe. The particles are expected to show record energy product when aligned along their crystallographic easy axes.

  14. Inertial Confinement Fusion and the National Ignition Facility (NIF)

    SciTech Connect (OSTI)

    Ross, P.

    2012-08-29T23:59:59.000Z

    Inertial confinement fusion (ICF) seeks to provide sustainable fusion energy by compressing frozen deuterium and tritium fuel to extremely high densities. The advantages of fusion vs. fission are discussed, including total energy per reaction and energy per nucleon. The Lawson Criterion, defining the requirements for ignition, is derived and explained. Different confinement methods and their implications are discussed. The feasibility of creating a power plant using ICF is analyzed using realistic and feasible numbers. The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory is shown as a significant step forward toward making a fusion power plant based on ICF. NIF is the world’s largest laser, delivering 1.8 MJ of energy, with a peak power greater than 500 TW. NIF is actively striving toward the goal of fusion energy. Other uses for NIF are discussed.

  15. Hydrodynamic instabilities in beryllium targets for the National Ignition Facility

    SciTech Connect (OSTI)

    Yi, S. A., E-mail: austinyi@lanl.gov; Simakov, A. N.; Wilson, D. C.; Olson, R. E.; Kline, J. L.; Batha, S. H. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, New Mexico 87545 (United States); Clark, D. S.; Hammel, B. A.; Milovich, J. L.; Salmonson, J. D.; Kozioziemski, B. J. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551 (United States)

    2014-09-15T23:59:59.000Z

    Beryllium ablators offer higher ablation velocity, rate, and pressure than their carbon-based counterparts, with the potential to increase the probability of achieving ignition at the National Ignition Facility (NIF) [E. I. Moses et al., Phys. Plasmas 16, 041006 (2009)]. We present here a detailed hydrodynamic stability analysis of low (NIF Revision 6.1) and high adiabat NIF beryllium target designs. Our targets are optimized to fully utilize the advantages of beryllium in order to suppress the growth of hydrodynamic instabilities. This results in an implosion that resists breakup of the capsule, and simultaneously minimizes the amount of ablator material mixed into the fuel. We quantify the improvement in stability of beryllium targets relative to plastic ones, and show that a low adiabat beryllium capsule can be at least as stable at the ablation front as a high adiabat plastic target.

  16. Development of an Experimental Facility for Flame Speed Measurements in Powdered Aerosols

    E-Print Network [OSTI]

    Vissotski, Andrew John

    2012-10-19T23:59:59.000Z

    with both dispersion techniques, a pure dust-air system would not ignite due to the current spark ignition system. Thus, a hybrid mixture of Al/CH4/O2/N2 was employed to achieve the project goal of demonstrating a system for controlled laminar flame speed...

  17. High load operation in a homogeneous charge compression ignition engine

    DOE Patents [OSTI]

    Duffy, Kevin P. (Metamora, IL); Kieser, Andrew J. (Morton, IL); Liechty, Michael P. (Chillicothe, IL); Hardy, William L. (Peoria, IL); Rodman, Anthony (Chillicothe, IL); Hergart, Carl-Anders (Peoria, IL)

    2008-12-23T23:59:59.000Z

    A homogeneous charge compression ignition engine is set up by first identifying combinations of compression ratio and exhaust gas percentages for each speed and load across the engines operating range. These identified ratios and exhaust gas percentages can then be converted into geometric compression ratio controller settings and exhaust gas recirculation rate controller settings that are mapped against speed and load, and made available to the electronic

  18. CARBON DEFLAGRATION IN TYPE Ia SUPERNOVA. I. CENTRALLY IGNITED MODELS

    SciTech Connect (OSTI)

    Ma, H.; Woosley, S. E.; Malone, C. M. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Almgren, A.; Bell, J. [Center for Computational Sciences and Engineering, Lawrence Berkeley National Lab, Berkeley, CA 94720 (United States)

    2013-07-01T23:59:59.000Z

    A leading model for Type Ia supernovae (SNe Ia) begins with a white dwarf near the Chandrasekhar mass that ignites a degenerate thermonuclear runaway close to its center and explodes. In a series of papers, we shall explore the consequences of ignition at several locations within such dwarfs. Here we assume central ignition, which has been explored before, but is worth revisiting, if only to validate those previous studies and to further elucidate the relevant physics for future work. A perturbed sphere of hot iron ash with a radius of {approx}100 km is initialized at the middle of the star. The subsequent explosion is followed in several simulations using a thickened flame model in which the flame speed is either fixed-within the range expected from turbulent combustion-or based on the local turbulent intensity. Global results, including the explosion energy and bulk nucleosynthesis (e.g., {sup 56}Ni of 0.48-0.56 M{sub Sun }) turn out to be insensitive to this speed. In all completed runs, the energy released by the nuclear burning is adequate to unbind the star, but not enough to give the energy and brightness of typical SNe Ia. As found previously, the chemical stratification observed in typical events is not reproduced. These models produce a large amount of unburned carbon and oxygen in central low velocity regions, which is inconsistent with spectroscopic observations, and the intermediate mass elements and iron group elements are strongly mixed during the explosion.

  19. Nonpremixed ignition, laminar flame propagation, and mechanism reduction of n-butanol, iso-butanol, and methyl butanoate

    SciTech Connect (OSTI)

    Lu, Wei; Kelley, A. P.; Law, C. K.

    2011-01-01T23:59:59.000Z

    The non-premixed ignition temperature of n-butanol (CH{sub 3}CH{sub 2}CH{sub 2}CH{sub 2}OH), iso-butanol ((CH{sub 3}){sub 2}CHCH{sub 2}OH) and methyl butanoate (CH{sub 3}CH{sub 2}CH{sub 2}COOCH{sub 3}) was measured in a liquid pool assembly by heated oxidizer in a stagnation flow for system pressures of 1 and 3 atm. In addition, the stretch-corrected laminar flame speeds of mixtures of air–n-butanol/iso-butanol/methyl butanoate were determined from the outwardly propagating spherical flame at initial pressures of up to 2 atm, for an extensive range of equivalence ratio. The ignition temperature and laminar flame speeds of n-butanol and methyl butanoate were computationally simulated with three recently developed kinetic mechanisms in the literature. Dominant reaction pathways to ignition and flame propagation were identified and discussed through a chemical explosive mode analysis (CEMA) and sensitivity analysis. The detailed models were further reduced through a series of systematic strategies. The reduced mechanisms provided excellent agreement in both homogeneous and diffusive combustion environments and greatly improved the computation efficiency.

  20. Ignition and extinction in the catalytic oxidation of hydrocarbons over platinum

    SciTech Connect (OSTI)

    Veser, G.; Schmidt, L.D. [Univ. of Minnesota, Minneapolis, MN (United States). Dept. of Chemical Engineering and Materials Science] [Univ. of Minnesota, Minneapolis, MN (United States). Dept. of Chemical Engineering and Materials Science

    1996-04-01T23:59:59.000Z

    The ignition-extinction behavior in the oxidation of methane, ethane, propane and isobutane, as well as of ethylene and propylene over a platinum-foil catalyst was studied over the entire range of fuel/air ratios at atmospheric pressure. Ignition and extinction of the heterogeneous surface reaction, homogeneous ignition and the autothermal behavior of these fuel-air mixtures were investigated. The results show a common trend in the ignition extinction behavior of the alkanes and a different trend for the olefins. This is discussed in terms of a simple model, which correctly predicts the composition dependence of the surface ignition curve for reasonable values of parameters, indicating a mainly oxygen-covered surface during ignition of the alkanes and a mainly hydrocarbon-covered surface in the case of the olefins. Different branches of the complete bifurcation diagrams are discussed separately, allowing qualitative conclusions about the catalytic activity of Pt for the oxidation reactions of different fuels.

  1. Electrically heated particulate filter enhanced ignition strategy

    SciTech Connect (OSTI)

    Gonze, Eugene V; Paratore, Jr., Michael J

    2012-10-23T23:59:59.000Z

    An exhaust system that processes exhaust generated by an engine is provided. The system generally includes a particulate filter (PF) that filters particulates from the exhaust wherein an upstream end of the PF receives exhaust from the engine. A grid of electrically resistive material is applied to an exterior upstream surface of the PF and selectively heats exhaust passing through the grid to initiate combustion of particulates within the PF. A catalyst coating applied to at least one of the PF and the grid. A control module estimates a temperature of the grid and controls the engine to produce a desired exhaust product to increase the temperature of the grid.

  2. Ignition probabilities of wildland fuels based on simulated lightning discharges. Forest Service research paper

    SciTech Connect (OSTI)

    Latham, D.J.; Schlieter, J.A.

    1989-09-01T23:59:59.000Z

    Ignition of wildland fine fuels by lightning was simulated with an electric arc discharge in the laboratory. The results showed that fuel parameters such as depth, moisture content, bulk density, and mineral content can be combined with the duration of the simulated continuing current to give ignition probabilities. The fuel state parameters of importance and the ignition probabilities were determined using logistic regression. Graphs, tables, formulas, and a FORTRAN computer program are given for field use.

  3. Investigation of proton focusing and conversion efficiency for proton fast ignition

    E-Print Network [OSTI]

    Bartal, Teresa Jean

    2012-01-01T23:59:59.000Z

    After ignition, a thermonuclear burn wave spreads radiallythe shell to create the thermonuclear burn wave. At 10 keV,heating the plasma to thermonuclear temperatures. Protons

  4. Group ignition and combustion of a cloud of char particles under transient conditions

    E-Print Network [OSTI]

    Ramalingam, Suresh Chander

    1988-01-01T23:59:59.000Z

    Correction Factor M/Mrpc. 6. 8 Results with CO Oxidation in the Gas Phase. 6. 8. 1 Ignition 6. 8. 2 Effect of Particle Size on Ignition Times 6. 8. 3 Effect of Ambient Temperature on Ignition 6. 8. 4 CO Ignition 6. 8. 5 Combustion with the Thin Flame... has its own euvelope flame (Figure 2. 1a). If another burning drop is brought near the droplet, then a common flame is formed for the two droplets (Figure 2. 1b). Thus the simplest example of group combustion is the combustion of two single drops...

  5. A Home Ignition Assessment Model Applied to Structures in the Wildland-Urban Interface

    SciTech Connect (OSTI)

    Biswas, Kaushik [ORNL; Werth, David [Savannah River National Laboratory, Aiken, SC; Gupta, Narendra [Savannah River National Laboratory, Aiken, SC

    2013-01-01T23:59:59.000Z

    The issue of exterior fire threat to buildings, from either wildfires in the wildland-urban interface or neighboring structure fires, is critically important. To address this, theWildfire Ignition Resistant Home Design (WIRHD) program was initiated. The WIRHD program developed a tool, theWildFIREWizard, that will allow homeowners to estimate the external fire threat to their homes based on specific features and characteristics of the homes and yards. The software then makes recommendations to reduce the threat. The inputs include the structural and material features of the home and information about any ignition sources or flammable objects in its immediate vicinity, known as the home ignition zone. The tool comprises an ignition assessment model that performs explicit calculations of the radiant and convective heating of the building envelope from the potential ignition sources. This article describes a series of material ignition and flammability tests that were performed to calibrate and/or validate the ignition assessment model. The tests involved exposing test walls with different external siding types to radiant heating and/or direct flame contact.The responses of the test walls were used to determine the conditions leading to melting, ignition, or any other mode of failure of the walls. Temperature data were used to verify the model predictions of temperature rises and ignition times of the test walls.

  6. High Efficiency GDI Engine Research, with Emphasis on Ignition Systems

    Broader source: Energy.gov [DOE]

    2013 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting

  7. Laser Ignition and Diagnostic Systems Delivered by Flexible Optical Fibers

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12electron 9 5 - -/e),,sandLaser Decontamination ofFaraday-

  8. A laser triggered vacuum spark x-ray lithography source 

    E-Print Network [OSTI]

    Keating, Richard Allen

    1987-01-01T23:59:59.000Z

    was 50 cm. Obviously, this type of configurat, ion is totally impractical for a step and repeat system. Synchrotron radiation is being considered as an x-ray lithography source. Many laboratories are experi- menting with synchrotron sources. Also... for production of submicron geometries and improvements needed is presented. 1v ACKNOWLEDGMENT This thesis was made possible through the assistance of a number of people. Huang Wei Ling helped gather much of the data presented in this thesis. She also...

  9. Fabrication of Tungsten-Rhenium Cladding materials via Spark Plasma Sintering for Ultra High Temperature Reactor Applications

    SciTech Connect (OSTI)

    Charit, Indrajit; Butt, Darryl; Frary, Megan; Carroll, Mark

    2012-11-05T23:59:59.000Z

    This research will develop an optimized, cost-effective method for producing high-purity tungsten-rhenium alloyed fuel clad forms that are crucial for the development of a very high-temperature nuclear reactor. The study will provide critical insight into the fundamental behavior (processing-microstructure- property correlations) of W-Re alloys made using this new fabrication process comprising high-energy ball milling (HEBM) and spark plasma sintering (SPS). A broader goal is to re-establish the U.S. lead in the research field of refractory alloys, such as W-Re systems, with potential applications in very high-temperature nuclear reactors. An essential long-term goal for nuclear power is to develop the capability of operating nuclear reactors at temperatures in excess of 1,000K. This capability has applications in space exploration and some special terrestrial uses where high temperatures are needed in certain chemical or reforming processes. Refractory alloys have been identified as being capable of withstanding temperatures in excess of 1,000K and are considered critical for the development of ultra hightemperature reactors. Tungsten alloys are known to possess extraordinary properties, such as excellent high-temperature capability, including the ability to resist leakage of fissile materials when used as a fuel clad. However, there are difficulties with the development of refractory alloys: 1) lack of basic experimental data on thermodynamics and mechanical and physical properties, and 2) challenges associated with processing these alloys.

  10. ENERGY PARTITIONING, ENERGY COUPLING (EPEC) EXPERIMENTS AT THE NATIONAL IGNITION FACILITY

    SciTech Connect (OSTI)

    Fournier, K B; Brown, C G; May, M J; Dunlop, W H; Compton, S M; Kane, J O; Mirkarimi, P B; Guyton, R L; Huffman, E

    2012-01-05T23:59:59.000Z

    The energy-partitioning, energy-coupling (EPEC) experiments at the National Ignition Facility (NIF) will simultaneously measure the coupling of energy into both ground shock and air-blast overpressure from a laser-driven target. The source target for the experiment is positioned at a known height above the ground-surface simulant and is heated by four beams from NIF. The resulting target energy density and specific energy are equal to those of a low-yield nuclear device. The ground-shock stress waves and atmospheric overpressure waveforms that result in our test system are hydrodynamically scaled analogs of seismic and air-blast phenomena caused by a nuclear weapon. In what follows, we discuss the motivation for our investigation and briefly describe NIF. Then, we introduce the EPEC experiments, including diagnostics, in more detail.

  11. Overview of the preliminary safety analysis of the National Ignition Facility

    SciTech Connect (OSTI)

    Brereton, S.; McLouth, L.; Odell, B. [Lawrence Livermore National Lab., CA (United States)] [and others] [Lawrence Livermore National Lab., CA (United States); and others

    1997-06-01T23:59:59.000Z

    The National Ignition Facility (NIF) is a proposed U.S. Department of Energy inertial confinement laser fusion facility. The candidate sites for locating the NIF are: Los Alamos National Laboratory, Sandia National Laboratory, New Mexico, the Nevada Test Site, and Lawrence Livermore National Laboratory (LLNL), the preferred site. The NIF will operate by focusing 192 individual laser beams onto a tiny deuterium-tritium target located at the center of a spherical target chamber. The NIF has been classified as a low hazard, radiological facility on the basis of a preliminary hazards analysis and according to the DOE methodology for facility classification. This requires that a safety analysis report be prepared under DOE Order 5481.1B, Safety Analysis and Review System. A Preliminary Safety Analysis Report (PSAR) has been approved, which documents and evaluates the safety issues associated with the construction, operation, and decommissioning of the NIF. 10 refs., 6 figs., 4 tabs.

  12. Overview of the gamma reaction history diagnostic for the national ignition facility (NIF)

    SciTech Connect (OSTI)

    Kim, Yong Ho [Los Alamos National Laboratory; Evans, Scott C [Los Alamos National Laboratory; Herrmann, Hans W [Los Alamos National Laboratory; Mack, Joseph M [Los Alamos National Laboratory; Young, Carl S [Los Alamos National Laboratory; Malone, Robert M [Los Alamos National Laboratory; Cox, Brian C [Los Alamos National Laboratory; Frogget, Brent C [Los Alamos National Laboratory; Kaufman, Morris I [Los Alamos National Laboratory; Tunnell, Thomas W [Los Alamos National Laboratory; Tibbitts, Aric [Los Alamos National Laboratory; Palagi, Martin J [NST/LAS VEGAS; Stoeffl, Wolfgang [LLNL

    2010-01-01T23:59:59.000Z

    The National Ignition Facility (NIF) has a need for measuring gamma radiation as part of a nuclear diagnostic program. A new gamma-detection diagnostic uses 900 off-axis parabolic mirrors to rel ay Cherenkov light from a volume of pressurized gas. This non imaging optical system has the high-speed detector placed at a stop position with the Cherenkov light delayed until after the prompt gammas have passed through the detector. Because of the wavelength range (250 to 700 nm), the optical element surface finish was a key design constraint. A cluster of four channels (each set to a different gas pressure) will collect the time histories for different energy ranges of gammas.

  13. Gasoline Engine Economy as Affected by the Time of Ignition

    E-Print Network [OSTI]

    Hopkins, George Jay

    1907-01-01T23:59:59.000Z

    of Ignition. A Thesis Sutaitted to the faculty of the University of Kansas hy George Jay Hopkins, Eor the Degree of B.S. in MeohanioaX Engineering. Lawrenoe 1907 The author desires to make grateful acknowledg­ ment of the friendly aid and advice...­ ment in this line Is not only possible, but in most cas­ es profitable* Considering the almost infinite variety of uses to which the internal combustion engine is put, it is manifestly impossible to set any one angle of advance, at which the maximum...

  14. Create Facebook applications with CodeIgniter Integrating the Facebook SDK

    E-Print Network [OSTI]

    Create Facebook applications with CodeIgniter Integrating the Facebook SDK Skill Level to incorporate the Facebook SDK into the CodeIgniter framework, using the available functions to create applications. This article shows you how to get the sample Facebook application working with the Code

  15. A comparison of various models in predicting ignition delay in single-particle coal combustion

    E-Print Network [OSTI]

    A comparison of various models in predicting ignition delay in single-particle coal combustion November 2013 Accepted 7 January 2014 Available online xxxx Keywords: Coal Devolatilization Ignition delay a b s t r a c t In this paper, individual coal particle combustion under laminar conditions

  16. Ignition and Combustion of Fuel Pockets Moving in an Oxidizing Atmosphere

    E-Print Network [OSTI]

    Heil, Matthias

    Ignition and Combustion of Fuel Pockets Moving in an Oxidizing Atmosphere JOEL DAOU Dpto, Spain. E-mail: daou@tupi.dmt.upm.es Ignition and combustion of an initially spherical pocket of fuel, the results provide a good appreciation of the dynamics of the combustion process. For example, it is found

  17. Wildfire ignition resistant home design(WIRHD) program: Full-scale testing and demonstration final report.

    SciTech Connect (OSTI)

    Quarles, Stephen, L.; Sindelar, Melissa

    2011-12-13T23:59:59.000Z

    The primary goal of the Wildfire ignition resistant home design(WIRHD) program was to develop a home evaluation tool that could assess the ignition potential of a structure subjected to wildfire exposures. This report describes the tests that were conducted, summarizes the results, and discusses the implications of these results with regard to the vulnerabilities to homes and buildings.

  18. Jet Ignition Research for Clean Efficient Combustion Engines Prasanna Chinnathambi, Abdullah Karimi, Manikanda Rajagopal, Razi Nalim

    E-Print Network [OSTI]

    Zhou, Yaoqi

    Jet Ignition Research for Clean Efficient Combustion Engines Prasanna Chinnathambi, Abdullah Karimi University Indianapolis Abstract Ignition by a jet of hot gas has application in lean-burn pre-chamber internal combustion engines and in innovative pressure-gain combustors for gas turbine engines. Jet

  19. Dynamics of Homogeneous Charge Compression Ignition (HCCI) Engines with High Dilution

    E-Print Network [OSTI]

    Stefanopoulou, Anna

    Dynamics of Homogeneous Charge Compression Ignition (HCCI) Engines with High Dilution C. J. Chiang (HCCI) engines in light of the cycle-to-cycle thermal feedback due to the high percentage of exhaust temperature is the primary mechanism for con- trolling ignition timing in an HCCI engine, especially when

  20. EFFECTS OF MIXTURE INHOMOGENEITY ON THE AUTO-IGNITION OF REACTANTS UNDER HCCI ENVIRONMENT

    E-Print Network [OSTI]

    Im, Hong G.

    EFFECTS OF MIXTURE INHOMOGENEITY ON THE AUTO-IGNITION OF REACTANTS UNDER HCCI ENVIRONMENT Ramanan ABSTRACT As an attempt at providing insight to develop bet- ter modeling strategies for HCCI engines in multi-dimensional simulation of HCCI engines. INTRODUCTION The homogenous charge compression ignition

  1. Plasma channel from EP beam Direct-drive ignition is the main thrust in LLE

    E-Print Network [OSTI]

    -drive ignition; this is not an optimal configuration fordirectdrivethatrequiressphericalillumination I2093 for direct-drive experiments; it is coupled to a high-power, short-pulse laser (OMEGA EP) to explore advanced 26 kJ Scale 1:70 in energy Scale 1:1 Scale 1:1 #12;Hydro-equivalentignitiononOMEGA #12;Ignition

  2. KINETIC MODELING OF A SURROGATE DIESEL FUEL APPLIED TO 3D AUTO-IGNITION IN HCCI ENGINES

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    KINETIC MODELING OF A SURROGATE DIESEL FUEL APPLIED TO 3D AUTO-IGNITION IN HCCI ENGINES R OF A SURROGATE DIESEL FUEL APPLIED TO 3D AUTO-IGNITION IN HCCI ENGINES INTRODUCTION Engines running on HCCI combustion mode (Homogeneous Charge Compression Ignition) have the potential to provide both diesel

  3. Reconstruction of 2D x-ray radiographs at the National Ignition Facility using pinhole tomography (invited)

    SciTech Connect (OSTI)

    Field, J. E., E-mail: field9@llnl.gov; Rygg, J. R.; Barrios, M. A.; Benedetti, L. R.; Döppner, T.; Izumi, N.; Jones, O.; Khan, S. F.; Ma, T.; Nagel, S. R.; Pak, A.; Tommasini, R.; Bradley, D. K.; Town, R. P. J. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    2014-11-15T23:59:59.000Z

    Two-dimensional radiographs of imploding fusion capsules are obtained at the National Ignition Facility by projection through a pinhole array onto a time-gated framing camera. Parallax among images in the image array makes it possible to distinguish contributions from the capsule and from the backlighter, permitting correction of backlighter non-uniformities within the capsule radiograph. Furthermore, precise determination of the imaging system geometry and implosion velocity enables combination of multiple images to reduce signal-to-noise and discover new capsule features.

  4. Ignition and extinction phenomena in helium micro hollow cathode discharges

    SciTech Connect (OSTI)

    Kulsreshath, M. K.; Schwaederle, L.; Dufour, T.; Lefaucheux, P.; Dussart, R. [GREMI, CNRS/Université d'Orléans (UMR7344), Orléans (France); Sadeghi, N. [LIPhy, CNRS and Universite Joseph Fourier (UMR5588), Grenoble (France); Overzet, L. J. [GREMI, CNRS/Université d'Orléans (UMR7344), Orléans (France); PSAL, UTDallas, Richardson, Texas 75080-3021 (United States)

    2013-12-28T23:59:59.000Z

    Micro hollow cathode discharges (MHCD) were produced using 250??m thick dielectric layer of alumina sandwiched between two nickel electrodes of 8??m thickness. A through cavity at the center of the chip was formed by laser drilling technique. MHCD with a diameter of few hundreds of micrometers allowed us to generate direct current discharges in helium at up to atmospheric pressure. A slowly varying ramped voltage generator was used to study the ignition and the extinction periods of the microdischarges. The analysis was performed by using electrical characterisation of the V-I behaviour and the measurement of He*({sup 3}S{sub 1}) metastable atoms density by tunable diode laser spectroscopy. At the ignition of the microdischarges, 2??s long current peak as high as 24?mA was observed, sometimes followed by low amplitude damped oscillations. At helium pressure above 400?Torr, an oscillatory behaviour of the discharge current was observed just before the extinction of the microdischarges. The same type of instability in the extinction period at high pressure also appeared on the density of He*({sup 3}S{sub 1}) metastable atoms, but delayed by a few ?s relative to the current oscillations. Metastable atoms thus cannot be at the origin of the generation of the observed instabilities.

  5. Direct Injection Compression Ignition Diesel Automotive Technology Education GATE Program

    SciTech Connect (OSTI)

    Anderson, Carl L

    2006-09-25T23:59:59.000Z

    The underlying goal of this prqject was to provide multi-disciplinary engineering training for graduate students in the area of internal combustion engines, specifically in direct injection compression ignition engines. The program was designed to educate highly qualified engineers and scientists that will seek to overcome teclmological barriers preventing the development and production of cost-effective high-efficiency vehicles for the U.S. market. Fu1iher, these highly qualified engineers and scientists will foster an educational process to train a future workforce of automotive engineering professionals who are knowledgeable about and have experience in developing and commercializing critical advanced automotive teclmologies. Eight objectives were defmed to accomplish this goal: 1. Develop an interdisciplinary internal co1nbustion engine curriculum emphasizing direct injected combustion ignited diesel engines. 2. Encourage and promote interdisciplinary interaction of the faculty. 3. Offer a Ph.D. degree in internal combustion engines based upon an interdisciplinary cuniculum. 4. Promote strong interaction with indusuy, develop a sense of responsibility with industry and pursue a self sustaining program. 5. Establish collaborative arrangements and network universities active in internal combustion engine study. 6. Further Enhance a First Class educational facility. 7. Establish 'off-campus' M.S. and Ph.D. engine programs of study at various indusuial sites. 8. Extend and Enhance the Graduate Experience.

  6. Advanced Concept Exploration for Fast Ignition Science Program, Final Report

    SciTech Connect (OSTI)

    Stephens, Richard Burnite [General Atomics; McLean, Harry M. [Lawrence Livermore National Laboratory; Theobald, Wolfgang [Laboratory for Laser Energetics; Akli, Kramer U. [The Ohio State University; Beg, Farhat N. [University of California, San Diego; Sentoku, Yasuhiko [University of Nevada, Reno; Schumacher, Douglass W. [The Ohio State University; Wei, Mingsheng [General Atomics

    2013-09-04T23:59:59.000Z

    The Fast Ignition (FI) Concept for Inertial Confinement Fusion (ICF) has the potential to provide a significant advance in the technical attractiveness of Inertial Fusion Energy reactors. FI differs from conventional “central hot spot” (CHS) target ignition by decoupling compression from heating: using a laser (or heavy ion beam or Z pinch) drive pulse (10’s of nanoseconds) to create a dense fuel and a second, much shorter (~10 picoseconds) high intensity pulse to ignite a small volume within the dense fuel. The physics of fast ignition process was the focus of our Advanced Concept Exploration (ACE) program. Ignition depends critically on two major issues involving Relativistic High Energy Density (RHED) physics: The laser-induced creation of fast electrons and their propagation in high-density plasmas. Our program has developed new experimental platforms, diagnostic packages, computer modeling analyses, and taken advantage of the increasing energy available at laser facilities to advance understanding of the fundamental physics underlying these issues. Our program had three thrust areas: • Understand the production and characteristics of fast electrons resulting from FI relevant laser-plasma interactions and their dependence on laser prepulse and laser pulse length. • Investigate the subsequent fast electron transport in solid and through hot (FI-relevant) plasmas. • Conduct and understand integrated core-heating experiments by comparison to simulations. Over the whole period of this project (three years for this contract), we have greatly advanced our fundamental understanding of the underlying properties in all three areas: • Comprehensive studies on fast electron source characteristics have shown that they are controlled by the laser intensity distribution and the topology and plasma density gradient. Laser pre-pulse induced pre-plasma in front of a solid surface results in increased stand-off distances from the electron origin to the high density target as well as large and erratic spread of the electron beam with increasing short pulse duration. We have demonstrated, using newly available higher contrast lasers, an improved energy coupling, painting a promising picture for FI feasibility. • Our detailed experiments and analyses of fast electron transport dependence on target material have shown that it is feasible to collimate fast electron beam by self-generated resistive magnetic fields in engineered targets with a rather simple geometry. Stable and collimated electron beam with spot size as small as 50-?m after >100-?m propagation distance (an angular divergence angle of 20°!) in solid density plasma targets has been demonstrated with FI-relevant (10-ps, >1-kJ) laser pulses Such collimated beam would meet the required heating beam size for FI. • Our new experimental platforms developed for the OMEGA laser (i.e., i) high resolution 8 keV backlighter platform for cone-in-shell implosion and ii) the 8 keV imaging with Cu-doped shell targets for detailed transport characterization) have enabled us to experimentally confirm fuel assembly from cone-in-shell implosion with record-high areal density. We have also made the first direct measurement of fast electron transport and spatial energy deposition in integrated FI experiments enabling the first experiment-based benchmarking of integrated simulation codes. Executing this program required a large team. It was managed as a collaboration between General Atomics (GA), Lawrence Livermore National Laboratory (LLNL), and the Laboratory for Laser Energetics (LLE). GA fulfills its responsibilities jointly with the University of California, San Diego (UCSD), The Ohio State University (OSU) and the University of Nevada at Reno (UNR). The division of responsibility was as follows: (1) LLE had primary leadership for channeling studies and the integrated energy transfer, (2) LLNL led the development of measurement methods, analysis, and deployment of diagnostics, and (3) GA together with UCSD, OSU and UNR studied the detailed energy-transfer physics. Th

  7. fine-grained microcrystalline Si3N4 product produced after an additional short period of spark-discharge milling. Silicon can be

    E-Print Network [OSTI]

    Stepanov, Misha

    -density nanocrystalline titanium nitride compacts by plasma-activated sintering of mechanically reacted powder. Met. Materfine-grained microcrystalline Si3N4 product produced after an additional short period of spark and because there is no requirement to remove hydrogen. Spark-discharge milling was successfully employed

  8. On the critical flame radius and minimum ignition energy for spherical flame initiation

    SciTech Connect (OSTI)

    Chen, Zheng; Burke, M. P.; Ju, Yiguang

    2011-01-01T23:59:59.000Z

    Spherical flame initiation from an ignition kernel is studied theoretically and numerically using different fuel/oxygen/helium/argon mixtures (fuel: hydrogen, methane, and propane). The emphasis is placed on investigating the critical flame radius controlling spherical flame initiation and its correlation with the minimum ignition energy. It is found that the critical flame radius is different from the flame thickness and the flame ball radius and that their relationship depends strongly on the Lewis number. Three different flame regimes in terms of the Lewis number are observed and a new criterion for the critical flame radius is introduced. For mixtures with Lewis number larger than a critical Lewis number above unity, the critical flame radius is smaller than the flame ball radius but larger than the flame thickness. As a result, the minimum ignition energy can be substantially over-predicted (under-predicted) based on the flame ball radius (the flame thickness). The results also show that the minimum ignition energy for successful spherical flame initiation is proportional to the cube of the critical flame radius. Furthermore, preferential diffusion of heat and mass (i.e. the Lewis number effect) is found to play an important role in both spherical flame initiation and flame kernel evolution after ignition. It is shown that the critical flame radius and the minimum ignition energy increase significantly with the Lewis number. Therefore, for transportation fuels with large Lewis numbers, blending of small molecule fuels or thermal and catalytic cracking will significantly reduce the minimum ignition energy.

  9. Preheat of radiative shock in double-shell ignition targets

    SciTech Connect (OSTI)

    Li, J. W.; He, X. T. [Key Lab of High Energy Density Physics Simulation, Center for Applied Physics and Technology, Peking University, Beijing 100871 (China) [Key Lab of High Energy Density Physics Simulation, Center for Applied Physics and Technology, Peking University, Beijing 100871 (China); Institute of Applied Physics and Computational Mathematics, P.O. Box 8009, Beijing 100094 (China); Pei, W. B.; Li, J. H.; Zheng, W. D.; Zhu, S. P. [Institute of Applied Physics and Computational Mathematics, P.O. Box 8009, Beijing 100094 (China)] [Institute of Applied Physics and Computational Mathematics, P.O. Box 8009, Beijing 100094 (China); Kang, W. [Key Lab of High Energy Density Physics Simulation, Center for Applied Physics and Technology, Peking University, Beijing 100871 (China)] [Key Lab of High Energy Density Physics Simulation, Center for Applied Physics and Technology, Peking University, Beijing 100871 (China)

    2013-08-15T23:59:59.000Z

    For the double-shell ignition target, the nonuniform preheat of the inner shell by high-energy x rays, especially the M-band line radiation and L-shell radiation from the Au hohlraum, aggravates the hydrodynamic instability that causes shell disruption. In this paper, for the first time, we propose another preheating mechanism due to the radiative shock formed in the CH foam, and also confirm and validate such preheat of radiative shock by numerical results. We also give an estimate of the improved double-shell in which the CH foam is replaced by the metallic foam to mitigate the hydrodynamic instabilities, and find that the radiative shock formed in the metallic foam produces a much stronger radiation field to preheat the inner shell, which plays a role in better controlling the instabilities. In double-shells, the preheat of radiative shock, as a potential effect on the instabilities, should be seriously realized and underlined.

  10. Pathway to a lower cost high repetition rate ignition facility

    SciTech Connect (OSTI)

    Obenschain, S.P.; Colombant, D.G.; Schmitt, A.J.; Sethian, J.D.; McGeoch, M. W. [Plasma Physics Division, U.S. Naval Research Laboratory, Washington, D.C. 20375 (United States); Plex LLC, Brookline, Massachusetts 02446-5478 (United States)

    2006-05-15T23:59:59.000Z

    An approach to a high-repetition ignition facility based on direct drive with the krypton-fluoride laser is presented. The objective is development of a 'Fusion Test Facility' that has sufficient fusion power to be useful as a development test bed for power plant materials and components. Calculations with modern pellet designs indicate that laser energies well below a megajoule may be sufficient. A smaller driver would result in an overall smaller, less complex and lower cost facility. While this facility might appear to have most direct utility to inertial fusion energy, the high flux of neutrons would also be able to address important issues concerning materials and components for other approaches to fusion energy. The physics and technological basis for the Fusion Test Facility are presented along with a discussion of its applications.

  11. Shock-ignition relevant experiments with planar targets on OMEGA

    SciTech Connect (OSTI)

    Hohenberger, M.; Hu, S. X.; Anderson, K. S.; Boehly, T. R.; Sangster, T. C.; Seka, W.; Stoeckl, C.; Yaakobi, B. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States)] [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States); Theobald, W.; Lafon, M.; Nora, R. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States) [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States); Fusion Science Center, University of Rochester, Rochester, New York 14623 (United States); Betti, R.; Meyerhofer, D. D. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States) [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States); Fusion Science Center, University of Rochester, Rochester, New York 14623 (United States); Departments of Mechanical Engineering and Physics, University of Rochester, Rochester, New York 14627 (United States); Casner, A. [CEA, DAM, DIF, Arpajon (France)] [CEA, DAM, DIF, Arpajon (France); Fratanduono, D. E. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550 (United States)] [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550 (United States); Ribeyre, X.; Schurtz, G. [Centre Lasers Intenses et Applications, CELIA, Université Bordeaux 1-CEA-CNRS, Talence (France)] [Centre Lasers Intenses et Applications, CELIA, Université Bordeaux 1-CEA-CNRS, Talence (France)

    2014-02-15T23:59:59.000Z

    We report on laser-driven, strong-shock generation and hot-electron production in planar targets in the presence of a pre-plasma at shock-ignition (SI) relevant laser and pre-plasma conditions. 2-D simulations reproduce the shock dynamics well, indicating ablator shocks of up to 75 Mbar have been generated. We observe hot-electron temperatures of ?70?keV at intensities of 1.4?×?10{sup 15}?W/cm{sup 2} with multiple overlapping beams driving the two-plasmon decay instability. When extrapolated to SI-relevant intensities of ?10{sup 16}?W/cm{sup 2}, the hot electron temperature will likely exceed 100?keV, suggesting that tightly focused beams without overlap are better suited for launching the ignitor shock.

  12. Physics Regimes in the Fusion Ignition Research Experiment (FIRE)

    SciTech Connect (OSTI)

    D.M. Meade; S.C.Jardin; C.E. Kessel; M.A. Ulrickson; J.H. Schultz; P.H. Rutherford; J.A. Schmidt; J.C. Wesley; K.M. Young; N.A.Uckan; R.J. Thome; P. Heitzenroeder; B.E. Nelson; and C.C.Baker

    2001-06-19T23:59:59.000Z

    Burning plasma science is recognized widely as the next frontier in fusion research. The Fusion Ignition Research Experiment (FIRE) is a design study of a next-step burning plasma experiment with the goal of developing a concept for an experimental facility to explore and understand the strong nonlinear coupling among confinement, magnetohydrodynamic (MHD) self-heating, stability, edge physics, and wave-particle interactions that is fundamental to fusion plasma behavior. This will require plasmas dominated by alpha heating (Q greater than or equal to 5) that are sustained for a duration comparable to characteristic plasma timescales (greater than or equal to 10) tau(subscript ''E''), approximately 4 tau(subscript ''He''), approximately 2 tau(subscript ''skin''). The work reported here has been undertaken with the objective of finding the minimum size (cost) device to achieve these physics goals.

  13. Report on ignitability testing of flammable gasses in a core sampling drill string

    SciTech Connect (OSTI)

    Witwer, K.S., Westinghouse Hanford

    1996-12-01T23:59:59.000Z

    This document describes the results from testing performed at the Pittsburgh Research Center to determine the effects of an ignition of flammable gasses contained in a core sampling drill string. Testing showed that 1) An ignition of stoichiometric hydrogen and air in a vented 30 or 55 ft length of drill string will not force 28`` or more of water out the bottom of the drill string, and 2) An ignition of this same gas mixture will not rupture a vented or completely sealed drill string.

  14. Elliptical magnetic mirror generated via resistivity gradients for fast ignition inertial confinement fusion

    SciTech Connect (OSTI)

    Robinson, A. P. L.; Schmitz, H. [Central Laser Facility, STFC Rutherford-Appleton Laboratory, Didcot OX11 0QX (United Kingdom)] [Central Laser Facility, STFC Rutherford-Appleton Laboratory, Didcot OX11 0QX (United Kingdom)

    2013-06-15T23:59:59.000Z

    The elliptical magnetic mirror scheme for guiding fast electrons for Fast Ignition proposed by Schmitz et al. (Plasma Phys. Controlled Fusion 54, 085016 (2012)) is studied for conditions on the multi-kJ scale which are much closer to full-scale Fast Ignition. When scaled up, the elliptical mirror scheme is still highly beneficial to Fast Ignition. An increase in the coupling efficiency by a factor of 3–4 is found over a wide range of fast electron divergence half-angles.

  15. Fuel Effects on Ignition and Their Impact on Advanced Combustion Engines (Poster)

    SciTech Connect (OSTI)

    Taylor, J.; Li, H.; Neill, S.

    2006-08-01T23:59:59.000Z

    The objective of this report is to develop a pathway to use easily measured ignition properties as metrics for characterizing fuels in advanced combustion engine research--correlate IQT{trademark} measured parameters with engine data. In HCCL engines, ignition timing depends on the reaction rates throughout compression stroke: need to understand sensitivity to T, P, and [O{sub 2}]; need to rank fuels based on more than one set of conditions; and need to understand how fuel composition (molecular species) affect ignition properties.

  16. A low cost igniter utilizing an SCB and titanium sub-hydride potassium perchlorate pyrotechnic

    SciTech Connect (OSTI)

    Bickes, R.W. Jr.; Grubelich, M.C. [Sandia National Labs., Albuquerque, NM (United States); Hartman, J.K.; McCampbell, C.B. [SCB Technologies, Inc., Albuquerque, NM (United States); Churchill, J.K. [Quantic-Holex, Hollister, CA (United States)

    1993-12-31T23:59:59.000Z

    A conventional NSI (NASA standard initiator) normally employs a hot-wire ignition element to ignite ZPP (zirconium potassium perchlorate). With minor modifications to the interior of a header similar to an NSI device to accommodate an SCB (semiconductor bridge), a low cost initiator was obtained. In addition, the ZPP was replaced with THKP (titanium subhydride potassium perchlorate) to obtain increased overall gas production and reduced static-charge sensitivity. This paper reports on the all-fire and no-fire levels obtained and on a dual mix device that uses THKP as the igniter mix and a thermite as the output mix.

  17. Polar-direct-drive experiments on the National Ignition Facility

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Hohenberger, M.; Radha, P. B.; Myatt, J. F.; LePape, S.; Marozas, J. A.; Marshall, F. J.; Michel, D. T.; Regan, S. P.; Seka, W.; Shvydky, A.; et al

    2015-05-01T23:59:59.000Z

    To support direct-drive inertial confinement fusion experiments at the National Ignition Facility (NIF) [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 43, 2841 (2004)] in its indirect-drive beam configuration, the polar-direct-drive (PDD) concept [S. Skupsky et al., Phys. Plasmas 11, 2763 (2004)] has been proposed. Ignition in PDD geometry requires direct-drive–specific beam smoothing, phase plates, and repointing the NIF beams toward the equator to ensure symmetric target irradiation. First experiments to study the energetics and preheat in PDD implosions at the NIF have been performed. These experiments utilize the NIF in its current configuration, including beammore »geometry, phase plates, and beam smoothing. Room-temperature, 2.2-mm-diam plastic shells filled with D? gas were imploded with total drive energies ranging from ~500 to 750 kJ with peak powers of 120 to 180 TW and peak on-target irradiances at the initial target radius from 8 10ą? to 1.2 10ą?W/cm˛. Results from these initial experiments are presented, including measurements of shell trajectory, implosion symmetry, and the level of hot-electron preheat in plastic and Si ablators. Experiments are simulated with the 2-D hydrodynamics code DRACO including a full 3-D ray-trace to model oblique beams, and models for nonlocal electron transport and cross-beam energy transport (CBET). These simulations indicate that CBET affects the shell symmetry and leads to a loss of energy imparted onto the shell, consistent with the experimental data.« less

  18. Polar-direct-drive experiments on the National Ignition Facility

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Hohenberger, M. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States)] (ORCID:0000000258879711); Radha, P. B. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); Myatt, J. F. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); LePape, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Marozas, J. A. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); Marshall, F. J. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); Michel, D. T. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States)] (ORCID:0000000166894359); Regan, S. P. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); Seka, W. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); Shvydky, A. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); Sangster, T. C. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States)] (ORCID:0000000340402672); Bates, J. W. [U. S. Naval Research Lab., Washington, DC (United States)] (ORCID:0000000188087240); Betti, R. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); Boehly, T. R. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); Bonino, M. J. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); Casey, D. T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Collins, T. J. B. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); Craxton, R. S. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States)] (ORCID:0000000158858227); Delettrez, J. A. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); Edgell, D. H. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); Epstein, R. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States)] (ORCID:0000000340628444); Fiksel, G. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); Fitzsimmons, P. [General Atomics, San Diego, CA (United States); Frenje, J. A. [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States)] (ORCID:0000000168460378); Froula, D. H. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); Goncharov, V. N. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); Harding, D. R. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); Kalantar, D. H. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Karasik, M. [U. S. Naval Research Lab., Washington, DC (United States); Kessler, T. J. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); Kilkenny, J. D. [General Atomics, San Diego, CA (United States); Knauer, J. P. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); Kurz, C. [General Atomics, San Diego, CA (United States); Lafon, M. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); LaFortune, K. N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); MacGowan, B. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Mackinnon, A. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); MacPhee, A. G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)] (ORCID:0000000341604479); McCrory, R. L. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); McKenty, P. W. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); Meeker, J. F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Meyerhofer, D. D. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States)

    2015-05-01T23:59:59.000Z

    To support direct-drive inertial confinement fusion experiments at the National Ignition Facility (NIF) [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 43, 2841 (2004)] in its indirect-drive beam configuration, the polar-direct-drive (PDD) concept [S. Skupsky et al., Phys. Plasmas 11, 2763 (2004)] has been proposed. Ignition in PDD geometry requires direct-drive–specific beam smoothing, phase plates, and repointing the NIF beams toward the equator to ensure symmetric target irradiation. First experiments to study the energetics and preheat in PDD implosions at the NIF have been performed. These experiments utilize the NIF in its current configuration, including beam geometry, phase plates, and beam smoothing. Room-temperature, 2.2-mm-diam plastic shells filled with D? gas were imploded with total drive energies ranging from ~500 to 750 kJ with peak powers of 120 to 180 TW and peak on-target irradiances at the initial target radius from 8 10ą? to 1.2 10ą?W/cm˛. Results from these initial experiments are presented, including measurements of shell trajectory, implosion symmetry, and the level of hot-electron preheat in plastic and Si ablators. Experiments are simulated with the 2-D hydrodynamics code DRACO including a full 3-D ray-trace to model oblique beams, and models for nonlocal electron transport and cross-beam energy transport (CBET). These simulations indicate that CBET affects the shell symmetry and leads to a loss of energy imparted onto the shell, consistent with the experimental data.

  19. The Making of Beauty: Aesthetic Spaces in the Fiction of D. H. Lawrence, Muriel Spark, and Virginia Woolf 

    E-Print Network [OSTI]

    Lee, Joori

    2013-08-01T23:59:59.000Z

    This dissertation rethinks textual images of the other’s beauty, depicted in works by D. H. Lawrence, Muriel Spark, and Virginia Woolf, whose fascination with the other, called by this dissertation the beloved, urged them to inscribe the beloved’s...

  20. Observations and Modeling of Long Negative Laboratory Discharges: Identifying the Physics Important to an Electrical Spark in Air

    SciTech Connect (OSTI)

    Biagi, C J; Uman, M A

    2011-12-13T23:59:59.000Z

    There are relatively few reports in the literature focusing on negative laboratory leaders. Most of the reports focus exclusively on the simpler positive laboratory leader that is more commonly encountered in high voltage engineering [Gorin et al., 1976; Les Renardieres Group, 1977; Gallimberti, 1979; Domens et al., 1994; Bazelyan and Raizer 1998]. The physics of the long, negative leader and its positive counterpart are similar; the two differ primarily in their extension mechanisms [Bazelyan and Raizer, 1998]. Long negative sparks extend primarily by an intermittent process termed a 'step' that requires the development of secondary leader channels separated in space from the primary leader channel. Long positive sparks typically extend continuously, although, under proper conditions, their extension can be temporarily halted and begun again, and this is sometimes viewed as a stepping process. However, it is emphasized that the nature of positive leader stepping is not like that of negative leader stepping. There are several key observational studies of the propagation of long, negative-polarity laboratory sparks in air that have aided in the understanding of the stepping mechanisms exhibited by such sparks [e.g., Gorin et al., 1976; Les Renardieres Group, 1981; Ortega et al., 1994; Reess et al., 1995; Bazelyan and Raizer, 1998; Gallimberti et al., 2002]. These reports are reviewed below in Section 2, with emphasis placed on the stepping mechanism (the space stem, pilot, and space leader). Then, in Section 3, reports pertaining to modeling of long negative leaders are summarized.

  1. Thermodynamics of Potassium Exchange in Soil Using a Kinetics Approach1 D. L. SPARKS AND P. M. JARDINEZ

    E-Print Network [OSTI]

    Sparks, Donald L.

    Thermodynamics of Potassium Exchange in Soil Using a Kinetics Approach1 D. L. SPARKS AND P. M. JARDINEZ ABSTRACT Thermodynamics of potassium (K) exchange using a kinetics ap- proach was investigated that more energy was needed to desorb K than to adsorb K. Thermodynamic and pseudother- modynamic parameters

  2. Temperature dependence of magnetic behaviour in very fine grained, spark plasma sintered NiCuZn Ferrites

    E-Print Network [OSTI]

    Boyer, Edmond

    CuZn Ferrites Behzad Ahmadi,1, a) Karim Zehani,1 Martino LoBue,1 Vincent Loyau,1 and Frederic Mazaleyrat1 SATIE spark plasma sintering technique, a family of very fine grained, fully dense NiCuZn ferrites have been produced which show constant permeability up to several 10 MHz. These Ferrites can be used for filtering

  3. Sorption and Desorption of Acetonitrile on Montmorillonite from Aqueous Solutions Z. Z. Zhang,* D. L. Sparks, and R. A. Pease

    E-Print Network [OSTI]

    Sparks, Donald L.

    Sorption and Desorption of Acetonitrile on Montmorillonite from Aqueous Solutions Z. Z. Zhang,* D. L. Sparks, and R. A. Pease ABSTRACT The sorption and desorption of acetonitrile on K, Na, Ca, and Mg- trometer and the c-axis spacings of K, Ca, and Mg montmorillonite in the acetonitrile solutions were

  4. Magnetic properties of Co-Zr-B magnets produced by spark plasma sintering method

    SciTech Connect (OSTI)

    Saito, Tetsuji, E-mail: tetsuji.saito@it-chiba.ac.jp; Akiyama, Tomoya [Department of Mechanical Science and Engineering, Chiba Institute of Technology, 2-17-1 Tsudanuma, Narashino, Chiba 275-0016 (Japan)

    2014-05-07T23:59:59.000Z

    Magnets of Co-Zr-B, one of the permanent magnetic compounds without rare-earth elements, were successfully produced by the spark plasma sintering method. The resultant Co-Zr-B magnets had high densities of 92%–96% and consisted mainly of the Co{sub x}Zr (x ? 5) phase. The coercivity of the Co-Zr-B magnets was highly dependent on the consolidation temperature and the boron content. The highest maximum energy product of 6.0 MGOe, with a remanence of 6.4 kG and the coercivity of 4.0 kOe, was achieved by the Co{sub 80}Zr{sub 18}B{sub 2} magnets consolidated at 873?K.

  5. The Resistive-WELL detector: a compact spark-protected single amplification-stage MPGD

    E-Print Network [OSTI]

    G. Bencivenni; R. De Oliveira; G. Morello; M. Poli Lener

    2014-11-10T23:59:59.000Z

    In this work we present a novel idea for a compact spark-protected single amplification stage Micro-Pattern Gas Detector (MPGD). The detector amplification stage, realized with a structure very similar to a GEM foil, is embedded through a resistive layer in the readout board. A cathode electrode, defining the gas conversion/drift gap, completes the detector mechanics. The new structure, that we call Resistive-WELL (R-WELL), has some characteristics in common with previous MPGDs, such as C.A.T. and WELL, developed more than ten years ago. The prototype object of the present study has been realized in the 2009 by TE-MPE-EM Workshop at CERN. The new architecture is a very compact MPGD, robust against discharges and exhibiting a large gain ($\\sim$6$\\times$10$^3$), simple to construct and easy for engineering and then suitable for large area tracking devices as well as huge calorimetric apparata.

  6. Experimental Investigation of the Thermal Upset and Recovery of the National Ignition Facility's Optics Module

    SciTech Connect (OSTI)

    J. D. Bernardin

    1999-05-01T23:59:59.000Z

    The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory is being constructed as the latest in a series of high-power laser facilities to study inertial confinement fusion. In particular, the NIF will generate and amplify 192 laser beams and focus them onto a fusion fuel capsule the size of a BB. The energy deposited by the laser beams will raise the core temperature of the target to 100,OOO,OOO C, which will ignite the fusion fuel and produce a fusion energy output that is several times greater than the energy input. The ability to generate, condition, and focus 192 laser beams onto a target the size of a BB, requires precision optical hardware and instrumentation. One of the most critical pieces of optical hardware within the NIF is the Optics Module (OM), a mechanical apparatus which is responsible for optical focusing and frequency conversion of the laser beam to optimize the energy deposition at the fusion target. The OM contains two potassium dihydrogen phosphate (KDP), frequency conversion crystals and a focusing lens. The functionality of the KDP crystals is extremely temperature sensitive. Small temperature changes on the order of 0.1 C can significantly alter the performance of these components. Consequently, to maximize NIF system availability and minimize beam conditioning problems, accurate temperature control of the OM optical components was deemed a necessity. In this study, an experimental OM prototype, containing mock frequency conversion crystals and a focusing lens, was used determine the thermal stability provided by a prototype water temperature control system. More importantly, the OM prototype was used to identify and characterize potential thermal upsets and corresponding recovery times of the KDP crystals. The results of this study indicate that the water temperature control system is adequate in maintaining uniform steady-state temperatures within the OM. Vacuum pump-down and venting of the OM generated significant temperature changes in the optical components. However, the corresponding recovery times of the optical components were found to be less than three hours, well within the seven hour limit posed by NW operations. Simulated laser shots also were found to create thermal upsets within the OM's optical components over a range of heat deposition rates. However, the recovery times of these thermal upsets were found to be less than one hour. Finally, the use of non-contact infrared thermocouples was demonstrated as an effective means to track the temperature of the OM's optics.

  7. Knock mitigation on boosted Controlled Auto-Ignition engines with fuel stratification and Exhaust Gas Recycling

    E-Print Network [OSTI]

    Sang, Wen, Ph. D. Massachusetts Institute of Technology

    2014-01-01T23:59:59.000Z

    This research is carried out to understand the mechanism of using fuel stratification and Exhaust Gas Recycling (EGR) for knock mitigation on boosted Controlled Auto-Ignition (CAl) engines. Experiments were first conducted ...

  8. Tungsten bridge for the low energy ignition of explosive and energetic materials

    DOE Patents [OSTI]

    Benson, D.A.; Bickes, R.W. Jr.; Blewer, R.S.

    1990-12-11T23:59:59.000Z

    A tungsten bridge device for the low energy ignition of explosive and energetic materials is disclosed. The device is fabricated on a silicon-on-sapphire substrate which has an insulating bridge element defined therein using standard integrated circuit fabrication techniques. Then, a thin layer of tungsten is selectively deposited on the silicon bridge layer using chemical vapor deposition techniques. Finally, conductive lands are deposited on each end of the tungsten bridge layer to form the device. It has been found that this device exhibits substantially shorter ignition times than standard metal bridges and foil igniting devices. In addition, substantially less energy is required to cause ignition of the tungsten bridge device of the present invention than is required for common metal bridges and foil devices used for the same purpose. 2 figs.

  9. A new metric of the low-mode asymmetry for ignition target designs

    SciTech Connect (OSTI)

    Gu, Jianfa, E-mail: gu-jianfa@iapcm.ac.cn; Dai, Zhensheng; Fan, Zhengfeng; Zou, Shiyang, E-mail: zou-shiyang@iapcm.ac.cn; Ye, Wenhua; Pei, Wenbing; Zhu, Shaoping [Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China)] [Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China)

    2014-01-15T23:59:59.000Z

    In the deuterium-tritium inertial confinement fusion implosion experiments on the National Ignition Facility, the measured neutron yield and hot spot pressure are significantly lower than simulations. Understanding the underlying physics of the deficit is essential to achieving ignition. This paper investigates the low-mode areal density asymmetry in the main fuel of ignition capsule. It is shown that the areal density asymmetry breaks up the compressed shell and significantly reduces the conversion of implosion kinetic energy to hot spot internal energy, leading to the calculated hot spot pressure and neutron yield quite close to the experimental data. This indicates that the low-mode shell areal density asymmetry can explain part of the large discrepancy between simulations and experiments. Since only using the hot spot shape term could not adequately characterize the effects of the shell areal density asymmetry on implosion performance, a new metric of the low-mode asymmetry is developed to accurately measure the probability of ignition.

  10. Tungsten bridge for the low energy ignition of explosive and energetic materials

    DOE Patents [OSTI]

    Benson, David A. (Albuquerque, NM); Bickes, Jr., Robert W. (Albuquerque, NM); Blewer, Robert S. (Albuquerque, NM)

    1990-01-01T23:59:59.000Z

    A tungsten bridge device for the low energy ignition of explosive and energetic materials is disclosed. The device is fabricated on a silicon-on-sapphire substrate which has an insulating bridge element defined therein using standard integrated circuit fabrication techniques. Then, a thin layer of tungsten is selectively deposited on the silicon bridge layer using chemical vapor deposition techniques. Finally, conductive lands are deposited on each end of the tungsten bridge layer to form the device. It has been found that this device exhibits substantially shorter ignition times than standard metal bridges and foil igniting devices. In addition, substantially less energy is required to cause ignition of the tungsten bridge device of the present invention than is required for common metal bridges and foil devices used for the same purpose.

  11. Extension of the high load limit in the Homogeneous Charge Compression Ignition engine

    E-Print Network [OSTI]

    Scaringe, Robert J. (Robert Joseph)

    2009-01-01T23:59:59.000Z

    The Homogeneous Charge Compression Ignition (HCCI) engine offers diesel-like efficiency with very low soot and NOx emissions. In a HCCI engine, a premixed charge of air, fuel and burned gas is compressed to achieve ...

  12. Method and apparatus for igniting an in situ oil shale retort

    DOE Patents [OSTI]

    Burton, Robert S. (Grand Junction, CO); Rundberg, Sten I. (Debeque, CO); Vaughn, James V. (Debeque, CO); Williams, Thomas P. (Debeque, CO); Benson, Gregory C. (Grand Junction, CO)

    1981-01-01T23:59:59.000Z

    A technique is provided for igniting an in situ oil shale retort having an open void space over the top of a fragmented mass of particles in the retort. A conduit is extended into the void space through a hole in overlying unfragmented formation and has an open end above the top surface of the fragmented mass. A primary air pipe having an open end above the open end of the conduit and a liquid atomizing fuel nozzle in the primary air pipe above the open end of the primary air pipe are centered in the conduit. Fuel is introduced through the nozzle, primary air through the pipe, and secondary air is introduced through the conduit for vortical flow past the open end of the primary air pipe. The resultant fuel and air mixture is ignited for combustion within the conduit and the resultant heated ignition gas impinges on the fragmented mass for heating oil shale to an ignition temperature.

  13. Electron generation and transport in intense relativistic laser-plasma interactions relevant to fast ignition ICF

    E-Print Network [OSTI]

    Ma, Tammy Yee Wing

    2010-01-01T23:59:59.000Z

    Ultra-Short Pulse, Ultra-High In- tensity Lasers . . . . . . . . . . . . . . . . . . . . . . . .ignition), an ultra-intense short pulse laser is brought inof the ultra-high intensity, short-pulse laser has opened up

  14. Ignition Delay Times of Natural Gas/Hydrogen Blends at Elevated Pressures

    E-Print Network [OSTI]

    Brower, Marissa

    2012-10-19T23:59:59.000Z

    Applications of natural gases that contain high levels of hydrogen have become a primary interest in the gas turbine market. For reheat gas turbines, understanding of the ignition delay times of high-hydrogen natural gases is important for two...

  15. On the Fielding of a High Gain, Shock-Ignited Target on the National Ignitiion Facility in the Near Term

    SciTech Connect (OSTI)

    Perkins, L J; Betti, R; Schurtz, G P; Craxton, R S; Dunne, A M; LaFortune, K N; Schmitt, A J; McKenty, P W; Bailey, D S; Lambert, M A; Ribeyre, X; Theobald, W R; Strozzi, D J; Harding, D R; Casner, A; Atzemi, S; Erbert, G V; Andersen, K S; Murakami, M; Comley, A J; Cook, R C; Stephens, R B

    2010-04-12T23:59:59.000Z

    Shock ignition, a new concept for igniting thermonuclear fuel, offers the possibility for a near-term ({approx}3-4 years) test of high gain inertial confinement fusion on the National Ignition Facility at less than 1MJ drive energy and without the need for new laser hardware. In shock ignition, compressed fusion fuel is separately ignited by a strong spherically converging shock and, because capsule implosion velocities are significantly lower than those required for conventional hotpot ignition, fusion energy gains of {approx}60 may be achievable on NIF at laser drive energies around {approx}0.5MJ. Because of the simple all-DT target design, its in-flight robustness, the potential need for only 1D SSD beam smoothing, minimal early time LPI preheat, and use of present (indirect drive) laser hardware, this target may be easier to field on NIF than a conventional (polar) direct drive hotspot ignition target. Like fast ignition, shock ignition has the potential for high fusion yields at low drive energy, but requires only a single laser with less demanding timing and spatial focusing requirements. Of course, conventional symmetry and stability constraints still apply. In this paper we present initial target performance simulations, delineate the critical issues and describe the immediate-term R&D program that must be performed in order to test the potential of a high gain shock ignition target on NIF in the near term.

  16. Ignition properties of n-butane and iso-butane in a rapid compression machine

    SciTech Connect (OSTI)

    Gersen, S.; Darmeveil, J.H. [Gasunie Engineering and Technology, P.O. Box 19, 9700 MA Groningen (Netherlands); Mokhov, A.V. [Laboratory for Fuel and Combustion Science, University of Groningen, Nijenborgh 4, 9747 AG Groningen (Netherlands); Levinsky, H.B. [Gasunie Engineering and Technology, P.O. Box 19, 9700 MA Groningen (Netherlands); Laboratory for Fuel and Combustion Science, University of Groningen, Nijenborgh 4, 9747 AG Groningen (Netherlands)

    2010-02-15T23:59:59.000Z

    Autoignition delay times of n-butane and iso-butane have been measured in a Rapid Compression Machine in the temperature range 660-1010 K, at pressures varying from 14 to 36 bar and at equivalence ratios {phi} = 1.0 and {phi} = 0.5. Both butane isomers exhibit a negative-temperature-coefficient (NTC) region and, at low temperatures, two-stage ignition. At temperatures below {proportional_to}900 K, the delay times for iso-butane are longer than those for the normal isomer, while above this temperature both butanes give essentially the same results. At temperatures above {proportional_to}720 K the delay times of the lean mixtures are twice those for stoichiometric compositions; at T < 720 K, the equivalence ratio is seen to have little influence on the ignition behavior. Increasing the pressure from 15 bar to 30 bar decreases the amplitude of the NTC region, and reduces the ignition delay time for both isomers by roughly a factor of 3. In the region in which two-stage ignition is observed, 680-825 K, the duration of the first ignition stage decreases sharply in the range 680-770 K, but is essentially flat above 770 K. Good quantitative agreement is found between the measurements and calculations for n-butane using a comprehensive model for butane ignition, including both delay times in the two-stage region, with substantial differences being observed for iso-butane, particularly in the NTC region. (author)

  17. Nonlinear Dynamics and Structure Formation in Complex Systems

    E-Print Network [OSTI]

    Zonca, Fulvio

    Condition · In burning plasmas ignition condition is reached when local power density (self-heating the ignition condition (-particle self-heating) #12;Nonlinear Dynamics and Structure Formation in Complex of charged fusion products · -particle self-heating may be lost due to their transport out of the system

  18. Development and Benchmarking of a Hybrid PIC Code For Dense Plasmas and Fast Ignition

    SciTech Connect (OSTI)

    Witherspoon, F. Douglas [HyperV Technologies Corp.; Welch, Dale R. [Voss Scientific, LLC; Thompson, John R. [FAR-TECH, Inc.; MacFarlane, Joeseph J. [Prism Computational Sciences Inc.; Phillips, Michael W. [Advanced Energy Systems, Inc.; Bruner, Nicki [Voss Scientific, LLC; Mostrom, Chris [Voss Scientific, LLC; Thoma, Carsten [Voss Scientific, LLC; Clark, R. E. [Voss Scientific, LLC; Bogatu, Nick [FAR-TECH, Inc.; Kim, Jin-Soo [FAR-TECH, Inc.; Galkin, Sergei [FAR-TECH, Inc.; Golovkin, Igor E. [Prism Computational Sciences, Inc.; Woodruff, P. R. [Prism Computational Sciences, Inc.; Wu, Linchun [HyperV Technologies Corp.; Messer, Sarah J. [HyperV Technologies Corp.

    2014-05-20T23:59:59.000Z

    Radiation processes play an important role in the study of both fast ignition and other inertial confinement schemes, such as plasma jet driven magneto-inertial fusion, both in their effect on energy balance, and in generating diagnostic signals. In the latter case, warm and hot dense matter may be produced by the convergence of a plasma shell formed by the merging of an assembly of high Mach number plasma jets. This innovative approach has the potential advantage of creating matter of high energy densities in voluminous amount compared with high power lasers or particle beams. An important application of this technology is as a plasma liner for the flux compression of magnetized plasma to create ultra-high magnetic fields and burning plasmas. HyperV Technologies Corp. has been developing plasma jet accelerator technology in both coaxial and linear railgun geometries to produce plasma jets of sufficient mass, density, and velocity to create such imploding plasma liners. An enabling tool for the development of this technology is the ability to model the plasma dynamics, not only in the accelerators themselves, but also in the resulting magnetized target plasma and within the merging/interacting plasma jets during transport to the target. Welch pioneered numerical modeling of such plasmas (including for fast ignition) using the LSP simulation code. Lsp is an electromagnetic, parallelized, plasma simulation code under development since 1995. It has a number of innovative features making it uniquely suitable for modeling high energy density plasmas including a hybrid fluid model for electrons that allows electrons in dense plasmas to be modeled with a kinetic or fluid treatment as appropriate. In addition to in-house use at Voss Scientific, several groups carrying out research in Fast Ignition (LLNL, SNL, UCSD, AWE (UK), and Imperial College (UK)) also use LSP. A collaborative team consisting of HyperV Technologies Corp., Voss Scientific LLC, FAR-TECH, Inc., Prism Computational Sciences, Inc. and Advanced Energy Systems Inc. joined efforts to develop new physics and numerical models for LSP in several key areas to enhance the ability of LSP to model high energy density plasmas (HEDP). This final report details those efforts. Areas addressed in this research effort include: adding radiation transport to LSP, first in 2D and then fully 3D, extending the EMHD model to 3D, implementing more advanced radiation and electrode plasma boundary conditions, and installing more efficient implicit numerical algorithms to speed complex 2-D and 3-D computations. The new capabilities allow modeling of the dominant processes in high energy density plasmas, and further assist the development and optimization of plasma jet accelerators, with particular attention to MHD instabilities and plasma/wall interaction (based on physical models for ion drag friction and ablation/erosion of the electrodes). In the first funding cycle we implemented a solver for the radiation diffusion equation. To solve this equation in 2-D, we used finite-differencing and applied the parallelized sparse-matrix solvers in the PETSc library (Argonne National Laboratory) to the resulting system of equations. A database of the necessary coefficients for materials of interest was assembled using the PROPACEOS and ATBASE codes from Prism. The model was benchmarked against Prism's 1-D radiation hydrodynamics code HELIOS, and against experimental data obtained from HyperV's separately funded plasma jet accelerator development program. Work in the second funding cycle focused on extending the radiation diffusion model to full 3-D, continued development of the EMHD model, optimizing the direct-implicit model to speed up calculations, add in multiply ionized atoms, and improved the way boundary conditions are handled in LSP. These new LSP capabilities were then used, along with analytic calculations and Mach2 runs, to investigate plasma jet merging, plasma detachment and transport, restrike and advanced jet accelerator design. In addition, a strong linkage to diagnostic measureme

  19. Dynamic control of a homogeneous charge compression ignition engine

    DOE Patents [OSTI]

    Duffy, Kevin P. (Metamora, IL); Mehresh, Parag (Peoria, IL); Schuh, David (Peoria, IL); Kieser, Andrew J. (Morton, IL); Hergart, Carl-Anders (Peoria, IL); Hardy, William L. (Peoria, IL); Rodman, Anthony (Chillicothe, IL); Liechty, Michael P. (Chillicothe, IL)

    2008-06-03T23:59:59.000Z

    A homogenous charge compression ignition engine is operated by compressing a charge mixture of air, exhaust and fuel in a combustion chamber to an autoignition condition of the fuel. The engine may facilitate a transition from a first combination of speed and load to a second combination of speed and load by changing the charge mixture and compression ratio. This may be accomplished in a consecutive engine cycle by adjusting both a fuel injector control signal and a variable valve control signal away from a nominal variable valve control signal. Thereafter in one or more subsequent engine cycles, more sluggish adjustments are made to at least one of a geometric compression ratio control signal and an exhaust gas recirculation control signal to allow the variable valve control signal to be readjusted back toward its nominal variable valve control signal setting. By readjusting the variable valve control signal back toward its nominal setting, the engine will be ready for another transition to a new combination of engine speed and load.

  20. Method for fabricating an ignitable heterogeneous stratified metal structure

    DOE Patents [OSTI]

    Barbee, T.W. Jr.; Weihs, T.

    1996-08-20T23:59:59.000Z

    A multilayer structure has a selectable: (1) propagating reaction front velocity V; (2) reaction initiation temperature attained by application of external energy; and (3) amount of energy delivered by a reaction of alternating unreacted layers of the multilayer structure. Because V is selectable and controllable, a variety of different applications for the multilayer structures are possible, including but not limited to their use as igniters, in joining applications, in fabrication of new materials, as smart materials and in medical applications and devices. The multilayer structure has a period D, and an energy release rate constant K. Two or more alternating unreacted layers are made of different materials and separated by reacted zones. The period D is equal to a sum of the widths of each single alternating reaction layer of a particular material, and also includes a sum of reacted zone widths, t{sub i}, in the period D. The multilayer structure has a selectable propagating reaction front velocity V, where V=K(1/D{sup n}){times}[1-(t{sub i}/D)] and n is about 0.8 to 1.2. 8 figs.

  1. Nuclear imaging of the fuel assembly in ignition experiments

    SciTech Connect (OSTI)

    Grim, G. P.; Guler, N.; Merrill, F. E.; Morgan, G. L.; Danly, C. R.; Volegov, P. L.; Wilde, C. H.; Wilson, D. C.; Batha, S.; Herrmann, H. W.; Kline, J. L.; Kyrala, G. A. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Clark, D. S.; Hinkel, D. E.; Jones, O. S.; Raman, K. S.; Izumi, N.; Fittinghoff, D. N.; Drury, O. B.; Alger, E. T. [Lawrence Livermore National Laboratory, Livermore, California 94551-0808 (United States)] [Lawrence Livermore National Laboratory, Livermore, California 94551-0808 (United States); and others

    2013-05-15T23:59:59.000Z

    First results from the analysis of neutron image data collected on implosions of cryogenically layered deuterium-tritium capsules during the 2011-2012 National Ignition Campaign are reported. The data span a variety of experimental designs aimed at increasing the stagnation pressure of the central hotspot and areal density of the surrounding fuel assembly. Images of neutrons produced by deuterium–tritium fusion reactions in the hotspot are presented, as well as images of neutrons that scatter in the surrounding dense fuel assembly. The image data are compared with 1D and 2D model predictions, and consistency checked using other diagnostic data. The results indicate that the size of the fusing hotspot is consistent with the model predictions, as well as other imaging data, while the overall size of the fuel assembly, inferred from the scattered neutron images, is systematically smaller than models' prediction. Preliminary studies indicate these differences are consistent with a significant fraction (20%–25%) of the initial deuterium-tritium fuel mass outside the compact fuel assembly, due either to low mode mass asymmetry or high mode 3D mix effects at the ablator-ice interface.

  2. Preliminary hazards analysis for the National Ignition Facility

    SciTech Connect (OSTI)

    Brereton, S.J.

    1993-10-01T23:59:59.000Z

    This report documents the Preliminary Hazards Analysis (PHA) for the National Ignition Facility (NIF). In summary, it provides: a general description of the facility and its operation; identification of hazards at the facility; and details of the hazards analysis, including inventories, bounding releases, consequences, and conclusions. As part of the safety analysis procedure set forth by DOE, a PHA must be performed for the NIF. The PHA characterizes the level of intrinsic potential hazard associated with a facility, and provides the basis for hazard classification. The hazard classification determines the level of safety documentation required, and the DOE Order governing the safety analysis. The hazard classification also determines the level of review and approval required for the safety analysis report. The hazards of primary concern associated with NIF are radiological and toxicological in nature. The hazard classification is determined by comparing facility inventories of radionuclides and chemicals with threshold values for the various hazard classification levels and by examining postulated bounding accidents associated with the hazards of greatest significance. Such postulated bounding accidents cannot take into account active mitigative features; they must assume the unmitigated consequences of a release, taking into account only passive safety features. In this way, the intrinsic hazard level of the facility can be ascertained.

  3. SolarBridge Technologies formerly SmartSpark Energy Systems | Open Energy

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to:Ezfeedflag JumpID-f < RAPID‎

  4. STATEMENT OF CONSIDERATIONS REQUEST BY GENERAL MOTORS CORPORATION...

    Broader source: Energy.gov (indexed) [DOE]

    for the performance of work entitled, "Development of High Efficiency Clean Combustion Engine Designs for Spark Ignition and Compression Ignition Internal Combustion Engines." The...

  5. A shock tube study of iso-octane ignition at elevated pressures: The influence of diluent gases

    SciTech Connect (OSTI)

    Shen, Hsi-Ping S.; Vanderover, Jeremy; Oehlschlaeger, Matthew A. [Department of Mechanical, Aerospace, and Nuclear Engineering, Rensselaer Polytechnic Institute, 110 Eighth Street, JEC 2049, Troy, NY 12180 (United States)

    2008-12-15T23:59:59.000Z

    The ignition of iso-octane/air and iso-octane/O{sub 2}/Ar ({proportional_to}20% O{sub 2}) mixtures was studied in a shock tube at temperatures of 868-1300 K, pressures of 7-58 atm, and equivalence ratios {phi}=1.0, 0.5, and 0.25. Ignition times were determined using endwall OH* emission and sidewall piezoelectric pressure measurements. Measured iso-octane/air ignition times agreed well with the previously published results. Mixtures with argon as the diluent exhibited ignition times 20% shorter, for most conditions, than those with nitrogen as the diluent (iso-octane/air mixtures). The difference in measured ignition times for mixtures containing argon and nitrogen as the diluent gas can be attributed to the differing heat capacities of the two diluent species and the level of induction period heat release prior to ignition. Kinetic model predictions of ignition time from three mechanisms are compared to the experimental data. The mechanisms overpredict the ignition times but accurately capture the influence of diluent gas on iso-octane ignition time, indicating that the mechanisms predict an appropriate amount of induction period heat release. (author)

  6. Advances in Inertial Confinement Fusion at the National Ignition Facility (NIF)

    SciTech Connect (OSTI)

    Moses, E

    2009-10-15T23:59:59.000Z

    The 192-beam National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory (LLNL) in Livermore, CA, is now operational and conducting experiments. NIF, the flagship facility of the U.S. Inertial Confinement Fusion (ICF) Program, will achieve high-energy-density conditions never previously obtained in the laboratory - temperatures over 100 million K, densities of 1,000 g/cm3, and pressures exceeding 100 billion atmospheres. Such conditions exist naturally only in the interiors of the stars and during thermonuclear burn. Demonstration of ignition and thermonuclear burn in the laboratory is a major NIF goal. To date, the NIF laser has demonstrated all pulse shape, beam quality, energy, and other specifications required to meet the ignition challenge. On March 10, 2009, the NIF laser delivered 1.1 MJ of ultraviolet laser energy to target chamber center, approximately 30 times more energy than any previous facility. The ignition program at NIF is the National Ignition Campaign (NIC), a national collaboration for ignition experimentation with participation from General Atomics, LLNL, Los Alamos National Laboratory (LANL), Sandia National Laboratories (SNL), and the University of Rochester Laboratory for Laser Energetics (LLE). The achievement of ignition at NIF will demonstrate the scientific feasibility of ICF and focus worldwide attention on fusion as a viable energy option. A particular energy concept under investigation is the LIFE (Laser Inertial Fusion Energy) scheme. The LIFE engine is inherently safe, minimizes proliferation concerns associated with the nuclear fuel cycle, and can provide a sustainable carbon-free energy generation solution in the 21st century. This talk will describe NIF and its potential as a user facility and an experimental platform for high-energy-density science, NIC, and the LIFE approach for clean, sustainable energy.

  7. A geophysical shock and air blast simulator at the National Ignition Facility

    SciTech Connect (OSTI)

    Fournier, K. B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Brown, C. G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); May, M. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Compton, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Walton, O. R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Shingleton, N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kane, J. O. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Holtmeier, G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Loey, H. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Mirkarimi, P. B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Dunlop, W. H. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Guyton, R. L. [National Security Technologies, Livermore, CA (United States); Huffman, E. [National Security Technologies, Livermore, CA (United States)

    2014-09-01T23:59:59.000Z

    The energy partitioning energy coupling experiments at the National Ignition Facility (NIF) have been designed to measure simultaneously the coupling of energy from a laser-driven target into both ground shock and air blast overpressure to nearby media. The source target for the experiment is positioned at a known height above the ground-surface simulant and is heated by four beams from the NIF. The resulting target energy density and specific energy are equal to those of a low-yield nuclear device. The ground-shock stress waves and atmospheric overpressure waveforms that result in our test system are hydrodynamically scaled analogs of full-scale seismic and air blast phenomena. This report summarizes the development of the platform, the simulations, and calculations that underpin the physics measurements that are being made, and finally the data that were measured. Agreement between the data and simulation of the order of a factor of two to three is seen for air blast quantities such as peak overpressure. Historical underground test data for seismic phenomena measured sensor displacements; we measure the stresses generated in our ground-surrogate medium. We find factors-of-a-few agreement between our measured peak stresses and predictions with modern geophysical computer codes.

  8. A geophysical shock and air blast simulator at the National Ignition Facility

    SciTech Connect (OSTI)

    Fournier, K. B.; Brown, C. G.; May, M. J.; Compton, S.; Walton, O. R.; Shingleton, N.; Kane, J. O.; Holtmeier, G.; Loey, H.; Mirkarimi, P. B.; Dunlop, W. H. [Lawrence Livermore National Laboratory, P.O. Box 808, L-481, Livermore, California 94550 (United States); Guyton, R. L.; Huffman, E. [National Securities Technologies, Vasco Rd., Livermore, California 94551 (United States)

    2014-09-15T23:59:59.000Z

    The energy partitioning energy coupling experiments at the National Ignition Facility (NIF) have been designed to measure simultaneously the coupling of energy from a laser-driven target into both ground shock and air blast overpressure to nearby media. The source target for the experiment is positioned at a known height above the ground-surface simulant and is heated by four beams from the NIF. The resulting target energy density and specific energy are equal to those of a low-yield nuclear device. The ground-shock stress waves and atmospheric overpressure waveforms that result in our test system are hydrodynamically scaled analogs of full-scale seismic and air blast phenomena. This report summarizes the development of the platform, the simulations, and calculations that underpin the physics measurements that are being made, and finally the data that were measured. Agreement between the data and simulation of the order of a factor of two to three is seen for air blast quantities such as peak overpressure. Historical underground test data for seismic phenomena measured sensor displacements; we measure the stresses generated in our ground-surrogate medium. We find factors-of-a-few agreement between our measured peak stresses and predictions with modern geophysical computer codes.

  9. Effect of temperature and time on properties of Spark Plasma Sintered NiCuZn: Co ferrite

    E-Print Network [OSTI]

    Effect of temperature and time on properties of Spark Plasma Sintered NiCuZn: Co ferrite K. Zehani hundred MHz, and a high resistivity, but the conventional sintering temperature is too high for co. EXPERIMENTAL: Powders of basic oxides Fe2O3, NiO, CuO and ZnO and Co2O3 were used for the preparation of Ni

  10. Gasoline surrogate modeling of gasoline ignition in a rapid compression machine and comparison to experiments

    SciTech Connect (OSTI)

    Mehl, M; Kukkadapu, G; Kumar, K; Sarathy, S M; Pitz, W J; Sung, S J

    2011-09-15T23:59:59.000Z

    The use of gasoline in homogeneous charge compression ignition engines (HCCI) and in duel fuel diesel - gasoline engines, has increased the need to understand its compression ignition processes under engine-like conditions. These processes need to be studied under well-controlled conditions in order to quantify low temperature heat release and to provide fundamental validation data for chemical kinetic models. With this in mind, an experimental campaign has been undertaken in a rapid compression machine (RCM) to measure the ignition of gasoline mixtures over a wide range of compression temperatures and for different compression pressures. By measuring the pressure history during ignition, information on the first stage ignition (when observed) and second stage ignition are captured along with information on the phasing of the heat release. Heat release processes during ignition are important because gasoline is known to exhibit low temperature heat release, intermediate temperature heat release and high temperature heat release. In an HCCI engine, the occurrence of low-temperature and intermediate-temperature heat release can be exploited to obtain higher load operation and has become a topic of much interest for engine researchers. Consequently, it is important to understand these processes under well-controlled conditions. A four-component gasoline surrogate model (including n-heptane, iso-octane, toluene, and 2-pentene) has been developed to simulate real gasolines. An appropriate surrogate mixture of the four components has been developed to simulate the specific gasoline used in the RCM experiments. This chemical kinetic surrogate model was then used to simulate the RCM experimental results for real gasoline. The experimental and modeling results covered ultra-lean to stoichiometric mixtures, compressed temperatures of 640-950 K, and compression pressures of 20 and 40 bar. The agreement between the experiments and model is encouraging in terms of first-stage (when observed) and second-stage ignition delay times and of heat release rate. The experimental and computational results are used to gain insight into low and intermediate temperature processes during gasoline ignition.

  11. Experiments and Analysis of High Cyclic Variability at the Operational Limits of Spark-Assisted HCCI Combustion

    E-Print Network [OSTI]

    Stefanopoulou, Anna

    -Assisted HCCI Combustion Jacob Larimore, Erik Hellstr¨om, Jeff Sterniak, Li Jiang, Anna G. Stefanopoulou Abstract-- During combustion mode switches, between ho- mogeneous charge compression ignition (HCCI at the high CV condition we perform measurements on a four-cylinder HCCI engine with negative valve overlap

  12. Simulations of laser imprint for Nova experiments and for ignition capsules. Revision 1

    SciTech Connect (OSTI)

    Weber, S.V.; Glendinning, S.G.; Kalantar, D.H.; Key, M.H.; Remington, B.A.; Rothenberg, J.L. [Lawrence Livermore National Lab., CA (United States); Wolfrum, E. [Rutherford Appleton Lab., Chilton (United Kingdom); Verdon, C.P.; Knauer, J.P. [Rochester Univ., NY (United States). Lab. for Laser Energetics

    1996-12-01T23:59:59.000Z

    In direct drive ICF, nonuniformities in laser illumination seed ripples at the ablation front in a process called ``imprint``. These nonuniformities grow during the capsule implosion and, if initially large enough, can penetrate the capsule shell, impede ignition, or degrade burn. Imprint has been simulated for recent experiments performed on the Nova laser at LLNL examining a variety of beam smoothing conditions. Most used laser intensities similar to the early part of an ignition capsule pulse shape, 1 {approx_equal} 10{sup 13} W/cm{sup 2} . The simulations matched most of the measurements of imprint modulation. The effect of imprint upon National Ignition Facility (NIF) direct drive ignition capsules has also been simulated. Imprint is predicted to give modulation comparable to an intrinsic surface finish of {approximately}10 nm RMS. Modulation growth was examined using the Haan [Phys. Rev. A {bold 39}, 5812 (1989)] model, with linear growth factors as a function of spherical harmonic mode number obtained from an analytic dispersion relation. Ablation front amplitudes are predicted to become substantially nonlinear, so that saturation corrections are large. Direct numerical simulations of two-dimensional multimode growth were also performed. The capsule shell is predicted to remain intact, which gives a basis for believing that ignition can be achieved. 27 refs., 10 figs.

  13. Simulations of laser imprint for Nova experiments and for ignition capsules

    SciTech Connect (OSTI)

    Weber, S.V.; Glendinning, S.G.; Kalantar, D.H.; Key, M.H.; Remington, B.A.; Rothenberg, J.E.; Wolfrum, E.; Verdon, C.P.; Knauer, J.P.

    1996-11-08T23:59:59.000Z

    In direct drive ICF, nonuniformities in laser illumination seed ripples at the ablation front in a process called imprint. These non nonuniformities grow during the capsule implosion and, if initially large enough, can penetrate the capsule shell, impede ignition, or degrade burn. Imprint has been simulated for recent experiments performed on the Nova laser at LLNL examining a variety of beam smoothing conditions. Most used laser intensities similar to the early part of an ignition capsule pulse shape, I=10X13 W/cm3. The simulations matched most of the measurements of imprint modulation. The effect of imprint upon National Ignition Facility (NIF) direct drive ignition capsules has also been simulated. Imprint is predicted to give modulation comparable to an intrinsic surface finish of 10 nm RMS. Modulation growth was examined using the Haan model, with linear growth as a function of spherical harmonic mode number obtained from an analytic dispersion relation. Ablation front amplitudes are predicted to become substantially nonlinear, so that saturation corrections are large. Direct numerical simulations of two- dimensional multimode growth were also performed. The capsule shell is predicted to remain intact, which gives a basis for believing that ignition can be achieved.

  14. Progress in hohlraum physics for the National Ignition Facility

    SciTech Connect (OSTI)

    Moody, J. D., E-mail: moody4@llnl.gov; Callahan, D. A.; Hinkel, D. E.; Amendt, P. A.; Baker, K. L.; Bradley, D.; Celliers, P. M.; Dewald, E. L.; Divol, L.; Döppner, T.; Eder, D. C.; Edwards, M. J.; Jones, O.; Haan, S. W.; Ho, D.; Hopkins, L. B.; Izumi, N.; Kalantar, D.; Kauffman, R. L.; Kilkenny, J. D. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); and others

    2014-05-15T23:59:59.000Z

    Advances in hohlraums for inertial confinement fusion at the National Ignition Facility (NIF) were made this past year in hohlraum efficiency, dynamic shape control, and hot electron and x-ray preheat control. Recent experiments are exploring hohlraum behavior over a large landscape of parameters by changing the hohlraum shape, gas-fill, and laser pulse. Radiation hydrodynamic modeling, which uses measured backscatter, shows that gas-filled hohlraums utilize between 60% and 75% of the laser power to match the measured bang-time, whereas near-vacuum hohlraums utilize 98%. Experiments seem to be pointing to deficiencies in the hohlraum (instead of capsule) modeling to explain most of the inefficiency in gas-filled targets. Experiments have begun quantifying the Cross Beam Energy Transfer (CBET) rate at several points in time for hohlraum experiments that utilize CBET for implosion symmetry. These measurements will allow better control of the dynamic implosion symmetry for these targets. New techniques are being developed to measure the hot electron energy and energy spectra generated at both early and late time. Rugby hohlraums offer a target which requires little to no CBET and may be less vulnerable to undesirable dynamic symmetry “swings.” A method for detecting the effect of the energetic electrons on the fuel offers a direct measure of the hot electron effects as well as a means to test energetic electron mitigation methods. At higher hohlraum radiation temperatures (including near vacuum hohlraums), the increased hard x-rays (1.8–4?keV) may pose an x-ray preheat problem. Future experiments will explore controlling these x-rays with advanced wall materials.

  15. Homogenous charge compression ignition engine having a cylinder including a high compression space

    DOE Patents [OSTI]

    Agama, Jorge R.; Fiveland, Scott B.; Maloney, Ronald P.; Faletti, James J.; Clarke, John M.

    2003-12-30T23:59:59.000Z

    The present invention relates generally to the field of homogeneous charge compression engines. In these engines, fuel is injected upstream or directly into the cylinder when the power piston is relatively close to its bottom dead center position. The fuel mixes with air in the cylinder as the power piston advances to create a relatively lean homogeneous mixture that preferably ignites when the power piston is relatively close to the top dead center position. However, if the ignition event occurs either earlier or later than desired, lowered performance, engine misfire, or even engine damage, can result. Thus, the present invention divides the homogeneous charge between a controlled volume higher compression space and a lower compression space to better control the start of ignition.

  16. Apparatus and method for igniting an in situ oil shale retort

    DOE Patents [OSTI]

    Chambers, Carlon C. (Grand Junction, CO)

    1981-01-01T23:59:59.000Z

    A method and apparatus for conducting such method are disclosed for igniting a fragmented permeable mass of formation particles in an in situ oil shale retort. The method is conducted by forming a hole through unfragmented formation to the fragmented mass. An oxygen-containing gas is introduced into the hole. A fuel is introduced into a portion of the hole spaced apart from the fragmented mass. The fuel and oxygen-containing gas mix forming a combustible mixture which is ignited for establishing a combustion zone in a portion of the hole spaced apart from the fragmented mass. The hot gas generated in the combustion zone is conducted from the hole into the fragmented mass for heating a portion of the fragmented mass above an ignition temperature of oil shale.

  17. Report from the Integrated Modeling Panel at the Workshop on the Science of Ignition on NIF

    SciTech Connect (OSTI)

    Marinak, M; Lamb, D

    2012-07-03T23:59:59.000Z

    This section deals with multiphysics radiation hydrodynamics codes used to design and simulate targets in the ignition campaign. These topics encompass all the physical processes they model, and include consideration of any approximations necessary due to finite computer resources. The section focuses on what developments would have the highest impact on reducing uncertainties in modeling most relevant to experimental observations. It considers how the ICF codes should be employed in the ignition campaign. This includes a consideration of how the experiments can be best structured to test the physical models the codes employ.

  18. Confinement requirements for ohmic-compressive ignition of a Spheromak plasma

    SciTech Connect (OSTI)

    Olson, R.E.; Miley, G.H.

    1981-01-01T23:59:59.000Z

    The Moving Plasmoid Reactor (MPR) is an attractive alternative magnetic fusion scheme in which Spheromak plasmoids are envisioned to be formed, compressed, burned, and expanded as the plasmoids translate through a series of linear reactor modules. Although auxiliary heating of the plasmoids may be possible, the MPR scenario would be especially interesting if ohmic decay and compression alone is sufficient to heat the plasmoids to an ignition temperature. In the present work, we examine the transport conditions under which a Spheromak plasmoid can be expected to reach ignition via a combination of ohmic and compression heating.

  19. Fuel mixture stratification as a method for improving homogeneous charge compression ignition engine operation

    SciTech Connect (OSTI)

    Dec, John E. (Livermore, CA); Sjoberg, Carl-Magnus G. (Livermore, CA)

    2006-10-31T23:59:59.000Z

    A method for slowing the heat-release rate in homogeneous charge compression ignition ("HCCI") engines that allows operation without excessive knock at higher engine loads than are possible with conventional HCCI. This method comprises injecting a fuel charge in a manner that creates a stratified fuel charge in the engine cylinder to provide a range of fuel concentrations in the in-cylinder gases (typically with enough oxygen for complete combustion) using a fuel with two-stage ignition fuel having appropriate cool-flame chemistry so that regions of different fuel concentrations autoignite sequentially.

  20. Semiconductor bridge, SCB, ignition studies of Al/CuO thermite

    SciTech Connect (OSTI)

    Bickes, R.W. Jr.; Wackerbarth, D.E. [Sandia National Labs., Albuquerque, NM (United States); Mohler, J.H. [Energetic Materials Associates, Inc., Vero Beach, FL (United States)

    1997-04-01T23:59:59.000Z

    The authors briefly summarize semiconductor bridge operation and review their ignition studies of Al/CuO thermite as a function of the capacitor discharge unit (CDU) firing set capacitance, charge holder material and morphology of the CuO. Ignition thresholds were obtained using a brass charge holder and a non-conducting fiber-glass-epoxy composite material, G10. At - 18 C and a charge voltage of 50V, the capacitance thresholds were 30.1 {mu}F and 2.0 {mu}F respectively. They also present new data on electrostatic discharge (ESD) and radio frequency (RF) vulnerability tests.

  1. IEEE TRANSACTIONS ON CONTROL SYSTEMS TECHNOLOGY 1 Cyclic Variability and Dynamical Instabilities in

    E-Print Network [OSTI]

    Stefanopoulou, Anna

    by autoignition in homogeneous charge compression ignition (HCCI) engines with large amounts of residual gases. Index Terms--Internal combustion engines, nonlinear dynam- ical systems, Gaussian noise, stability on autoignition of a homogeneous mixture. This combustion mode is called homogeneous charge compression ignition

  2. Use of plasma fuel systems at thermal power plants in Russia, Kazakhstan, China, and Turkey

    SciTech Connect (OSTI)

    Karpenko, E.I.; Karpenko, Y.E.; Messerle, V.E.; Ustimenko, A.B. [Russian Academy of Sciences, Ulan Ude (Russian Federation). Institute of Thermal Physics

    2009-05-15T23:59:59.000Z

    The technology of plasma ignition of solid fuels is described, as well as its creation and development steps, the technoeconomic characteristics of plasma igniter systems, schemes of their installation in pulverized-coal boilers, and results of their application at pulverized coal-fired power plants.

  3. Two-dimensional simulations of thermonuclear burn in ignition-scale inertial confinement fusion targets under compressed axial magnetic fields

    SciTech Connect (OSTI)

    Perkins, L. J.; Logan, B. G.; Zimmerman, G. B.; Werner, C. J. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)] [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    2013-07-15T23:59:59.000Z

    We report for the first time on full 2-D radiation-hydrodynamic implosion simulations that explore the impact of highly compressed imposed magnetic fields on the ignition and burn of perturbed spherical implosions of ignition-scale cryogenic capsules. Using perturbations that highly convolute the cold fuel boundary of the hotspot and prevent ignition without applied fields, we impose initial axial seed fields of 20–100 T (potentially attainable using present experimental methods) that compress to greater than 4 × 10{sup 4} T (400 MG) under implosion, thereby relaxing hotspot areal densities and pressures required for ignition and propagating burn by ?50%. The compressed field is high enough to suppress transverse electron heat conduction, and to allow alphas to couple energy into the hotspot even when highly deformed by large low-mode amplitudes. This might permit the recovery of ignition, or at least significant alpha particle heating, in submarginal capsules that would otherwise fail because of adverse hydrodynamic instabilities.

  4. Light Water Reactor Safety Research Program. Semiannual report, October 1982-March 1983. [Molten fuel/concrete interaction; core melt-coolant interaction; hydrogen detonation (Grand Gulf igniter)

    SciTech Connect (OSTI)

    Berman, M.

    1984-05-01T23:59:59.000Z

    The Molten Fuel/Concrete Interactions (MFCI) Study investigates the mechanism of concrete erosion by molten core materials, the nature and rate of generation of evolved gases, and the effects on fission product release. The Core Melt/Coolant Interactions (CMCI) Study investigates the characteristics of explosive and nonexplosive interactions between molten core materials and concrete, and the probabilities and consequences of such interactions. In the Hydrogen Program, the HECTR code for modelling hydrogen deflagration is being developed, experiments (including those in the FITS facility) are being conducted, and the Grand Gulf Hydrogen Igniter System II is being reviewed. All activities are continuing.

  5. Energy Research and Development Division FINAL PROJECT REPORT

    E-Print Network [OSTI]

    · Transportation Improving Efficiency of SparkIgnited, Stoichiometrically Operated Natural Gas Engines OF SPARK IGNITED, STOICHIOMETRICALLY OPERATED NATURAL GAS ENGINES MARCH 2013 CEC5002013103 Prepared for is the final report for the Improving Efficiency Of SparkIgnited, Stoichiometric Operated Natural Gas Engine

  6. Time-resolved measurements of the hot-electron population in ignition-scale experiments on the National Ignition Facility (invited)

    SciTech Connect (OSTI)

    Hohenberger, M., E-mail: mhoh@lle.rochester.edu; Stoeckl, C. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Albert, F.; Palmer, N. E.; Döppner, T.; Divol, L.; Dewald, E. L.; Bachmann, B.; MacPhee, A. G.; LaCaille, G.; Bradley, D. K. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Lee, J. J. [National Security Technologies LLC, Livermore, California 94551 (United States)

    2014-11-15T23:59:59.000Z

    In laser-driven inertial confinement fusion, hot electrons can preheat the fuel and prevent fusion-pellet compression to ignition conditions. Measuring the hot-electron population is key to designing an optimized ignition platform. The hot electrons in these high-intensity, laser-driven experiments, created via laser-plasma interactions, can be inferred from the bremsstrahlung generated by hot electrons interacting with the target. At the National Ignition Facility (NIF) [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 43, 2841 (2004)], the filter-fluorescer x-ray (FFLEX) diagnostic–a multichannel, hard x-ray spectrometer operating in the 20–500 keV range–has been upgraded to provide fully time-resolved, absolute measurements of the bremsstrahlung spectrum with ?300 ps resolution. Initial time-resolved data exhibited significant background and low signal-to-noise ratio, leading to a redesign of the FFLEX housing and enhanced shielding around the detector. The FFLEX x-ray sensitivity was characterized with an absolutely calibrated, energy-dispersive high-purity germanium detector using the high-energy x-ray source at NSTec Livermore Operations over a range of K-shell fluorescence energies up to 111 keV (U K{sub ?}). The detectors impulse response function was measured in situ on NIF short-pulse (?90 ps) experiments, and in off-line tests.

  7. Burner control system

    SciTech Connect (OSTI)

    Cade, P.J.

    1981-01-06T23:59:59.000Z

    A burner control apparatus for use with a furnace installation that has an operating control to produce a request for burner operation, a flame sensor to produce a signal when flame is present in the monitored combustion chamber, and one or more devices for control of ignition and/or fuel flow. The burner control apparatus comprises lockout apparatus for de-energizing the control apparatus, a control device for actuating the ignition and/or fuel control devices, and a timing circuit that provides four successive and partially overlapping timing intervals of precise relation, including a purge timing interval, a pilot ignition interval, and a main fuel ignition interval. The present invention further includes a burner control system which verifies the proper operation of certain sensors in a burner or furnace including particularly the air flow sensor. Additionally, the present system also prevents an attempt to ignite a burner if a condition is detected which indicates that the air flow sensor has been bypassed or wedged in the actuated position.

  8. Application of Pulse Spark Discharges for Scale Prevention and Continuous Filtration Methods in Coal-Fired Power Plant

    SciTech Connect (OSTI)

    Cho, Young; Fridman, Alexander

    2012-06-30T23:59:59.000Z

    The overall objective of the present work was to develop a new scale-prevention technology by continuously precipitating and removing dissolved mineral ions (such as calcium and magnesium) in cooling water while the COC could be doubled from the present standard value of 3.5. The hypothesis of the present study was that if we could successfully precipitate and remove the excess calcium ions in cooling water, we could prevent condenser-tube fouling and at the same time double the COC. The approach in the study was to utilize pulse spark discharges directly in water to precipitate dissolved mineral ions in recirculating cooling water into relatively large suspended particles, which could be removed by a self-cleaning filter. The present study began with a basic scientific research to better understand the mechanism of pulse spark discharges in water and conducted a series of validation experiments using hard water in a laboratory cooling tower. Task 1 of the present work was to demonstrate if the spark discharge could precipitate the mineral ions in water. Task 2 was to demonstrate if the selfcleaning filter could continuously remove these precipitated calcium particles such that the blowdown could be eliminated or significantly reduced. Task 3 was to demonstrate if the scale could be prevented or minimized at condenser tubes with a COC of 8 or (almost) zero blowdown. In Task 1, we successfully completed the validation study that confirmed the precipitation of dissolved calcium ions in cooling water with the supporting data of calcium hardness over time as measured by a calcium ion probe. In Task 2, we confirmed through experimental tests that the self-cleaning filter could continuously remove precipitated calcium particles in a simulated laboratory cooling tower such that the blowdown could be eliminated or significantly reduced. In addition, chemical water analysis data were obtained which were used to confirm the COC calculation. In Task 3, we conducted a series of heat transfer fouling tests using a condenser heat exchanger in the laboratory cooling tower, from which we confirmed that the plasma water treatment technology could prevent or significantly mitigate mineral foulings in condenser tubes when compared with the no-treatment case. With the completion of the present work, a cooling water treatment technology using pulse spark discharges is currently ready for field-validation tests. The plasma water treatment technology is a true mechanical water softener with almost no maintenance, which continuously converts hard water to soft water spending a relatively small amount of energy. Such a mechanical water softener could find wide-spread applications to solve hard water problems both in industry and at home.

  9. Thermoelectric transport properties of polycrystalline titanium diselenide co-intercalated with nickel and titanium using spark plasma sintering

    SciTech Connect (OSTI)

    Holgate, T.C. [Department of Energy Storage and Conversion, Technical University of Denmark, Riso Campus, 4000 Roskilde (Denmark); Zhu, S.; Zhou, M. [Department of Physics and Astronomy, Clemson University, Clemson, SC 29634 (United States); Bangarigadu-Sanasy, S.; Kleinke, H. [Department of Chemistry, University of Waterloo, Waterloo, Ontario, N2L 3G1 (Canada); He, J. [Department of Physics and Astronomy, Clemson University, Clemson, SC 29634 (United States); Tritt, T.M., E-mail: ttritt@clemson.edu [Department of Physics and Astronomy, Clemson University, Clemson, SC 29634 (United States)

    2013-01-15T23:59:59.000Z

    Polycrystalline samples of nickel intercalated (0-5%) TiSe{sub 2} were attempted via solid-state reaction in evacuated quartz tubes followed by densification using a spark plasma sintering process. X-ray diffraction data indicated that mixed NiSe{sub 2} and TiSe{sub 2} phases were present after initial synthesis by solid-state reaction, but a pure TiSe{sub 2} phase was present after the spark plasma sintering. While EPMA data reveals the stoichiometry to be near 1:1.8 (Ti:Se) for all samples, comparisons of the measured bulk densities to the theoretical densities suggest that the off stoichiometry is a result of the co-intercalation of both Ni and Ti rather than Se vacancies. Due to the presence of excess Ti (0.085-0.130 per formula) in the van der Waals gap of all the samples, the sensitive electron-hole balance is offset by the additional Ti-3d electrons, leading to an increase in the thermopower (n-type) over pristine, stoichiometric TiSe{sub 2}. The effects of the co-intercalation of both Ni and Ti in TiSe{sub 2} on the structural, thermal, and electrical properties are discussed herein. - Graphical abstract: Co-intercalation of nickel and excess titanium into the van der Waals gap of TiSe{sub 2} via solid state synthesis followed by spark plasma sintering results in a systematic shift in the ratio of hole and electron carrier concentration, which is close to unity for pristine TiSe{sub 2}. This directly affects the electrical transport properties, and as the structural disorder induced by intercalation suppresses the lattice thermal conductivity, co-intercalation is an effective route to enhance the thermoelectric properties of transition metal diselenides. Highlights: Black-Right-Pointing-Pointer Single phase bulk Ni and Ti co-intercalated TiSe{sub 2} samples prepared by spark plasma sintering. Black-Right-Pointing-Pointer Density and X-ray diffraction suggest that the Ni and excess Ti are ordered in the Van der Waals gap. Black-Right-Pointing-Pointer Co-intercalation of Ni and Ti can be used to control electron-hole ratio and structural disorder.

  10. Large Eddy Simulation of laser ignition and compressible reacting flow in a rocket-like

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    combustion devices. The technical needs for internal-combustion (IC) engines and aircraft combustors have in a rocket engine is a critical problem for combustion cham- ber design. Delayed ignition may lead to high without failure. The combustion initiation in rocket engines is usually based on pyrotechnic devices

  11. Toward LES of an ignition sequence in a full helicopter combustor

    E-Print Network [OSTI]

    Toward LES of an ignition sequence in a full helicopter combustor M. Boileau , J.B. Mossa , B in a cold and rarified atmosphere is a critical issue for many manu- facturers. In the Vesta combustor machine - where the use of 2048 parallel processors have enabled to start computing on the full combustor

  12. Kinetic Ignition Enhancement of Diffusion Flames by Nonequilibrium Magnetic Gliding Arc Plasma

    E-Print Network [OSTI]

    Ju, Yiguang

    -assisted ignition in supersonic flow, where a combination of thermal and nonthermal plasma would work more combustor. Therefore, the total heat release, thrust, and propulsive efficiency cannot fully be realized: thermally or kinetically. Thermal enhancement is accomplished by increasing the translational gas

  13. Shock-Tube Study of Methane Ignition with NO2 and N2O

    E-Print Network [OSTI]

    Pemelton, John

    2012-10-19T23:59:59.000Z

    . The experimental pressure range was 1 - 44 atm and the temperature range tested was 1177 – 2095 K. The additives NO2 and N2O were added in concentrations from 831 ppm to 3539 ppm. The results of the mixtures with NO2 have a reduction in ignition delay time across...

  14. Engineering Peer Review June 5-7, 2001 1 FUSION IGNITION

    E-Print Network [OSTI]

    Engineering Peer Review June 5-7, 2001 1 FUSION IGNITION RESEARCH EXPERIMENT (FIRE) Machine Configuration Tom Brown (PPPL) June 5 ­ 7 , 2001 #12;Engineering Peer Review June 5-7, 2001 2 FIRE Configuration approach. Summary. #12;Engineering Peer Review June 5-7, 2001 3 FIRE Configuration Features Double null

  15. Safety and environmental process for the design and construction of the National Ignition Facility

    SciTech Connect (OSTI)

    Brereton, S.J., LLNL

    1998-05-27T23:59:59.000Z

    The National Ignition Facility (NIF) is a U.S. Department of Energy (DOE) laser fusion experimental facility currently under construction at the Lawrence Livermore National Laboratory (LLNL). This paper describes the safety and environmental processes followed by NIF during the design and construction activities.

  16. "Basic Research Directions Workshop on User Science at the National Ignition Facility"

    E-Print Network [OSTI]

    ) · that will make a difference for science (The Impact) In Laboratory Astrophysics, Nuclear Physics, Materials" Workshop May 9-12, 2011 Panel Chairs: Laboratory Astrophysics: Paul Drake (Michigan) Nuclear Physics: Bill at the National Ignition Facility Unprecedented environment for science · Matter temperatures exceeding 108 K

  17. Reactivity Controlled Compression Ignition (RCCI) Combustion on a Multi-Cylinder Light-Duty Diesel Engine

    SciTech Connect (OSTI)

    Curran, Scott [ORNL; Hanson, Reed M [ORNL; Wagner, Robert M [ORNL

    2012-01-01T23:59:59.000Z

    Reactivity controlled compression ignition is a low-temperature combustion technique that has been shown, both in computational fluid dynamics modeling and single-cylinder experiments, to obtain diesel-like efficiency or better with ultra-low nitrogen oxide and soot emissions, while operating primarily on gasoline-like fuels. This paper investigates reactivity controlled compression ignition operation on a four-cylinder light-duty diesel engine with production-viable hardware using conventional gasoline and diesel fuel. Experimental results are presented over a wide speed and load range using a systematic approach for achieving successful steady-state reactivity controlled compression ignition combustion. The results demonstrated diesel-like efficiency or better over the operating range explored with low engine-out nitrogen oxide and soot emissions. A peak brake thermal efficiency of 39.0% was demonstrated for 2600 r/min and 6.9 bar brake mean effective pressure with nitrogen oxide emissions reduced by an order of magnitude compared to conventional diesel combustion operation. Reactivity controlled compression ignition emissions and efficiency results are compared to conventional diesel combustion operation on the same engine.

  18. Federal Managers Update on the National Ignition Campaign (NIC) February 14, 2012

    E-Print Network [OSTI]

    , Sean Finnegan (SC) and Sam Brinker (LSO) were briefed by the National Ignition Campaign (NIC) team properties (velocity and thickness) of the capsule ablator and of neutron and x-ray images of the compressed technique, registration of x-ray images, fusion neutron images, and down-scattered neutron images

  19. Detailed Analysis and Control Issues of Homogeneous Charge Compression Ignition (HCCI)

    SciTech Connect (OSTI)

    Aceves, Salvador M.; Flowers, Daniel L.; Martinez-Frias, Joel; Espinosa-Loza, Francisco; Dibble, Robert

    2002-08-25T23:59:59.000Z

    Homogeneous charge compression ignition (HCCI) is a new combustion technology that may develop as an alternative to diesel engines with high efficiency and low NOx and particulate matter emissions. This paper describes the HCCI research activities being currently pursued at Lawrence Livermore National Laboratory and at the University of California Berkeley. Current activities include analysis as well as experimental work.

  20. Steady-State Multiplicity and Stability of Thermal Equilibria in Homogeneous Charge Compression Ignition (HCCI) Engines

    E-Print Network [OSTI]

    Stefanopoulou, Anna

    Ignition (HCCI) Engines C. J. Chiang and A. G. Stefanopoulou University of Michigan, Ann Arbor Email the autoignition of HCCI engines is analyzed in this paper. We find conditions under which steady into account the internal feedback structure of the thermal autoignition dynamics. Specifically, HCCI

  1. Sensitivity Analysis of Combustion Timing and Duration of Homogeneous Charge Compression Ignition (HCCI) Engines

    E-Print Network [OSTI]

    Stefanopoulou, Anna

    (HCCI) Engines C. J. Chiang and A. G. Stefanopoulou University of Michigan, Ann Arbor Email: cjchiang of a Homogeneous Charge Com- pression Ignition (HCCI) engine. Qualitative and quantitative information on the individual effects of fuel and exhaust gas recirculation (EGR) on the HCCI combustion is provided. Using

  2. Ignition of a deuterium micro-detonation with a gigavolt super marx generator

    E-Print Network [OSTI]

    Winterberg, Friedwardt

    2008-01-01T23:59:59.000Z

    The Centurion-Halite experiment demonstrated the feasibility of igniting a deuterium-tritium micro-explosion with an energy of not more than a few megajoule, and the Mike test, the feasibility of a pure deuterium explosion with an energy of more than 10^6 megajoule. In both cases the ignition energy was supplied by a fission bomb explosive. While an energy of a few megajoule, to be released in the time required of less than 10^-9 sec, can be supplied by lasers and intense particle beams, this is not enough to ignite a pure deuterium explosion. Because the deuterium-tritium reaction depends on the availability of lithium, the non-fusion ignition of a pure deuterium fusion reaction would be highly desirable. It is shown that this goal can conceivably be reached with a "Super Marx Generator", where a large number of "ordinary" Marx generators charge (magnetically insulated) fast high voltage capacitors of a second stage Marx generator, called a "Super Marx Generator", ultimately reaching gigavolt potentials with...

  3. Fusion Energy Research at The National Ignition Facility: The Pursuit of the Ultimate Clean, Inexhaustible

    E-Print Network [OSTI]

    Fusion Energy Research at The National Ignition Facility: The Pursuit of the Ultimate Clean, Inexhaustible Energy Source" John D. Moody, Lawrence Livermore National Laboratory" " Presented to: MIT ­ PSFC IAP 2014" " January 15, 2014" This work performed under the auspices of the U.S. Department of Energy

  4. International Conference on Microwave and High Frequency Heating Nottingham, UK, September 2013 Underwater Microwave Ignition of

    E-Print Network [OSTI]

    Jerby, Eli

    -cost operation [4, 5]. Thermite reaction as a self-propagated, high-temperature synthesis (SHS) process, Localized microwave heating, underwater ignition, combustion. INTRODUCTION Self-propagated thermite reactions between metal-oxide and metals typically burn at high flame temperatures, and require high

  5. Ignition and explosion of nanopowders: something new under Olivier Dufaud1

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    ones concern nanopowders fires and explosions [1]. In fact, since 2002 [2], one could quote the recent of micron-sized powders do not enable to evaluate the fire and explosion risk probabilities and gravitiesIgnition and explosion of nanopowders: something new under the dust Olivier Dufaud1 , Alexis Vignes

  6. An experimental investigation of the ignition properties of hydrogen and carbon monoxide

    E-Print Network [OSTI]

    Wooldridge, Margaret S.

    for syngas turbine applications S.M. Walton *, X. He, B.T. Zigler, M.S. Wooldridge Department of Mechanical of simulated syngas mixtures of hydrogen (H2), carbon monoxide (CO), oxygen (O2), nitrogen (N2), and carbon. Keywords: Carbon monoxide; Hydrogen; Syngas; Ignition; Rapid compression facility 1. Introduction Syngas

  7. Modeling of NO sensitization of IC engines surrogate fuels auto-ignition and combustion

    E-Print Network [OSTI]

    Anderlohr, Jörg; Bounaceur, Roda; Battin-Leclerc, Frédérique

    2009-01-01T23:59:59.000Z

    This paper presents a new chemical kinetic model developed for the simulation of auto-ignition and combustion of engine surrogate fuel mixtures sensitized by the presence of NOx. The chemical mechanism is based on the PRF auto-ignition model (n-heptane/iso-octane) of Buda et al. [1] and the NO/n-butane/n-pentane model of Glaude et al. [2]. The later mechanism has been taken as a reference for the reactions of NOx with larger alcanes (n-heptane, iso-octane). A coherent two components engine fuel surrogate mechanism has been generated which accounts for the influence of NOx on auto-ignition. The mechanism has been validated for temperatures between 700 K and 1100 K and pressures between 1 and 10 atm covering the temperature and pressure ranges characteristic of engine post-oxidation thermodynamic conditions. Experiments used for validation include jet stirred reactor conditions for species evolution as a function of temperature, as well as diesel HCCI engine experiments for auto-ignition delay time measurements...

  8. Pathway from the National Ignition Facility to an operational LIFE power plant

    E-Print Network [OSTI]

    Pathway from the National Ignition Facility to an operational LIFE power plant Presentation to AAAS next step, after NIF, is construction of a full-scale power plant NIF-1111-23807.ppt 4 #12 · PG&E · Southern Company · Wisconsin Energy · SSEB Power Plant Vendors Laser

  9. Transition from cool flame to thermal flame in compression ignition process

    SciTech Connect (OSTI)

    Yamada, Hiroyuki; Suzaki, Kotaro; Goto, Yuichi [National Traffic Safety and Environment Laboratory, 7-42-27 Jindaiji-Higashimachi, Chofu, Tokyo 182-0012 (Japan); Tezaki, Atsumu [Department of Mechanical and Intellectual Systems Engineering, University of Toyama, Gofuku 3190, Toyama-shi, Toyama 930-8555 (Japan)

    2008-07-15T23:59:59.000Z

    The mechanism that initiates thermal flames in compression ignition has been studied. Experimentally, a homogeneous charge compression ignition (HCCI) engine was used with DME, n-heptane, and n-decane. Arrhenius plots of the heat release rate in the HCCI experiments showed that rates of heat release with DME, n-heptane, and n-decane exhibited a certain activation energy that is identical to that of the H{sub 2}O{sub 2} decomposition reaction. The same feature was observed in diesel engine operation using ordinary diesel fuel with advanced ignition timing to make ignition occur after the end of fuel injection. These experimental results were reproduced in nondimensional simulations using kinetic mechanisms for DME, n-heptane, and n-decane, the last being developed by extending the n-heptane mechanism. Methanol addition, which suppresses low-temperature oxidation (LTO) and delays the ignition timing, had no effect on the activation energy obtained from the Arrhenius plot of heat release rate. Nevertheless, methanol addition lowered the heat release rates during the prethermal flame process. This is because H{sub 2}O{sub 2} formation during cool flame was reduced by adding methanol. The mechanism during the transition process from cool flame to thermal flame can be explained quantitatively using thermal explosion theory, in which the rate-determining reaction is H{sub 2}O{sub 2} decomposition, assuming that heat release in this period is caused by partial oxidation of DME and HCHO initiated with the reaction with OH produced though H{sub 2}O{sub 2} decomposition. (author)

  10. Ignition of a deuterium micro-detonation with a gigavolt super marx generator

    E-Print Network [OSTI]

    Friedwardt Winterberg

    2008-12-01T23:59:59.000Z

    The Centurion-Halite experiment demonstrated the feasibility of igniting a deuterium-tritium micro-explosion with an energy of not more than a few megajoule, and the Mike test, the feasibility of a pure deuterium explosion with an energy of more than 10^6 megajoule. In both cases the ignition energy was supplied by a fission bomb explosive. While an energy of a few megajoule, to be released in the time required of less than 10^-9 sec, can be supplied by lasers and intense particle beams, this is not enough to ignite a pure deuterium explosion. Because the deuterium-tritium reaction depends on the availability of lithium, the non-fusion ignition of a pure deuterium fusion reaction would be highly desirable. It is shown that this goal can conceivably be reached with a "Super Marx Generator", where a large number of "ordinary" Marx generators charge (magnetically insulated) fast high voltage capacitors of a second stage Marx generator, called a "Super Marx Generator", ultimately reaching gigavolt potentials with an energy output of 100 megajoule. An intense 10^7 Ampere-GeV proton beam drawn from a "Super Marx Generator" can ignite a deuterium thermonuclear detonation wave in a compressed deuterium cylinder, where the strong magnetic field of the proton beam entraps the charged fusion reaction products inside the cylinder. In solving the stand-off problem, the stiffness of a GeV proton beam permits to place the deuterium target at a comparatively large distance from the wall of a cavity confining the deuterium micro-explosion.

  11. News -Little Geobacter still sparks discoveries after 20 years from the T... file:///C:/Documents%20and%20Settings/pbrown/My%20Documents/re... 1 of 2 6/19/2007 8:33 PM

    E-Print Network [OSTI]

    Lovley, Derek

    , Geobacter exhale electricity through 20 to 30 hair-like structures, just 3 to 5 nanometers in diameterNews - Little Geobacter still sparks discoveries after 20 years from the T... file:///C:/Documents%20and%20Settings/pbrown/My%20Documents/re... 1 of 2 6/19/2007 8:33 PM Little Geobacter still sparks

  12. Chemical Kinetic Reaction Mechanisms for Combustion of Hydrocarbon and Other Types of Chemical Fuels

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Reaction mechanisms have been tested and validated extensively through comparisons between computed results and measured data from laboratory experiments (e.g., shock tubes, laminar flames, rapid compression machines, flow reactors, stirred reactors) and from practical systems (e.g., diesel engines, spark-ignition engines, homogeneous charge, compression ignition (HCCI) engines). These kinetic models are used to examine a wide range of combustion systems.

  13. Kinetic modelling of a surrogate diesel fuel applied to 3D auto-ignition in HCCI engines

    E-Print Network [OSTI]

    Bounaceur, Roda; Fournet, René; Battin-Leclerc, Frédérique; Jay, S; Da Cruz, A Pires

    2007-01-01T23:59:59.000Z

    The prediction of auto-ignition delay times in HCCI engines has risen interest on detailed chemical models. This paper described a validated kinetic mechanism for the oxidation of a model Diesel fuel (n-decane and ?-methylnaphthalene). The 3D model for the description of low and high temperature auto-ignition in engines is presented. The behavior of the model fuel is compared with that of n-heptane. Simulations show that the 3D model coupled with the kinetic mechanism can reproduce experimental HCCI and Diesel engine results and that the correct modeling of auto-ignition in the cool flame region is essential in HCCI conditions.

  14. A Concept Exploration Program in Fast Ignition Inertial Fusion — Final Report

    SciTech Connect (OSTI)

    Stephens, Richarad Burnite [General Atomics] [General Atomics; Freeman, Richard R. [The Ohio State University] [The Ohio State University; Van Woekom, L. D. [The Ohio State University] [The Ohio State University; Key, M. [Lawrence Livermore National Laboratory] [Lawrence Livermore National Laboratory; MacKinnon, Andrew J. [Lawrence Livermore National Laboratory] [Lawrence Livermore National Laboratory; Wei, Mingsheng [General Atomics] [General Atomics

    2014-02-27T23:59:59.000Z

    The Fast Ignition (FI) approach to Inertial Confinement Fusion (ICF) holds particular promise for fusion energy because the independently generated compression and ignition pulses allow ignition with less compression, resulting in (potentially) higher gain. Exploiting this concept effectively requires an understanding of the transport of electrons in prototypical geometries and at relevant densities and temperatures. Our consortium, which included General Atomics (GA), The Ohio State University (OSU), the University of California, San Diego (UCSD), University of California, Davis (UC-Davis), and Princeton University under this grant (~$850K/yr) and Lawrence Livermore National Laboratory (LLNL) under a companion grant, won awards in 2000, renewed in 2005, to investigate the physics of electron injection and transport relevant to the FI concept, which is crucial to understand electron transport in integral FI targets. In the last two years we have also been preparing diagnostics and starting to extend the work to electron transport into hot targets. A complementary effort, the Advanced Concept Exploration (ACE) program for Fast Ignition, was funded starting in 2006 to integrate this understanding into ignition schemes specifically suitable for the initial fast ignition attempts on OMEGA and National Ignition Facility (NIF), and during that time these two programs have been managed as a coordinated effort. This result of our 7+ years of effort has been substantial. Utilizing collaborations to access the most capable laser facilities around the world, we have developed an understanding that was summarized in a Fusion Science & Technology 2006, Special Issue on Fast Ignition. The author lists in the 20 articles in that issue are dominated by our group (we are first authors in four of them). Our group has published, or submitted 67 articles, including 1 in Nature, 2 Nature Physics, 10 Physical Review Letters, 8 Review of Scientific Instruments, and has been invited to give numerous talks at national and international conferences (including APS-DPP, IAEA, FIW). The advent of PW capabilities – at Rutherford Appleton Lab (UK) and then at Titan (LLNL) (2005 and 2006, respectively), was a major step toward experiments in ultra-high intensity high-energy FI relevant regime. The next step comes with the activation of OMEGA EP at LLE, followed shortly by NIF-ARC at LLNL. These capabilities allow production of hot dense material for electron transport studies. In this transitional period, considerable effort has been spent in developing the necessary tools and experiments for electron transport in hot and dense plasmas. In addition, substantial new data on electron generation and transport in metallic targets has been produced and analyzed. Progress in FI detailed in §2 is related to the Concept Exploration Program (CEP) objectives; this section is a summary of the publications and presentations listed in §5. This work has benefited from the synergy with work on related Department of Energy (DOE) grants, the Fusion Science Center and the Fast Ignition Advanced Concept Exploration grant, and from our interactions with overseas colleagues, primarily at Rutherford Appleton Laboratory in the UK, and the Institute for Laser Engineering in Japan.

  15. A study of ignition and combustion characteristics of isolated coal water slurry droplet using digital image processing technique 

    E-Print Network [OSTI]

    Bhadra, Tanmoy

    1998-01-01T23:59:59.000Z

    diameter and ambient oxygen concentrations. Simplified phenomen ological type models are presented in order to determine the number of particles. interparticle spacing and density of coal water slurry droplet. Finally qualitative relations between ignition...

  16. Design of a viable homogeneous-charge compression-ignition (HCCI) engine : a computational study with detailed chemical kinetics

    E-Print Network [OSTI]

    Yelvington, Paul E., 1977-

    2005-01-01T23:59:59.000Z

    The homogeneous-charge compression-ignition (HCCI) engine is a novel engine technology with the potential to substantially lower emissions from automotive sources. HCCI engines use lean-premixed combustion to achieve good ...

  17. 2924 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 36, NO. 6, DECEMBER 2008 Kinetic Ignition Enhancement of H2 Versus

    E-Print Network [OSTI]

    Ju, Yiguang

    , any type of enhancement of ignition in high- speed flow is complicated by the coupling of heat and rad 12, 2008. This work was supported in part by the Air Force Office of Scientific Research under Grant

  18. Review of the National Ignition Campaign 2009-2012 John Lindl, Otto Landen, John Edwards, Ed Moses, and NIC Team

    E-Print Network [OSTI]

    ) as well as the development, fielding, qualification, and integration of the wide range of capabilities required to install and performance qualify the equipment and experimental platforms needed for ignition

  19. Performance of High-Convergence, Layered DT Implosions with Extended-Duration Pulses at the National Ignition Facility

    E-Print Network [OSTI]

    Gatu Johnson, Maria

    Radiation-driven, low-adiabat, cryogenic DT layered plastic capsule implosions were carried out on the National Ignition Facility (NIF) to study the sensitivity of performance to peak power and drive duration. An implosion ...

  20. "Defense-in-Depth" Laser Safety and the National Ignition Facility

    SciTech Connect (OSTI)

    King, J J

    2010-12-02T23:59:59.000Z

    The National Ignition Facility (NIF) is the largest and most energetic laser in the world contained in a complex the size of a football stadium. From the initial laser pulse, provided by telecommunication style infrared nanoJoule pulsed lasers, to the final 192 laser beams (1.8 Mega Joules total energy in the ultraviolet) converging on a target the size of a pencil eraser, laser safety is of paramount concern. In addition to this, there are numerous high-powered (Class 3B and 4) diagnostic lasers in use that can potentially send their laser radiation travelling throughout the facility. With individual beam paths of up to 1500 meters and a workforce of more than one thousand, the potential for exposure is significant. Simple laser safety practices utilized in typical laser labs just don't apply. To mitigate these hazards, NIF incorporates a multi layered approach to laser safety or 'Defense in Depth.' Most typical high-powered laser operations are contained and controlled within a single room using relatively simplistic controls to protect both the worker and the public. Laser workers are trained, use a standard operating procedure, and are required to wear Personal Protective Equipment (PPE) such as Laser Protective Eyewear (LPE) if the system is not fully enclosed. Non-workers are protected by means of posting the room with a warning sign and a flashing light. In the best of cases, a Safety Interlock System (SIS) will be employed which will 'safe' the laser in the case of unauthorized access. This type of laser operation is relatively easy to employ and manage. As the operation becomes more complex, higher levels of control are required to ensure personnel safety. Examples requiring enhanced controls are outdoor and multi-room laser operations. At the NIF there are 192 beam lines and numerous other Class 4 diagnostic lasers that can potentially deliver their hazardous energy to locations far from the laser source. This presents a serious and complex potential hazard to personnel. Because of this, a multilayered approach to safety is taken. This paper presents the philosophy and approach taken at the NIF in the multi-layered 'defense-in-depth' approach to laser safety.