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1

Laser Spark Distribution and Ignition System  

Laser Spark Distribution and Ignition System Opportunity The Department of Energy’s National Energy Technology Laboratory (NETL) is seeking licensing partners ...

2

Laser Spark Distribution and Ignition System  

NLE Websites -- All DOE Office Websites (Extended Search)

Spark Distribution and Ignition System Spark Distribution and Ignition System Opportunity The Department of Energy's National Energy Technology Laboratory (NETL) is seeking licensing partners interested in implement- ing United States Patent Number 7,421,166 entitled "Laser Spark Distribution and Ignition System." Disclosed in this patent is NETL's laser spark distribution and ignition system, which reduces the high-power optical requirements normally needed for such a system by using optical fibers to deliver low-peak-energy pumping pulses to a laser amplifier or laser oscillator. Laser spark generators then produce a high-peak-power 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 breakdown spectroscopy diagnostic sensors.

3

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

E-Print Network (OSTI)

Spark ignition of the air-fuel mixture at the appropriate time is important for successful flame initiation and complete combustion thereafter without unnecessary emissions. The physical and chemical reactions taking place between the spark plug electrodes during spark delivery determine the intensity of the spark and subsequent flame initiation. The energy of spark and the duration of its delivery are dependent on the ignition system design. The characteristics of the spark plug determine the interaction of the spark with the air-fuel mixture. The compression pressure, combustion chamber temperature and mixture motion at the time of spark generation play a significant role in the flame initiation process. All of these parameters are responsible for the resulting spark discharge and flame initiation process. The objectives of this research include investigation of the different phases of spark discharge and development of a thermodynamic analysis to determine the rate of change of the spark kernel temperature with time during the initial phases of the spark discharge. The effect of spark energy delivery rate, heat transfer losses and mass entrainment on the spark kernel temperature was determined through the thermodynamic analysis. This research also 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 pressure on the characteristics of the spark discharge. Images of spark discharge were captured through photography using three different types of electrode geometries and also by varying the pressure and by changing the ignition energy using different condensers in the ignition system. Finally, the results of the thermodynamic analysis were compared with the results from the experiment.

Khare, Yogesh Jayant

2000-01-01T23:59:59.000Z

4

Laser Spark Distribution and Ignition System  

Disclosed in this patent is NETL’s laser spark distribution and ignition system, which reduces the high-power optical requirements normally needed for such a system by using optical fibers to deliver low-peak-energy pumping pulses to a laser amplifier ...

5

Study on Adaptive Ignition Energy System of Two-Stroke Spark Ignition Engine  

Science Conference Proceedings (OSTI)

Kerosene is characteristic of higher flash point, poorer evaporation, higher energy density, higher use safety, higher ignition temperature, and slower combustion velocity than that of gasoline. Therefore, kerosene is widely used in the field of navigation. ... Keywords: CDI, Adaptive Ignition Energy, Spark Ignition Engine, Microcontroller Unit

Binglin Li; Minxiang Wei

2009-10-01T23:59:59.000Z

6

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

E-Print Network (OSTI)

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 ...

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

2005-01-01T23:59:59.000Z

7

Engines - Spark Ignition Engines  

NLE Websites -- All DOE Office Websites (Extended Search)

Spark Ignition Engines Spark Ignition Engines Thomas Wallner and omni engine Thomas Wallner and the omnivorous engine Background Today the United States import more than 60% of its crude oil and petroleum products. Transportation accounts for a major portion of these imports. Research in this field is focused on reducing the dependency on foreign oil by increasing the engine efficiency on the one hand and blending gasoline with renewable domestic fuels, such as ethanol, on the other. Argonne's Research The main focus of research is on evaluation of advanced combustion concepts and effects of fuel properties on engine efficiency, performance and emissions. The platforms used are a single-cylinder research engine as well as an automotive-size four-cylinder engine with direct fuel injection.

8

History and future of spark ignition engines  

SciTech Connect

A report on the history and future of spark ignition engines for automobile propulsion is presented, with particular emphasis on their environmental impact. Topics covered include: factors affecting early decisions in favor of spark ignition engines and influencing continued reliance on spark ignition engines; the early history of automobile engines, including propulsion by steam, electricity, spark ignition, and diesel power; and contemporary alternative power sources such as the stratified charge engine and the Wankel rotary combustion engine. There appear to be no equivalents in knowledge, experience, or data with alternative engine designs to allow for the prediction that a change from spark ignition propulsion to one of the possible alternatives would be beneficial either in terms of emission reduction or performance and fuel economy. The stratified charge engine, however, appears to offer great promise for adequate emission control with good fuel economy and performance characteristics; moreover, it has the significant advantage of being an incremental change from the current spark ignition engine.

1973-01-01T23:59:59.000Z

9

Spark Ignited Turbulent Flame Kernel Growth  

DOE Green Energy (OSTI)

An experimental study of the effects of spark power and of incomplete fuel-air mixing on spark-ignited flame kernel growth was conducted in turbulent propane-air mixtures at 1 atm, 300K conditions. The results showed that increased spark power resulted in an increased growth rate, where the effect of short duration breakdown sparks was found to persist for times of the order of milliseconds. The effectiveness of increased spark power was found to be less at high turbulence and high dilution conditions. Increased spark power had a greater effect on the 0-5 mm burn time than on the 5-13 mm burn time, in part because of the effect of breakdown energy on the initial size of the flame kernel. And finally, when spark power was increased by shortening the spark duration while keeping the effective energy the same there was a significant increase in the misfire rate, however when the spark power was further increased by increasing the breakdown energy the misfire rate dropped to zero. The results also showed that fluctuations in local mixture strength due to incomplete fuel-air mixing cause the flame kernel surface to become wrinkled and distorted; and that the amount of wrinkling increases as the degree of incomplete fuel-air mixing increases. Incomplete fuel-air mixing was also found to result in a significant increase in cyclic variations in the flame kernel growth. The average flame kernel growth rates for the premixed and the incompletely mixed cases were found to be within the experimental uncertainty except for the 33%-RMS-fluctuation case where the growth rate was significantly lower. The premixed and 6%-RMS-fluctuation cases had a 0% misfire rate. The misfire rates were 1% and 2% for the 13%-RMS-fluctuation and 24%-RMS-fluctuation cases, respectively; however, it drastically increased to 23% in the 33%-RMS-fluctuation case.

Santavicca, D.A.

1995-06-01T23:59:59.000Z

10

Laser-induced spark ignition fundamental and applications  

SciTech Connect

Laser ignition has become an active research topic in recent years because it has the potential to replace the conventional electric spark plugs in engines that are required to operate under much higher compression ratios, faster compression rates, and much leaner fuel-to-air ratios than gas engines today. It is anticipated that the igniter in these engines will face with pressures as high as 50MPa and temperatures as high as 4000 K. Using the conventional ignition system, the required voltage and energy must be greatly increased (voltages in excess of 40 kV) to reliably ignite the air and fuel mixture under these conditions. Increasing the voltage and energy does not always improve ignitability but it does create greater reliability problem. The objective of this paper is to review past work to identify some fundamental issues underlying the physics of the laser spark ignition process and research needs in order to bring the laser ignition concept into the realm of reality.

Tran, P.X.

2006-05-01T23:59:59.000Z

11

Fundamental Studies of Ignition Process in Large Natural Gas Engines Using Laser Spark Ignition  

Science Conference Proceedings (OSTI)

Past research has shown that laser ignition provides a potential means to reduce emissions and improve engine efficiency of gas-fired engines to meet longer-term DOE ARES (Advanced Reciprocating Engine Systems) targets. Despite the potential advantages of laser ignition, the technology is not seeing practical or commercial use. A major impediment in this regard has been the 'open-path' beam delivery used in much of the past research. This mode of delivery is not considered industrially practical owing to safety factors, as well as susceptibility to vibrations, thermal effects etc. The overall goal of our project has been to develop technologies and approaches for practical laser ignition systems. To this end, we are pursuing fiber optically coupled laser ignition system and multiplexing methods for multiple cylinder engine operation. This report summarizes our progress in this regard. A partial summary of our progress includes: development of a figure of merit to guide fiber selection, identification of hollow-core fibers as a potential means of fiber delivery, demonstration of bench-top sparking through hollow-core fibers, single-cylinder engine operation with fiber delivered laser ignition, demonstration of bench-top multiplexing, dual-cylinder engine operation via multiplexed fiber delivered laser ignition, and sparking with fiber lasers. To the best of our knowledge, each of these accomplishments was a first.

Azer Yalin; Bryan Willson

2008-06-30T23:59:59.000Z

12

NETL: NETL - Media Backgrounder: Laser spark ignition for lean...  

NLE Websites -- All DOE Office Websites (Extended Search)

ratios and three timing conditions were compared. The NETL research provides the first lean-burn natural gas engine data using a laser-spark ignition source and the first...

13

Engines - Spark Ignition Engines - Direct Injection - Omnivorous Engine  

NLE Websites -- All DOE Office Websites (Extended Search)

Direct Injection, Spark-Ignited Engines Direct Injection, Spark-Ignited Engines Omnivorous Engine Omnivorous Engine Setup Omnivorous Engine Setup New engine technology has made possible engines that will operate on a wide variety of fuel inputs, from gasoline to naptha to ethanol to methanol, without driver intervention. Although flexible fuel vehicles have been produced in the millions, their engines have always been optimized for gasoline operation while accepting significant performance and efficiency degradations when using the alternative fuel. This project seeks to combine in-cylinder measurement technology, and advanced controls to optimize spark timing, the quantity and timing of injected fuel, to produce an "omnivorous engine"--one that will be able to run on any liquid spark ignition fuel with optimal efficiency and low

14

Spark ignited turbulent flame kernel growth. Annual report, January--December 1991  

DOE Green Energy (OSTI)

An experimental study of the effect of spark power on the growth rate of spark-ignited flame kernels was conducted in a turbulent flow system at 1 atm, 300 K conditions. All measurements were made with premixed, propane-air at a fuel/air equivalence ratio of 0.93, with 0%, 8% or 14% dilution. Two flow conditions were studied: a low turbulence intensity case with a mean velocity of 1.25 m/sec and a turbulence intensity of 0.33 m/sec, and a high turbulence intensity case with a mean velocity of 1.04 m/sec and a turbulence intensity of 0.88 m/sec. The growth of the spark-ignited flame kernel was recorded over a time interval from 83 {mu}sec to 20 msec following the start of ignition using high speed laser shadowgraphy. In order to evaluate the effect of ignition spark power, tests were conducted with a long duration (ca 4 msec) inductive discharge ignition system with an average spark power of ca 14 watts and two short duration (ca 100 nsec) breakdown ignition systems with average spark powers of ca 6 {times} 10{sup 4} and ca 6 {times} 10{sup 5} watts. The results showed that increased spark power resulted in an increased growth rate, where the effect of short duration breakdown sparks was found to persist for times of the order of milliseconds. The effectiveness of increased spark power was found to be less at high turbulence and high dilution conditions. Increased spark power had a greater effect on the 0--5 mm burn time than on the 5--13 mm burn time, in part because of the effect of breakdown energy on the initial size of the flame kernel. And finally, when spark power was increased by shortening the spark duration while keeping the effective energy the same there was a significant increase in the misfire rate, however when the spark power was further increased by increasing the breakdown energy the misfire rate dropped to zero.

Santavicca, D.A.

1994-06-01T23:59:59.000Z

15

FY2001 Progress Report for the Spark Ignition Direct Injection R&D Program  

NLE Websites -- All DOE Office Websites (Extended Search)

SPARK IGNITION, SPARK IGNITION, DIRECT INJECTION ENGINE R&D 2 0 0 1 A N N U A L P R O G R E S S R E P O R T U.S. Department of Energy Energy Efficiency and Renewable Energy Office of Transportation Technologies A C K N O W L E D G E M E N T We would like to express our sincere appreciation to Argonne National Laboratory and Computer Systems Management, Inc., for their artistic and technical contributions in preparing and publishing this report. In addition, we would like to thank all our program participants for their contributions to the programs and all the authors who prepared the project abstracts that comprise this report. U.S. Department of Energy Office of Transportation Technologies 1000 Independence Avenue, S.W. Washington, DC 20585-0121 FY 2001 Progress Report for the Spark Ignition Direct Injection R&D Program

16

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

E-Print Network (OSTI)

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.

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

2003-12-28T23:59:59.000Z

17

PLIF flow visualization of methane gas jet from spark plug fuel injector in a direct injection spark ignition engine  

Science Conference Proceedings (OSTI)

A Spark Plug Fuel Injection (SPFI), which is a combination of a fuel injector and a spark plug was developed with the aim to convert any gasoline port injection spark ignition engine to gaseous fuel direct injection [1]. A direct fuel injector is combined ... Keywords: air-fuel mixing, direct fuel injection, flow visualization, gaseous fuel, laser-induced fluorescent

Taib Iskandar Mohamad; How Heoy Geok

2008-11-01T23:59:59.000Z

18

Burner ignition system  

SciTech Connect

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.

Carignan, Forest J. (Bedford, MA)

1986-01-21T23:59:59.000Z

19

Parametric combustion modeling for ethanol-gasoline fuelled spark ignition engines.  

E-Print Network (OSTI)

?? Ethanol-gasoline fuel blends are increasingly being used in spark ignition (SI) engines due to continued growth in renewable fuels as part of a growing… (more)

Yeliana

2011-01-01T23:59:59.000Z

20

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

E-Print Network (OSTI)

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 ...

Cedrone, Kevin David

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ignition system spark" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

A comparison between direct spark ignition and prechamber ignition in an internal combustion engine  

DOE Green Energy (OSTI)

We simulated the flow field and flame propagation near top dead center in a generic large-bore internal combustion engine using the COYOTE computer program, which is based on the full Navier-Stokes equations for a fluid mixture. The combustion chamber is a right circular cylinder, and the main charge is uniformly premixed. The calculations are axisymmetric. The results illustrate the differences in flow patterns, flame propagation, and thermal NO production between ignition with a spark plug and with a small prechamber. In the spark-ignited case, the flame propagates away from the spark plug approximately as a segment of a spherical surface, just as expected. With the prechamber, a high speed jet of hot combustion products shoots into the main chamber, quickly producing a large flame sheet that spreads along the piston face. The prechamber run consumes all of the fuel in half the time required by the spark-ignited case. The two cases produce comparable amounts of thermal NO at the end of fuel combustion.

Cloutman, L.D.

1993-12-03T23:59:59.000Z

22

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

E-Print Network (OSTI)

1 THE CONCEPT OF ISOCHORIC CENTRAL SPARK IGNITION AND ITS FUEL GAIN IN INERTIAL FUSION of the best methods in inertial confinement fusion (ICF) is the concept of central spark ignition, consisting of two distinct regions named as hot and cold regions and formed by hydro-dynamical implosion of fuel

Paris-Sud XI, Université de

23

Spark ignited turbulent flame kernel growth. Annual report, January--December, 1992  

DOE Green Energy (OSTI)

Cyclic combustion variations in spark-ignition engines limit the use of dilute charge strategies for achieving low NO{sub x} emissions and improved fuel economy. Results from an experimental study of the effect of incomplete fuel-air mixing (ifam) on spark-ignited flame kernel growth in turbulent propane-air mixtures are presented. The experiments were conducted in a turbulent flow system that allows for independent variation of flow parameters, ignition system parameters, and the degree of fuel-air mixing. Measurements were made at 1 atm and 300 K conditions. Five cases were studied; a premixed and four incompletely mixed cases with 6%, 13%, 24% and 33% RMS (root-mean-square) fluctuations in the fuel/air equivalence ratio. High speed laser shadowgraphy at 4,000 frames-per-second was used to record flame kernel growth following spark ignition, from which the equivalent flame kernel radius as a function of time was determined. The effect of ifam was evaluated in terms of the flame kernel growth rate, cyclic variations in the flame kernel growth, and the rate of misfire. The results show that fluctuations in local mixture strength due to ifam cause the flame kernel surface to become wrinkled and distorted; and that the amount of wrinkling increases as the degree of ifam. Ifam was also found to result in a significant increase in cyclic variations in the flame kernel growth. The average flame kernel growth rates for the premixed and the incompletely mixed cases were found to be within the experimental uncertainty except for the 33%-RMS-fluctuation case where the growth rate is significantly lower. The premixed and 6%-RMS-fluctuation cases had a 0% misfire rate. The misfire rates were 1% and 2% for the 13%-RMS-fluctuation and 24%-RMS-fluctuation cases, respectively; however, it drastically increased to 23% in the 33%-RMS-fluctuation case.

Santavicca, D.A.

1994-06-01T23:59:59.000Z

24

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

E-Print Network (OSTI)

spark ignition . Particle velocity at a flame front Profileof apparent flame front approaching a position at a side warolled-up votex and CH4-air flame; equivalence ratio 0.6,

Ishikawa, Nobuhiko

2011-01-01T23:59:59.000Z

25

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

E-Print Network (OSTI)

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, ...

Radovanovic, Michael S

2006-01-01T23:59:59.000Z

26

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

DOE Green Energy (OSTI)

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.

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

2011-01-01T23:59:59.000Z

27

Application of neural network for air-fuel ratio identification in spark ignition engine  

Science Conference Proceedings (OSTI)

In the present work, Recurrent Neural Network (RNN) is used for Air-Fuel Ratio (AFR) identification in Spark Ignition (SI) engine. AFR identification is difficult due to nonlinear and dynamic behaviour of SI engines. Delays present in the engine ... Keywords: AFR sensors, RNNs, air-fuel ratio control, air-fuel ratio sensors, engine modelling, recurrent neural networks, simulation, spark ignition engines, virtual sensors

Samir Saraswati; Satish Chand

2008-10-01T23:59:59.000Z

28

Conversion of a diesel engine to a spark ignition natural gas engine  

DOE Green Energy (OSTI)

Requirements for alternatives to diesel-fueled vehicles are developing, particularly in urban centers not in compliance with mandated air quality standards. An operator of fleets of diesel- powered vehicles may be forced to either purchase new vehicles or equip some of the existing fleets with engines designed or modified to run on alternative fuels. In converting existing vehicles, the operator can either replace the existing engine or modify it to burn an alternative fuel. Work described in this report addresses the problem of modifying an existing diesel engine to operate on natural gas. Tecogen has developed a technique for converting turbocharged automotive diesel engines to operate as dedicated spark-ignition engines with natural gas fuel. The engine cycle is converted to a more-complete-expansion cycle in which the expansion ratio of the original engine is unchanged while the effective compression ratio is lowered, so that engine detonation is avoided. The converted natural gas engine, with an expansion ratio higher than in conventional spark- ignition natural gas engines, offers thermal efficiency at wide-open- throttle conditions comparable to its diesel counterpart. This allows field conversion of existing engines. Low exhaust emissions can be achieved when the engine is operated with precise control of the fuel air mixture at stoichiometry with a 3-way catalyst. A Navistar DTA- 466 diesel engine with an expansion ratio of 16.5 to 1 was converted in this way, modifying the cam profiles, increasing the turbocharger boost pressure, incorporating an aftercooler if not already present, and adding a spark-ignition system, natural gas fuel management system, throttle body for load control, and an electronic engine control system. The proof-of-concept engine achieved a power level comparable to that of the diesel engine without detonation. A conversion system was developed for the Navistar DT 466 engine. NOx emissions of 1.5 g/bhp-h have been obtained.

NONE

1996-09-01T23:59:59.000Z

29

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

E-Print Network (OSTI)

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, current, power, energy and duration), electrode design, electrode gap and compression ratio were the control variables and A/F lean limit, fuel consumption and hydrocarbon and oxides of nitrogen emission concentrations were the response variables. Experiments were performed on a General Motors' 2.2 liter four cylinder engine. Spark electrical characteristics were varied by applying various primary voltages and secondary resistances to the production inductive ignition system, with the engine operating at two operating conditions, a light load and a road load, and with two compression ratios. Cylinder pressure data was acquired to quantify load and combustion stability. Spark electrical characteristics were acquired with a digital oscilloscope to quantify secondary spark electrical characteristics. The results indicated that the response variables were generally insensitive to all the control variables, except for compression ratio. However, contrary to the literature, the A/F lean limit and fuel efficiency degraded with a higher compression ratio. Single and multi-variant linear regressions were studied between the A/F lean limit and the spark electrical characteristics. The only statistically significant and notable finding was a multi-variant linear regression of the A/F lean limit to increasing spark duration and decreasing spark energy at the road load operating condition. Statistical significance of the effect of the ignition system control variables on the response variables was higher at the road load than the light load operating condition. Emissions responded as expected with the higher compression ratio.

Chlubiski, Vincent Daniel

1997-01-01T23:59:59.000Z

30

Thermal ignition combustion system  

DOE Patents (OSTI)

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.

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

1988-04-19T23:59:59.000Z

31

Enhanced model and fuzzy strategy of air to fuel ratio control for spark ignition engines  

Science Conference Proceedings (OSTI)

Various mathematical models for the air to fuel ratio and control for spark ignition (SI) engines have been proposed to satisfy technical specifications. This paper reveals an improvement of the mean value model (MVEM) and a simple yet effective nonlinear ... Keywords: Air-fuel ratio, FOPDDT, Fuzzy control, Internal combustion, Nonlinear control

Anurak Jansri; Pitikhate Sooraksa

2012-09-01T23:59:59.000Z

32

Fiber laser coupled optical spark delivery system  

DOE Patents (OSTI)

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.

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

33

Devices to improve the performance of a conventional two-stroke spark ignition engine  

DOE Green Energy (OSTI)

This paper presents research efforts made in three different phases with the objective of improving the fuel economy of and reducing exhaust emissions from conventional, carbureted, two-stroke spark ignition (SI) engines, which are widely employed in two-wheel transportation in India. A review concerning the existing two-stroke engine technology for this application is included. In the first phase, a new scavenging system was developed and tested to reduce the loss of fresh charge through the exhaust port. In die second phase, the following measures were carried out to improve the combustion process: (1) using an in-cylinder catalyst, such as copper, chromium, and nickel, in the form of coating; (2) providing moderate thermal insulation in the combustion chamber, either by depositing thin ceramic material or by metal inserts; (3) developing a high-energy ignition system; and (4) employing high-octane fuel, such as methanol, ethanol, eucalyptus oil, and orange oil, as a blending agent with gasoline. Based on the effectiveness of the above measures, an optimized design was developed in the final phase to achieve improved performance. Test results indicate that with an optimized two-stroke SI engine, the maximum percentage improvement in brake thermal efficiency is about 31%, together with a reduction of 3400 ppm in hydrocarbons (HC) and 3% by volume of carbon monoxide (CO) emissions over the normal engine (at 3 kW, 3000 rpm). Higher cylinder peak pressures (3-5 bar), lower ignition delay (2-4{degrees}CA){degrees} and shorter combustion duration (4-10 {degrees}CA) are obtained. The knock-limited power output is also enhanced by 12.7% at a high compression ratio (CR) of 9:1. The proposed modifications in the optimized design are simple, low-cost and easy to adopt for both production and existing engines.

Poola, R.B. [Argonne National Lab., IL (United States); Nagalingam, B.; Gopalakrishnan, K.V. [Indian Inst. of Tech., Madras (India)

1995-06-01T23:59:59.000Z

34

Fiber coupled optical spark delivery system  

DOE Patents (OSTI)

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.

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

2008-08-12T23:59:59.000Z

35

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

E-Print Network (OSTI)

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 ...

Kar, Kenneth

36

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

E-Print Network (OSTI)

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 ...

Lang, Kevin R., 1980-

2006-01-01T23:59:59.000Z

37

Ignition assist systems for direct-injected, diesel cycle, medium-duty alternative fuel engines: Final report phase 1  

DOE Green Energy (OSTI)

This report is a summary of the results of Phase 1 of this contract. The objective was to evaluate the potential of assist technologies for direct-injected alternative fuel engines vs. glow plug ignition assist. The goal was to demonstrate the feasibility of an ignition system life of 10,000 hours and a system cost of less than 50% of the glow plug system, while meeting or exceeding the engine thermal efficiency obtained with the glow plug system. There were three tasks in Phase 1. Under Task 1, a comprehensive review of feasible ignition options for DING engines was completed. The most promising options are: (1) AC and the ''SmartFire'' spark, which are both long-duration, low-power (LDLP) spark systems; (2) the short-duration, high-power (SDHP) spark system; (3) the micropilot injection ignition; and (4) the stratified charge plasma ignition. Efforts concentrated on investigating the AC spark, SmartFire spark, and short-duration/high-power spark systems. Using proprietary pricing information, the authors predicted that the commercial costs for the AC spark, the short-duration/high-power spark and SmartFire spark systems will be comparable (if not less) to the glow plug system. Task 2 involved designing and performing bench tests to determine the criteria for the ignition system and the prototype spark plug for Task 3. The two most important design criteria are the high voltage output requirement of the ignition system and the minimum electrical insulation requirement for the spark plug. Under Task 3, all the necessary hardware for the one-cylinder engine test was designed. The hardware includes modified 3126 cylinder heads, specially designed prototype spark plugs, ignition system electronics, and parts for the system installation. Two 3126 cylinder heads and the SmartFire ignition system were procured, and testing will begin in Phase 2 of this subcontract.

Chan, A.K.

2000-02-23T23:59:59.000Z

38

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

E-Print Network (OSTI)

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.

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

2006-11-29T23:59:59.000Z

39

Railplug Ignition System for Enhanced Engine Performance and Reduced Maintenance  

SciTech Connect

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.

DK Ezekoye; Matt Hall; Ron Matthews

2005-08-01T23:59:59.000Z

40

Particulate Characteristics for Varying Engine Operation in a Gasoline Spark Ignited, Direct Injection Engine  

SciTech Connect

The objective of this research is a detailed investigation of particulate sizing and number count from a direct-injection spark-ignited (DISI) engine at different operating conditions. The engine is a 549 [cc] single-cylinder, four valve engine with a flat-top piston, fueled by Tier II EEE. A baseline engine operating condition, with a low number of particulates, was established and repeatability at this condition was ascertained. This baseline condition is specified as 2000 rpm, 320 kPa IMEP, 280 [°bTDC] end of injection (EOI), and 25 [°bTDC] ignition timing. The particle size distributions were recorded for particle sizes between 7 and 289 [nm]. The baseline particle size distribution was relatively flat, around 1E6 [dN/dlogDp], for particle diameters between 7 and 100 [nm], before dropping off to decreasing numbers at larger diameters. Distributions resulting from a matrix of different engine conditions were recorded. These varied parameters include load, air-to-fuel ratio (A/F), spark timing, injection timing, fuel rail pressure, and oil and coolant temperatures. Most conditions resulted with uni-modal type distributions usually with an increase in magnitude of particles in comparison to the baseline, with the exception of lean operation with retarded ignition timing. Further investigation revealed high sensitivity of the particle number and size distribution to changes in the engine control parameters. There was also a high sensitivity of the particle size distributions to small variations in A/F, ignition timing, and EOI. Investigations revealed the possibility of emissions oxidation in the exhaust and engine combustion instability at later EOI timings which therefore ruled out late EOI as the benchmark condition. Attempts to develop this benchmark revealed engine sensitivity to A/F and ignition timing, especially at later EOI operation

Farron, Carrie; Matthias, Nick; Foster, David E.; Andrie, Mike; Krieger, Roger; Najt, Paul; Narayanaswamy, Kushal; Solomon, Arun; Zelenyuk, Alla

2011-04-12T23:59:59.000Z

Note: This page contains sample records for the topic "ignition system spark" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Critical radius for sustained propagation of spark-ignited spherical flames  

Science Conference Proceedings (OSTI)

An experimental study was performed to determine the requirements for sustained propagation of spark-ignited hydrogen-air and butane-air flames at atmospheric and elevated pressures. Results show that sustained propagation is always possible for mixtures whose Lewis number is less than unity, as long as a flame can be initially established. However, for mixtures whose Lewis number is greater than unity, sustained propagation depends on whether the initially ignited flame can attain a minimum radius. This minimum radius was determined for mixtures of different equivalence ratios and pressures, and was found to agree moderately well with the theoretically predicted critical radius beyond which there is no solution for the adiabatic, quasi-steady propagation of the spherical flame. The essential roles of pressure, detailed chemistry, and the need to use local values in the quantitative evaluation of the flame response parameters are emphasized. (author)

Kelley, Andrew P.; Jomaas, Grunde; Law, Chung K. [Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08544 (United States)

2009-05-15T23:59:59.000Z

42

Some Notes on Sparks and Ignition of Fuels  

Science Conference Proceedings (OSTI)

This report compliments a concurrent analysis of the electromagnetic field threat to the fuel system of a transport aircraft. The accompanying effort assessed currents, voltages and power levels that may be induced upon fuel tank wiring from radio transmitters ...

Fisher Franklin A.

2000-03-01T23:59:59.000Z

43

The role of neuro-fuzzy modelling as a greening technique, in improving the performance of vehicular spark ignition engine  

Science Conference Proceedings (OSTI)

The spark ignition engine, by far, is the largest source of motive power in the world. Therefore, continuous endeavours to improve its performance are needed to save in fuel consumption and reduce cost. The main goal of this paper is to develop a neuro-fuzzy ...

Mashhour M. Bani Amer; Yousef S. H. Najjar

2010-02-01T23:59:59.000Z

44

A simple model for cyclic variations in a spark-ignition engine  

DOE Green Energy (OSTI)

We propose a simple, physically oriented model that explains important characteristics of cyclic combustion variations in spark-ignited engines. A key model feature is the interaction between stochastic, small-scale fluctuations in engine parameters and nonlinear deterministic coupling between successive engine cycles. Prior-cycle effects are produced by residual cylinder gas which alters volume-average in-cylinder equivalence ratio and subsequent combustion efficiency. The model`s simplicity allows rapid simulation of thousands of engine cycles, permitting in-depth statistical studies of cyclic variation patterns. Additional mechanisms for stochastic and prior-cycle effects can be added to evaluate their impact on overall engine performance. We find good agreement with our experimental data.

Daw, C.S.; Green, J.B. Jr.; Kennel, M.B.; Thomas, J.F. [and others

1996-11-01T23:59:59.000Z

45

Ethanol Blend Effects On Direct Injection Spark-Ignition Gasoline Vehicle Particulate Matter Emissions  

Science Conference Proceedings (OSTI)

Direct injection spark-ignition (DISI) gasoline engines can offer better fuel economy and higher performance over their port fuel-injected counterparts, and are now appearing increasingly in more U.S. vehicles. Small displacement, turbocharged DISI engines are likely to be used in lieu of large displacement engines, particularly in light-duty trucks and sport utility vehicles, to meet fuel economy standards for 2016. In addition to changes in gasoline engine technology, fuel composition may increase in ethanol content beyond the 10% allowed by current law due to the Renewable Fuels Standard passed as part of the 2007 Energy Independence and Security Act (EISA). In this study, we present the results of an emissions analysis of a U.S.-legal stoichiometric, turbocharged DISI vehicle, operating on ethanol blends, with an emphasis on detailed particulate matter (PM) characterization. Gaseous species, particle mass, and particle number concentration emissions were measured for the Federal Test Procedure urban driving cycle (FTP 75) and the more aggressive US06 cycle. Particle number-size distributions and organic to elemental carbon ratios (OC/EC) were measured for 30 MPH and 80 MPH steady-state operation. In addition, particle number concentration was measured during wide open throttle accelerations (WOTs) and gradual accelerations representative of the FTP 75. For the gaseous species and particle mass measurements, dilution was carried out using a full flow constant volume sampling system (CVS). For the particle number concentration and size distribution measurements, a micro-tunnel dilution system was employed. The vehicles were fueled by a standard test gasoline and 10% (E10) and 20% (E20) ethanol blends from the same supplier. The particle mass emissions were approximately 3 and 7 mg/mile for the FTP75 and US06, respectively, with lower emissions for the ethanol blends. During steady-state operation, the geometric mean diameter of the particle-number size distribution remained approximately the same (50 nm) but the particle number concentration decreased with increasing ethanol content in the fuel. In addition, increasing ethanol content significantly reduced the number concentration of 50 and 100 nm particles during gradual and WOT accelerations.

Storey, John Morse [ORNL; Lewis Sr, Samuel Arthur [ORNL; Barone, Teresa L [ORNL

2010-01-01T23:59:59.000Z

46

Electrically Distributed Optically Pumped Laser Spark Plug and...  

NLE Websites -- All DOE Office Websites (Extended Search)

Distributed Optically Pumped Laser Spark Plug and Ignition System Opportunity Research is active on the patent-pending technology, titled "Electrically Distributed Optically Pumped...

47

Optical diagnostics integrated with laser spark delivery system  

DOE Patents (OSTI)

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.

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

48

An investigation of lean combustion in a natural gas-fueled spark-ignited engine  

SciTech Connect

The objective of this work was to investigate the performance and emission characteristics of natural gas in an original equipment manufacturer (OEM), light-duty, spark-ignited engine being operated in the lean fueling regime and compare the operation with gasoline fueling cases. Data were acquired for several operating conditions of speed, throttle position, air-fuel equivalence ratio, and spark timing for both fuels. Results showed that for stoichiometric fueling, with a naturally aspirated engine, a power loss of 10 to 15 percent can be expected for natural gas over gasoline fueling. For lean operation, however, power increases can be expected for equivalence ratios below about {phi} = 0.80 with natural gas fueling as compared to gasoline. Higher brake thermal efficiencies can also be expected with natural gas fueling with maximum brake torque (MBT) timings over the range of equivalence ratios investigated in this work. Coefficient of variation (COV) data based on the indicated mean effective pressure (IMEP) demonstrated that the engine is much less sensitive to equivalence ratio leaning for natural gas fueling as compared to gasoline cases. The lean limit for a COV of 10 percent was about {phi} = 0.72 for gasoline and {phi} = 0.63 for natural gas. Lean fueling resulted in significantly reduced NO{sub x} levels where a lower plateau for NO{sub x} concentrations was reached at {phi} near or below 0.70, which corresponded to about 220 ppm. For natural gas fueling, this corresponded to about 1.21 gm/kW-h. Finally, with MBT timings, relatively short heat release durations were obtained for lean fueling with natural gas compared to gasoline.

Gupta, M.; Bell, S.R.; Tillman, S.T. [Univ. of Alabama, Tuscaloosa, AL (United States). Dept. of Mechanical Engineering

1996-06-01T23:59:59.000Z

49

Improving the performance and fuel consumption of dual chamber stratified charge spark ignition engines  

DOE Green Energy (OSTI)

A combined experimental and theoretical investigation of the nature of the combustion processes in a dual chamber stratified charge spark ignition engine is described. This work concentrated on understanding the mixing process in the main chamber gases. A specially constructed single cylinder engine was used to both conduct experiments to study mixing effects and to obtain experimental data for the validation of the computer model which was constructed in the theoretical portion of the study. The test procedures are described. Studies were conducted on the effect of fuel injection timing on performance and emissions using the combination of orifice size and prechamber to main chamber flow rate ratio which gave the best overall compromise between emissions and performance. In general, fuel injection gave slightly higher oxides of nitrogen, but considerably lower hydrocarbon and carbon monoxide emissions than the carbureted form of the engine. Experiments with engine intake port redesign to promote swirl mixing indicated a substantial increase in the power output from the engine and, that an equivalent power levels, the nitric oxide emissions are approximately 30% lower with swirl in the main chamber than without swirl. The development of a computer simulation of the combustion process showed that a one-dimensional combustion model can be used to accurately predict trends in engine operation conditions and nitric oxide emissions even though the actual flame in the engine is not completely one-dimensional, and that a simple model for mixing of the main chamber and prechamber intake gases at the start of compression proved adequate to explain the effects of swirl, ignition timing, overall fuel air ratio, volumetric efficiency, and variations in prechamber air fuel ratio and fuel rate percentage on engine power and nitric oxide emissions. (LCL)

Sorenson, S.C.; Pan, S.S.; Bruckbauer, J.J.; Gehrke, G.R.

1979-09-01T23:59:59.000Z

50

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

DOE Green Energy (OSTI)

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.

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

51

Laser Spark Plug Development  

Science Conference Proceedings (OSTI)

To meet the ignition system needs of large bore high pressure lean burn natural gas engines a laser diode side pumped passively Q-switched laser igniter was designed and tested. The laser was designed to produce the optical intensities needed to initiate ignition in a lean burn high brake mean effective pressure (BMEP) engine. The experimentation explored a variety of optical and electrical input parameters that when combined produced a robust spark in air. The results show peak power levels exceeding 2 MW and peak focal intensities above 400 GW/cm2. Future research avenues and current progress with the initial prototype are presented and discussed.

McIntyre, D.L.; Richardson, S.W.; Woodruff, S.D.; McMillian, M.H.; Guutam, M. (West Virginia Univ., Morgantown, WV)

2007-04-01T23:59:59.000Z

52

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)

CYCLE-BY-CYCLE COMBUSTION VARIATIONS IN SPARK-IGNITED ENGINES C.S. DAW Engineering Technology-2053 USA ABSTRACT Under constant nominal operating conditions, internal combustion engines can exhibit sub- stantial variation in combustion efficiency from one cycle to the next. Previous researchers have attempted

Tennessee, University of

53

Ethanol Blends and Engine Operating Strategy Effects on Light-Duty Spark-Ignition Engine Particle Emissions  

Science Conference Proceedings (OSTI)

Spark ignition (SI) engines with direct injection (DI) fueling can improve fuel economy and vehicle power beyond that of port fuel injection (PFI). Despite this distinct advantage, DI fueling often increases particle emissions such that SI exhaust may be subject to future particle emissions regulations. Challenges in controlling particle emissions arise as engines encounter varied fuel composition such as intermediate ethanol blends. Furthermore, modern engines are operated using unconventional breathing strategies with advanced cam-based variable valve actuation systems. In this study, we investigate particle emissions from a multi-cylinder DI engine operated with three different breathing strategies, fueling strategies and fuels. The breathing strategies are conventional throttled operation, early intake valve closing (EIVC) and late intake valve closing (LIVC); the fueling strategies are single injection DI (sDI), multi-injection DI (mDI), and PFI; and the fuels are emissions certification gasoline, E20 and E85. The results indicate the dominant factor influencing particle number concentration emissions for the sDI and mDI strategies is the fuel injection timing. Overly advanced injection timing results in particle formation due to fuel spray impingement on the piston, and overly retarded injection timing results in particle formation due to poor fuel and air mixing. In addition, fuel type has a significant effect on particle emissions for the DI fueling strategies. Gasoline and E20 fuels generate comparable levels of particle emissions, but E85 produces dramatically lower particle number concentration. The particle emissions for E85 are near the detection limit for the FSN instrument, and particle number emissions are one to two orders of magnitude lower for E85 relative to gasoline and E20. We found PFI fueling produces very low levels of particle emissions under all conditions and is much less sensitive to engine breathing strategy and fuel type than the DI fueling strategies. The particle number-size distributions for PFI fueling are of the same order for all of the breathing strategies and fuel types and are one to two orders lower than for the sDI fuel injection strategy with gasoline and E20. Remarkably, the particle emissions for E85 under the sDI fueling strategy are similar to particle emissions with a PFI fueling strategy. Thus by using E85, the efficiency and power advantages of DI fueling can be gained without generating high particle emissions.

Szybist, James P [ORNL; Youngquist, Adam D [ORNL; Barone, Teresa L [ORNL; Storey, John Morse [ORNL; Moore, Wayne [Delphi; Foster, Matthew [Delphi; Confer, Keith [Delphi

2011-01-01T23:59:59.000Z

54

Fuzzy Expert System to Estimate Ignition Timing for Hydrogen Car  

Science Conference Proceedings (OSTI)

This paper presents the application of fuzzy expert system technique as a basis to estimate ignition timing for subsequent tuning of a Toyota Corolla 4 cylinder, 1.8l hydrogen powered car. Ignition timing prediction is a typical problem to which decision ... Keywords: Fuzzy expert system, Hydrogen engine tuning, Hydrogen powered car, Ignition advance, Ignition timing

Tien Ho; Vishy Karri

2008-09-01T23:59:59.000Z

55

A comparison of ethanol and butanol as oxygenates using a direct-injection, spark-ignition (DISI) engine.  

DOE Green Energy (OSTI)

This study was designed to evaluate a 'what if' scenario in terms of using butanol as an oxygenate in place of ethanol in an engine calibrated for gasoline operation. No changes to the stock engine calibration were performed for this study. Combustion analysis, efficiency, and emissions of pure gasoline, 10% ethanol, and 10% butanol blends in a modern direct-injection four-cylinder spark-ignition engine were analyzed. Data were taken at engine speeds of 1000 rpm up to 4000 rpm with load varying from 0 N m (idle) to 150 N m. Relatively minor differences existed between the three fuels for the combustion characteristics such as heat release rate, 50% mass fraction burned, and coefficient of variation in indicated mean effective pressure at low and medium engine loads. However at high engine loads the reduced knock resistance of the butanol blend forced the engine control unit to retard the ignition timing substantially, compared with the gasoline baseline and, even more pronounced, compared with the ethanol blend. Brake specific volumetric fuel consumption, which represented a normalized volumetric fuel flow rate, was lowest for the gasoline baseline fuel due to the higher energy density. The 10% butanol blend had a lower volumetric fuel consumption compared with the ethanol blend, as expected, based on energy density differences. The results showed little difference in regulated emissions between 10% ethanol and 10% butanol. The ethanol blend produced the highest peak specific NO{sub x} due to the high octane rating of ethanol and effective antiknock characteristics. Overall, the ability of butanol to perform equally as well as ethanol from an emissions and combustion standpoint, with a decrease in fuel consumption, initially appears promising. Further experiments are planned to explore the full operating range of the engine and the potential benefits of higher blend ratios of butanol.

Wallner, T.; Miers, S. A.; McConnell, S. (Energy Systems)

2009-05-01T23:59:59.000Z

56

Particulate Matter Sampling and Volatile Organic Compound Removal for Characterization of Spark Ignited Direct Injection Engine Emissions  

Science Conference Proceedings (OSTI)

More stringent emissions regulations are continually being proposed to mitigate adverse human health and environmental impacts of internal combustion engines. With that in mind, it has been proposed that vehicular particulate matter (PM) emissions should be regulated based on particle number in addition to particle mass. One aspect of this project is to study different sample handling methods for number based aerosol measurements, specifically, two different methods for removing volatile organic compounds (VOCs). One method is a thermodenuder (TD) and the other is an evaporative chamber/diluter (EvCh). These sample handling methods have been implemented in an engine test cell with a spark ignited direct injection (SIDI) engine. The engine was designed for stoichiometric, homogeneous combustion. SIDI is of particular interest for improved fuel efficiency compared to other SI engines, however, the efficiency benefit comes with greater PM emissions and may therefore be subject to the proposed number based PM regulation. Another aspect of this project is to characterize PM from this engine in terms of particle number and composition.

Matthias, Nicholas; Farron, Carrie; Foster, David E.; Andrie, Michael; Krieger, Roger; Najt, Paul M.; Narayanaswamy, Kushal; Solomon, Arun S.; Zelenyuk, Alla

2012-01-01T23:59:59.000Z

57

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)

The exhaust gas recirculation (EGR) system has been widely used to reduce nitrogen oxide (NOx) emission, improve fuel economy and suppress knock by using the characteristics of charge dilution. However, previous studies have shown that as the EGR rate at a given engine operating condition increases, the combustion instability increases. The combustion instability increases cyclic variations resulting in the deterioration of engine performance and increasing hydrocarbon emissions. Therefore, 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, emission characteristics and second law parameters, considering combustion instability issues as EGR level increases. A parameter, called 'Fuel Fraction Burned,' was introduced as a function of the EGR percentage and used in the simulation to incorporate the combustion instability effects. A comprehensive parametric investigation was conducted to examine the effects of variations in EGR, load and speed for a 5.7 liter spark-ignition automotive engine. Variations in the thermal efficiencies, brake specific NOx emissions, average combustion temperature, mean exhaust temperature, maximum temperature and relative heat transfer as functions of exhaust gas recycle were determined for both cooled and adiabatic EGR configurations. Also effects of variations in the load and speed on thermal efficiencies, relative heat transfers and destruction of availability due to combustion were determined for 0% EGR and 20% EGR cases with both cooled and adiabatic configurations. For both EGR configurations, thermal efficiencies first increase, reach a maximum at about 16% EGR and then decrease as the EGR level increases. Thermal efficiencies are slightly higher for cooled EGR configuration than that for adiabatic configuration. Concentration of nitric oxide emissions decreases from about 2950 ppm to 200 ppm as EGR level increases from 0% to 20% for cooled EGR configuration. The cooled EGR configuration results in lower nitric oxide emissions relative to the adiabatic EGR configuration. Also second law parameters show the expected trends as functions of EGR. Brake thermal efficiency is higher for the 20% EGR case than that for the no EGR case over the range of load (0 to WOT) and speed (600 rpm to 6000 rpm). Predictions made from the simulation were compared with some of the available experimental results. Predicted thermal efficiencies showed a similar trend when compared to the available experimental data. Also, percentage of unused fuel availability increases as the EGR level increases, and it can be seen as one of the effects of deteriorating combustion quality as the EGR level increases.

Shyani, Rajeshkumar Ghanshyambhai

2008-08-01T23:59:59.000Z

58

Potential benefits of oxygen-enriched intake air in a vehicle powered by a spark-ignition engine  

DOE Green Energy (OSTI)

A production vehicle powered by a spark-ignition engine (3.1-L Chevrolet Lumina, model year 1990) was tested. The test used oxygen-enriched intake air containing 25 and 28% oxygen by volume to determine (1) if the vehicle would run without difficulties and (2) if emissions benefits would result. Standard Federal Test Procedure (FTP) emissions test cycles were run satisfactorily. Test results of catalytic converter-out emissions (emissions out of the converter) showed that both carbon monoxide and hydrocarbons were reduced significantly in all three phases of the emissions test cycle. Test results of engine-out emissions (emissions straight out of the engine, with the converter removed) showed that carbon monoxide was significantly reduced in the cold phase. All emission test results were compared with those for normal air (21% oxygen). The catalytic converter also had an improved carbon monoxide conversion efficiency under the oxygen-enriched-air conditions. Detailed results of hydrocarbon speciation indicated large reductions in 1,3-butadiene, formaldehyde, acetaldehyde, and benzene from the engine with the oxygen-enriched air. Catalytic converter-out ozone was reduced by 60% with 25%-oxygen-content air. Although NO{sub x} emissions increased significantly, both for engine-out and catalytic converter-out emissions, we anticipate that they can be ameliorated in the near future with new control technologies. The automotive industry currently is developing exhaust-gas control technologies for an oxidizing environment; these technologies should reduce NO{sub x} emissions more efficiently in vehicles that use oxygen-enriched intake air. On the basis of estimates made from current data, several production vehicles that had low NO{sub x} emissions could meet the 2004 Tier II emissions standards with 25%-oxygen-content air.

Ng, H.K.; Sekar, R.R.

1994-04-01T23:59:59.000Z

59

SolarBridge Technologies formerly SmartSpark Energy Systems | Open Energy  

Open Energy Info (EERE)

SolarBridge Technologies formerly SmartSpark Energy Systems SolarBridge Technologies formerly SmartSpark Energy Systems Jump to: navigation, search Name SolarBridge Technologies (formerly SmartSpark Energy Systems) Place Austin, Texas Zip 78731 Sector Solar Product Developing a micro-inverter for residential solar panels, and charge equalisers to improve life for battery-powered equipment. References SolarBridge Technologies (formerly SmartSpark Energy Systems)[1] LinkedIn Connections CrunchBase Profile No CrunchBase profile. Create one now! This article is a stub. You can help OpenEI by expanding it. SolarBridge Technologies (formerly SmartSpark Energy Systems) is a company located in Austin, Texas . References ↑ "SolarBridge Technologies (formerly SmartSpark Energy Systems)" Retrieved from "http://en.openei.org/w/index.php?title=SolarBridge_Technologies_formerly_SmartSpark_Energy_Systems&oldid=351355"

60

Spark gap switch system with condensable dielectric gas  

DOE Patents (OSTI)

A spark gap switch system is disclosed which is capable of operating at a high pulse rate comprising an insulated switch housing having a purging gas entrance port and a gas exit port, a pair of spaced apart electrodes each having one end thereof within the housing and defining a spark gap therebetween, an easily condensable and preferably low molecular weight insulating gas flowing through the switch housing from the housing, a heat exchanger/condenser for condensing the insulating gas after it exits from the housing, a pump for recirculating the condensed insulating gas as a liquid back to the housing, and a heater exchanger/evaporator to vaporize at least a portion of the condensed insulating gas back into a vapor prior to flowing the insulating gas back into the housing.

Thayer, III, William J. (Kent, WA)

1991-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ignition system spark" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Active flow control for maximizing performance of spark ignited stratified charge engines. Final report  

DOE Green Energy (OSTI)

Reducing the cycle-to-cycle variability present in stratified-charge engines is an important step in the process of increasing their efficiency. As a result of this cycle-to-cycle variability, fuel injection systems are calibrated to inject more fuel than necessary, in an attempt to ensure that the engines fire on every cycle. When the cycle-to-cycle variability is lowered, the variation of work per cycle is reduced and the lean operating limit decreases, resulting in increased fuel economy. In this study an active flow control device is used to excite the intake flow of an engine at various frequencies. The goal of this excitation is to control the way in which vortices shed off of the intake valve, thus lowering the cycle-to-cycle variability in the flow field. This method of controlling flow is investigated through the use of three engines. The results of this study show that the active flow control device did help to lower the cycle-to-cycle variability of the in-cylinder flow field; however, the reduction did not translate directly into improved engine performance.

Fedewa, Andrew; Stuecken, Tom; Timm, Edward; Schock, Harold J.; Shih, Tom-I.P.; Koochesfahani, Manooch; Brereton, Giles

2002-10-15T23:59:59.000Z

62

IMPROVEMENT TO PIPELINE COMPRESSOR ENGINE RELIABILITY THROUGH RETROFIT MICRO-PILOT IGNITION SYSTEM  

Science Conference Proceedings (OSTI)

This report documents a 3-year research program conducted by the Engines & Energy Conversion Laboratory (EECL) at Colorado State University (CSU) to develop micropilot ignition systems for existing pipeline compressor engines. Research activities for the overall program were conducted with the understanding that the efforts are 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 objective for Phase I was to demonstrate the feasibility of micropilot ignition for large bore, slow speed engines operating at low compression ratios under laboratory conditions at the EECL. 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. The four-cylinder prototype data was encouraging for the micro-pilot ignition technology when compared to spark ignition. The objective for Phase II was to further develop and optimize the micropilot ignition system at the EECL for large bore, slow speed engines operating at low compression ratios. The primary elements of Micropilot Phase II were to evaluate the results for the 4-cylinder system prototype developed for Phase I, then optimize this system and prepare the technology for the field demonstration phase in Year 3. In all, there were twelve (12) tasks defined and executed to support objectives in a stepwise fashion. The optimized four-cylinder system data demonstrated significant progress compared to Phase I results, as well as traditional spark ignition systems. These laboratory results were enhanced, then verified via a field demonstration project during Phase III of the Micropilot Ignition program. An Implementation Team of qualified engine retrofit service providers was assembled to install the retrofit micropilot ignition system on an engine operated by El Paso Pipeline Group at a compressor station near Window Rock, Arizona. Testing of this demonstration unit showed that the same benefits identified by laboratory testing at CSU, i.e., reduced fuel consumption and exhaust emissions (NOx, THC, CO, and CH2O). Commercialization of the retrofit micropilot ignition technology is awaiting a ''market pull'', which is expected to materialize as the results of the field demonstration become known and accepted. The Implementation Team, comprised of Woodward Governor Company, Enginuity LLC, Hoerbiger Corporation of America, and DigiCon Inc., has direct experience with the technology development and implementation, and stands ready to promote and commercialize the retrofit micropilot ignition system.

Scott Chase; Daniel Olsen; Ted Bestor

2005-05-01T23:59:59.000Z

63

RAILPLUG IGNITION SYSTEM FOR ENHANCED ENGINE PERFORMANCE AND REDUCED MAINTENANCE  

DOE Green Energy (OSTI)

During the first year of this project, three experimental subtasks and four modeling subtasks were scheduled to begin. Five of these 7 subtasks were scheduled for completion by the end of the first year. Both experimental tasks were completed on schedule. No experimental data were scheduled for the first year. The four modeling tasks are progressing well. However, two of the numerical tasks have been delayed somewhat. A simplified plasma kinetics mechanism was developed and tested against a detailed model. The agreement was quite good. A simplified kinetics mechanism for flame propagation was also developed and validated via comparisons against an elementary kinetics mechanism. Again, the agreement was quite good. The 2D spark ignition process model was exercised to ensure stability but the 3D version was not completed. Excellent progress was made on the ignition circuit model, but it is not yet finished. The delays in these two subtasks are not expected to impact the schedule for the overall project.

Ron Matthews

2003-08-20T23:59:59.000Z

64

A Review of Sub-Scale Test Methods to Evaluate the Friction and Wear of Ring and Liner Materials for Spark- and Compression Ignition Engines  

Science Conference Proceedings (OSTI)

A review was conducted of past laboratory-scale test methods and to assess their validity for ranking materials and lubricants for use as piston and liner materials in compression-ignition (CI) and spark-ignition (SI) engines. Most of the previous work was aimed at simulating SI engine environments. This report begins with a discussion of the numerous factors that can affect the validity of an approach to simulating engine conditions in a laboratory. These include not only mechanical, chemical and thermal factors, but also human factors as regards how the vehicle is operated and maintained. The next section provides an annotated review of open literature publications that address the issues of laboratory simulation of engine components. A comparison of these studies indicates a lack of sufficient standardization in procedures to enable a systematic comparison of one publication to another. There were just a few studies that compared several laboratory test methods to engine test results, and these indicated that some test methods correlate, at least qualitatively, better than others. The last section provides a series of recommendations for improving the accuracy and validity of laboratory-scale simulations of engine behavior. It became clear that much of the engine wear damage occurs during start-up when the engine is cold, and this calls into the question the usefulness of test methods that attempt to simulate steady-state running conditions. It is recommended that a new standard test method, perhaps developed with the help of the ASTM wear and erosion committee, be developed. It would use cold start-up conditions in the presence of degraded oil, or simulated degraded oil.

Blau, P.J.

2002-01-22T23:59:59.000Z

65

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

Science Conference Proceedings (OSTI)

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.

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

2010-03-03T23:59:59.000Z

66

Overview and Status of the Power Conditioning System for the National Ignition Facility  

DOE Green Energy (OSTI)

The National Ignition Facility (NIF) Power Conditioning System (PCS) is a modular capacitive energy storage system that provides over 34 kilojoules of energy to each of the nearly 8000 flashlamps in the NIF laser. Up to 400 megajoules of energy can be stored in the NIF PCS system, discharged through spark gaps and delivered to the flashlamps through a coaxial transmission line system requiring nearly 100 miles of high-voltage cable. The NIF PCS has been under development for nearly 4 years. During this time, the system was developed and designed by Sandia National Laboratory in Albuquerque, NM (SNLA) in conjunction with Lawrence Livermore National Laboratory (LLNL). Extensive reliability testing was performed at SNLA on the First Article NIF Test Module (FANTM) test facility and design improvements were implemented based on FANTM test results, leading to the final design presently undergoing system reliability testing at LLNL. Low-cost energy-storage capacitors, charging power supplies, and reliable, fault-tolerant components were developed through partnerships with numerous contractors. Extensive reliability and fault testing of components has also been performed. This paper will provide an overview of the many efforts that have culminated in the final design of the NIF PCS. The PCS system design will be described and the cost tradeoffs discussed. Plans for fabrication and installation of the NIF PCS system over the next 6 years will be presented.

Newton, M A; Fulkerson, E S; Hulsey, S D; Kamm, R E; Pendleton, D L; Petersen, D E; Smith, C R; Ullery, G T; McKay, P F; Moore, W B; Muirhead, D A

2001-09-11T23:59:59.000Z

67

National Ignition Facility Project Completion and Control System Status  

SciTech Connect

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.

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

68

Fabrication and testing of an enhanced ignition system to reduce cold-start emissions in an ethanol (E85) light-duty truck engine  

DOE Green Energy (OSTI)

This report describes an experimental investigation of the potential for an enhanced ignition system to lower the cold-start emissions of a light-duty vehicle engine using fuel ethanol (commonly referred to as E85). Plasma jet ignition and conventional inductive ignition were compared for a General Motors 4-cylinder, alcohol-compatible engine. Emission and combustion stability measurements were made over a range of air/fuel ratios and spark timing settings using a steady-state, cold-idle experimental technique in which the engine coolant was maintained at 25 C to simulate cold-running conditions. These tests were aimed at identifying the degree to which calibration strategies such as mixture enleanment and retarded spark timing could lower engine-out hydrocarbon emissions and raise exhaust temperatures, as well as determining how such calibration changes would affect the combustion stability of the engine (as quantified by the coefficient of variation, or COV, of indicated mean effective pressure calculated from successive cylinder pressure measurements). 44 refs., 39 figs.

Gardiner, D.; Mallory, R.; Todesco, M. [Nexum Research Corp., Kingston, Ontario (Canada). Thermotech Engineering Div.

1997-09-01T23:59:59.000Z

69

Laser Ignition  

NLE Websites -- All DOE Office Websites (Extended Search)

Laser Ignition Laser Ignition Laser Ignition 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. Available for thumbnail of Feynman Center (505) 665-9090 Email Laser Ignition 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 two embodiments the beam from the excitation light source is split with a portion of it going to the ignitor laser and a second portion

70

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

SciTech Connect

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. A discussion is presented of the use of a multiplexed fiber optic data transmission system and low cost digital stepper motors for control functions. Techniques are discussed which allow TTL and CMOS semiconductor circuits to survive the destructive sparks which can occur in the 1.5 Mv preaccelerator. 5 refs.

Bogaty, J.M.; Zolecki, R.

1981-06-01T23:59:59.000Z

71

The Neutron Imaging System Fielded at the National Ignition Facility  

SciTech Connect

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.

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

72

The Fuel Control System and Performance Optimization of a Spark-Ignition LPG Engine  

Science Conference Proceedings (OSTI)

This paper presents an approach to control air fuel ratio of a Liquefied Petroleum Gas (LPG) automotive engine. The optimization of compression ratio is also described in this paper. HC, CO & NOx emissions of LPG engines can be reduced after the application ... Keywords: control, LPG engine, air fuel ratio, optimization

Hongwei Cui

2009-04-01T23:59:59.000Z

73

Spark Spread  

Gasoline and Diesel Fuel Update (EIA)

Spark Spread Spark Spread Figure 1 Source: U.S. Energy Information Administration, based on SNL Energy. The spark spread is a common metric for estimating the profitability of natural gas-fired electric generators. The spark spread is the difference between the price received by a generator for electricity produced and the cost of the natural gas needed to produce that electricity. It is typically calculated using daily spot prices for natural gas and power at various regional trading points. The chart above shows spark spreads during 2012, calculated for four locations around the United States. Spark spreads tend to be fairly volatile, more so than crack spreads in petroleum markets, largely because of the volatility of wholesale electric power prices, which vary widely

74

HYDROGEN IGNITION MECHANISM FOR EXPLOSIONS IN NUCLEAR FACILITY PIPE SYSTEMS  

DOE Green Energy (OSTI)

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 exist. Pipe ruptures at nuclear facilities were attributed to hydrogen explosions inside pipelines, in nuclear facilities, i.e., Hamaoka, Nuclear Power Station in Japan, and Brunsbuettel in Germany. Prior to these accidents an ignition source for hydrogen was questionable, but these accidents, demonstrated that a mechanism was, in fact, available to initiate combustion and explosion. 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.

Leishear, R

2010-05-02T23:59:59.000Z

75

PF Coil System Comparisons for a Compact Ignition Device  

Science Conference Proceedings (OSTI)

The Compact Ignition Tokamak Program / Proceedings of the Seveth Topical Meeting on the Technology of Fusion Energy (Reno, Nevada, June 15–19, 1986)

R.D. Pillsbury; Jr.; J.H. Schultz; R.J. Thome

76

Prospectus of ignition enhancement in a two-stroke SI engine  

DOE Green Energy (OSTI)

Conventional two-stroke spark-ignition (SI) engines have difficulty meeting the ignition requirements of lean fuel-air mixtures and high compression ratios, due to their breaker operated, magneto-coil ignition systems. In the present work, a breakerless, high-energy electronic ignition system was developed and tested with and without a platinum-tipped electrode spark plug. The high-energy ignition system showed an improved lean-burn capability at high compression ratios relative to the conventional ignition system. At a high compression ratio of 9:1 with lean fuel-air mixtures, the maximum percentage improvement in the brake thermal efficiency was about 16.5% at 2.7 kW and 3000 rpm. Cylinder peak pressures-were higher ignition delay was lower, and combustion duration was shorter at both normal and high compression ratios. Combustion stability as measured by the coefficient of variation in peak cylinder pressure was also considerably improved with the high-energy ignition system.

Manivannan, P.V.; Ramesh, A. [Indian Inst. of Tech., New Delhi (India); Poola, R.B. [Argonne National Lab., IL (United States); Dhinadgar, S.J. [Tata Engineering & Locomotive Co., New Delhi (India)

1995-12-01T23:59:59.000Z

77

Fuel effects in homogeneous charge compression ignition (HCCI) engines  

E-Print Network (OSTI)

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 ...

Angelos, John P. (John Phillip)

2009-01-01T23:59:59.000Z

78

Nitrogen spark denoxer  

DOE Patents (OSTI)

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.

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

1997-01-01T23:59:59.000Z

79

Surface breakdown igniter for mercury arc devices  

DOE Patents (OSTI)

Surface breakdown igniter comprises a semiconductor of medium resistivity which has the arc device cathode as one electrode and has an igniter anode electrode so that when voltage is applied between the electrodes a spark is generated when electrical breakdown occurs over the surface of the semiconductor. The geometry of the igniter anode and cathode electrodes causes the igniter discharge to be forced away from the semiconductor surface.

Bayless, John R. (Malibu, CA)

1977-01-01T23:59:59.000Z

80

Argonne TTRDC - Engines - Home - combustion, compression ignition,  

NLE Websites -- All DOE Office Websites (Extended Search)

* Combustion Visualization * Combustion Visualization * Compression-Ignition * Emissions Control * Fuel Injection and Sprays * Idling * Multi-Dimensional Modeling * Particulate Matter * Spark Ignition Green Racing GREET Hybrid Electric Vehicles Hydrogen & Fuel Cells Materials Modeling, Simulation & Software Plug-In Hybrid Electric Vehicles PSAT Smart Grid Student Competitions Technology Analysis Transportation Research and Analysis Computing Center Working With Argonne Contact TTRDC Engines Omnivorous engine tested by Thomas Wallner Thomas Wallner tests the omnivorous engine, a type of spark-ignition engine. Argonne's engine research is contributing to advances in technology that will impact the use of conventional and alternative fuels and the design of advanced technology vehicles. Compression Ignition

Note: This page contains sample records for the topic "ignition system spark" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

A fuzzy diagnosis and advice system for optimization of emissions and fuel consumption  

Science Conference Proceedings (OSTI)

In this study, a fuzzy expert system has been developed, which is used for defining possible fuel system faults, ignition system faults, intake valve and exhaust valve faults and refers solution advice for these faults, which uses measurements of CO, ... Keywords: Diagnosis software, Emissions, Fuzzy expert systems, Spark ignition engine

Yavuz Kilagiz; Ahmet Baran; Zerrin Yildiz; Murat Çetin

2005-02-01T23:59:59.000Z

82

RAILPLUG IGNITION SYSTEM FOR ENHANCED ENGINE PERFORMANCE AND REDUCED MAINTENANCE  

DOE Green Energy (OSTI)

During the first 18 months of this project, four experimental subtasks were to have begun but only one of these was to have been completed. Additionally, five modeling subtasks were scheduled to begin, four of which were to have been completed. We are on schedule for all but one of these subtasks. All four experimental tasks are progressing on schedule. Initial durability tests were completed. The conclusions drawn from this first round of durability tests are being used to design the next set of tests. Initial baseline engine data were acquired and showed that the engine selected for this task behaves as hoped. However, the dyno controller is inadequate. The engine will be moved to another dyno during the near future. The modeling tasks are also progressing well. A model for the dynamic response of the ignition circuit was developed and validated. Two technical papers resulting from this model were submitted for publication. Development of a model for the railplug ignition process was begun but was not scheduled for completion. Progress on this task consisted of two subtasks. First, a railplug circuit model was also developed and validated. Second, a model was developed for the physics that govern railplug performance. This initial model incorporated only the effects of the Lorentz force on arc movement. From this model, it is concluded that thermal expansion is important to the performance of railplugs. Thermal expansion, and other physical effects, will be added to the model in the near future. We delayed the development of a 3D model for the ignition process, until near the end of the project because of the computational time requirements. We can learn most of the important lessons from the 2D model. Delay of this subtask will not affect the timely completion of the project.

Ron Matthews

2003-09-19T23:59:59.000Z

83

Advanced aircraft ignition CRADA final report  

DOE Green Energy (OSTI)

Conventional commercial and military turbo-jet aircraft engines use capacitive discharge ignition systems to initiate fuel combustion. The fuel-rich conditions required to ensure engine re-ignition during flight yield less than optimal engine performance, which in turn reduces fuel economy and generates considerable pollution in the exhaust. Los Alamos investigated two approaches to advanced ignition: laser based and microwave based. The laser based approach is fuel ignition via laser-spark breakdown and via photo-dissociation of fuel hydrocarbons and oxygen. The microwave approach involves modeling, and if necessary redesigning, a combustor shape to form a low-Q microwave cavity, which will ensure microwave breakdown of the air/fuel mixture just ahead of the nozzle with or without a catalyst coating. This approach will also conduct radio-frequency (RF) heating of ceramic elements that have large loss tangents. Replacing conventional systems with either of these two new systems should yield combustion in leaner jet fuel/air mixtures. As a result, the aircraft would operate with (1) considerable less exhaust pollution, (2) lower engine maintenance, and (3) significantly higher fuel economy.

Early, J.W.

1997-03-01T23:59:59.000Z

84

Closed-loop, variable-valve-timing control of a controlled-auto-ignition engine  

E-Print Network (OSTI)

The objective of this study was to develop a closed-loop controller for use on a Controlled-Auto- Ignition (CAI) / Spark-Ignition (SI) mixed mode engine equipped with a variable-valve-timing (VVT) mechanism. The controller ...

Matthews, Jeffrey A., 1970-

2004-01-01T23:59:59.000Z

85

RAILPLUG IGNITION SYSTEM FOR ENHANCED ENGINE PERFORMANCE AND REDUCED MAINTENANCE  

DOE Green Energy (OSTI)

During the first 6 months of this project, four subtasks were scheduled. Two of these commenced earlier than originally proposed. The experimental task, development of new railplug designs, was completed on schedule. The three numerical subtasks were not completed on schedule. However, this is not expected to affect the capability to complete the overall project on schedule. Because we are early in the project, no results or conclusions were generated. Our progress included development of new railplug geometries, to be tested during the second 6 months of the project, and development of an initial 3D model. Progress was also made in development of the appropriate chemical kinetics and generation of a model for the ignition circuit.

Ron Matthews

2003-05-29T23:59:59.000Z

86

An approach for modeling the valve train system to control the homogeneous combustion in a compression ignition engine  

Science Conference Proceedings (OSTI)

This paper presents an approach for modeling the valve train system to obtain a homogeneous charge compression ignition (HCCI) engine from a gasoline engine. The HCCI engines use different indirect strategies to control the start of the combustion. The ... Keywords: exhaust gas recirculation, homogeneous charge compression ignition, variable valve timing

Radu Cosgarea; Corneliu Cofaru; Mihai Aleonte; Maria Luminita Scutaru; Liviu Jelenschi; Gabriel Sandu

2011-04-01T23:59:59.000Z

87

Engines - Spark Ignition Engines - Hydrogen Engines  

NLE Websites -- All DOE Office Websites (Extended Search)

large-scale hydrogen infrastructure by using the well-known and widely used internal combustion engine as the device that transforms the energy stored in hydrogen into motion. The...

88

Development of an engine fuel and spark controller  

E-Print Network (OSTI)

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 by the user for engine tuning purposes. The controller was designed to operate using a speed-throttle fuel map, with acceleration enrich, meet and other fuel compensating factors. A paired double-tiring strategy was adapted to avoid the complications associated with sequential fuel injection. The ECU utilized a Motorola 68HC16 development board, as well as special injector and ignition driver circuits. The software was designed to be primarily interrupt driven, with a task manager to arbitrate among other tasks. A user interface program, which runs on a PC, allows the user to instantly alter operating parameters in the ECU during engine tuning and development. The controller was tested on a Yamaha YZF 600 motorcycle engine with a custom intake manifold and fuel injection system. The fuel and spark maps and other parameters were configured for this engine by using the user interface. Dynamometer testing verities that engine performance with this ECU meets design specifications.

Suter, William Gregory

1999-01-01T23:59:59.000Z

89

Laser Ignition  

NLE Websites -- All DOE Office Websites (Extended Search)

Ignition Laser Ignition 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...

90

A HYDROGEN IGNITION MECHANISM FOR EXPLOSIONS IN NUCLEAR FACILITY PIPING SYSTEMS  

SciTech Connect

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.

Leishear, R.

2013-03-28T23:59:59.000Z

91

IMPROVEMENT TO PIPELINE COMPRESSOR ENGINE RELIABILITY THROUGH RETROFIT MICRO-PILOT IGNITION SYSTEM -- PHASE III  

Science Conference Proceedings (OSTI)

This report documents the third year's effort towards a 3-year program conducted by the Engines & Energy Conversion Laboratory (EECL) at Colorado State University (CSU) to develop micropilot ignition systems for existing pipeline compressor engines. Research activities for the overall program were conducted with the understanding that the efforts are to result in a commercial product to capture and disseminate the efficiency and environmental benefits of this new technology. 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. Two earlier phases of development precede this report. The objective for Phase I was to demonstrate the feasibility of retrofit micropilot ignition (RMI) systems for large bore, slow speed engines operating at low compression ratios under laboratory conditions at the EECL. The objective for Phase II was to further develop and optimize the micropilot ignition system at the EECL for large bore, slow speed engines operating at low compression ratios. These laboratory results were enhanced, then verified via a field demonstration project during Phase III of the Micropilot Ignition program. An Implementation Team of qualified engine retrofit service providers was assembled to install the retrofit micropilot ignition system for an engine operated by El Paso Pipeline Group at a compressor station near Window Rock, Arizona. Testing of this demonstration unit showed that the same benefits identified by laboratory testing at CSU, i.e., reduced fuel consumption and exhaust emissions (NOx, THC, CO, and CH2O). Installation efforts at Window Rock were completed towards the end of the budget period, which did not leave sufficient time to complete the durability testing. These efforts are ongoing, with funding provided by El Paso Pipeline Group, and the results will be documented in a report. Commercialization of the retrofit micropilot ignition (RMI) technology is awaiting a ''market pull'', which is expected to materialize as the results of the field demonstration become known and accepted. The Implementation Team, comprised of Woodward Governor Company, Enginuity LLC, Hoerbiger Corporation of America, and DigiCon Inc., has direct experience with the technology development and implementation, and stands ready to promote and commercialize the RMI system.

Scott Chase; Daniel Olsen; Ted Bestor

2005-03-01T23:59:59.000Z

92

US Department of Energy - Office of FreedomCar and Vehicle Technologies and US Centers for Disease Control and Prevention - National Institute for Occupational Safety and Health Inter-Agency Agreement Research on "The Analysis of Genotoxic Activities of Exhaust Emissions from Mobile Natural Gas, Diesel, and Spark-Ignition Engines"  

DOE Green Energy (OSTI)

The US Department of Energy-Office of Heavy Vehicle Technologies (now the DOE-Office of FreedomCar and Vehicle Technologies) signed an Interagency Agreement (IAA) with National Institute for Occupational Safety and Health (NIOSH), No.01-15 DOE, 9/4/01, for 'The analysis of genotoxic activities of exhaust emissions from mobile natural gas, diesel, and spark-ignition engines'; subsequently modified on 3/27/02 (DOE IAG No.01-15-02M1); subsequently modified 9/02/03 (IAA Mod No. 01-15-03M1), as 'The analysis of genotoxic activities of exhaust emissions from mobile internal combustion engines: identification of engine design and operational parameters controlling exhaust genotoxicity'. The DOE Award/Contract number was DE-AI26-01CH11089. The IAA ended 9/30/06. This is the final summary technical report of National Institute for Occupational Safety and Health research performed with the US Department of Energy-Office of FreedomCar and Vehicle Technologies under that IAA: (A) NIOSH participation was requested by the DOE to provide in vitro genotoxicity assays of the organic solvent extracts of exhaust emissions from a suite of in-use diesel or spark-ignition vehicles; (B) research also was directed to develop and apply genotoxicity assays to the particulate phase of diesel exhaust, exploiting the NIOSH finding of genotoxicity expression by diesel exhaust particulate matter dispersed into the primary components of the surfactant coating the surface of the deep lung; (C) from the surfactant-dispersed DPM genotoxicity findings, the need for direct collection of DPM aerosols into surfactant for bioassay was recognized, and design and developmental testing of such samplers was initiated.

William E. Wallace

2006-09-30T23:59:59.000Z

93

Spent N fuel project preliminary saftey evaluation of the cold vacuum drying system -- calculations for the flammable gas ignition scenario  

DOE Green Energy (OSTI)

For a preliminary safety evaluation of the Cold Vacuum Drying System, calculations for the flammable gas ignition scenario are provided. Hydrogen buildup from uranium corrosion in the MCO followed by inadvertent injection of oxygen and the presence of an ignition source leads to hydrogen deflagration that over pressurizes and releases radioactive particulate matter to the environment. The adiabatic flame temperature, MCO pressure and source term are calculated.

Scott, D.L.

1996-06-12T23:59:59.000Z

94

Target Diagnostic Control System Implementation for the National Ignition Facility  

Science Conference Proceedings (OSTI)

The extreme physics of targets shocked by NIF's 192-beam laser are observed by a diverse suite of diagnostics. Many diagnostics are being developed by collaborators at other sites, but ad hoc controls could lead to unreliable and costly operations. A Diagnostic Control System (DCS) framework for both hardware and software facilitates development and eases integration. Each complex diagnostic typically uses an ensemble of electronic instruments attached to sensors, digitizers, cameras, and other devices. In the DCS architecture each instrument is interfaced to a low-cost Windows XP processor and Java application. Each instrument is aggregated with others as needed in the supervisory system to form an integrated diagnostic. The Java framework provides data management, control services and operator GUI generation. DCS instruments are reusable by replication with reconfiguration for specific diagnostics in XML. Advantages include minimal application code, easy testing, and high reliability. Collaborators save costs by assembling diagnostics with existing DCS instruments. This talk discusses target diagnostic instrumentation used on NIF and presents the DCS architecture and framework.

Shelton, R T; Kamperschroer, J H; Lagin, L J; Nelson, J R; O'Brien, D W

2010-05-12T23:59:59.000Z

95

Initial Activation and Operation of the Power Conditioning System for the National Ignition Facility  

DOE Green Energy (OSTI)

The NIF Power Conditioning System (PCS) resides in four Capacitor Bays, supplying energy to the Master and Power Amplifiers which reside in the two adjacent laser bays. Each capacitor bay will initially house 48 individual power conditioning modules, shown in Figure 2, with space reserved for expansion to 54 modules. The National Ignition Facility (NIF) Power Conditioning System (PCS) is a modular capacitive energy storage system that will be capable of storing nearly 400 MJ of electrical energy and delivering that energy to the nearly 8000 flashlamps in the NIF laser. The first sixteen modules of the power conditioning system have been built, tested and installed. Activation of the first nine power conditioning modules has been completed and commissioning of the first ''bundle'' of laser beamlines has begun. This paper will provide an overview of the power conditioning system design and describe the status and results of initial testing and activation of the first ''bundle'' of power conditioning modules.

Newton, M A; Kamm, R E; Fulkerson, E S; Hulsey, S D; Lao, N; Parrish, G L; Pendleton, D L; Petersen, D E; Polk, M; Tuck, J M; Ullery, G T; Moore, W B

2003-08-20T23:59:59.000Z

96

IGNITION IMPROVEMENT OF LEAN NATURAL GAS MIXTURES  

DOE Green Energy (OSTI)

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.

Jason M. Keith

2005-02-01T23:59:59.000Z

97

Use of the target diagnostic control system in the National Ignition Facility  

SciTech Connect

The extreme physics of targets shocked by NIF's 192-beam laser are observed by a diverse suite of diagnostics including optical backscatter, time-integrated, time resolved and gated X-ray sensors, laser velocity interferometry, and neutron time of flight. Diagnostics to diagnose fusion ignition implosion and neutron emissions have been developed. A Diagnostic Control System (DCS) for both hardware and software facilitates development and eases integration. Each complex diagnostic typically uses an ensemble of electronic instruments attached to sensors, digitizers, cameras, and other devices. In the DCS architecture each instrument is interfaced to a low-cost Window XP processor and Java application. Instruments are aggregated as needed in the supervisory system to form an integrated diagnostic. The Java framework provides data management, control services and operator GUI generation. During the past several years, over thirty-six diagnostics have been deployed using this architecture in support of the National Ignition Campaign (NIC). The DCS architecture facilitates the expected additions and upgrades to diagnostics as more experiments are performed. This paper presents the DCS architecture, framework and our experiences in using it during the NIC to operate, upgrade and maintain a large set of diagnostic instruments.

Shelton, R; Lagin, L; Nelson, J

2011-07-25T23:59:59.000Z

98

Spark Plasma Sintering  

Science Conference Proceedings (OSTI)

Oct 21, 2010 ... Coupled Electro-Thermo-Mechanical Analysis of Conventional (SPS) and Free Pressureless (FPSPS) Spark-Plasma Sintering: Eugene ...

99

Spark Spread - Energy Information Administration  

U.S. Energy Information Administration (EIA)

The spark spread is a common metric for estimating the profitability of natural gas-fired electric generators. The spark spread is the difference between the price ...

100

2011 Status of the Automatic Alignment System for the National Ignition Facility  

SciTech Connect

Automated alignment for the National Ignition Facility (NIF) is accomplished using a large-scale parallel control system that directs 192 laser beams along the 300-m optical path. The beams are then focused down to a 50-micron spot in the middle of the target chamber. The entire process is completed in less than 50 minutes. The alignment system commands 9,000 stepping motors for highly accurate adjustment of mirrors and other optics. 41 control loops per beamline perform parallel processing services running on a LINUX cluster to analyze high-resolution images of the beams and their references. This paper describes the status the NIF automatic alignment system and the challenges encountered as NIF development has transitioned from building the laser, to becoming a research project supporting a 24 hour, 7 day laser facility. NIF is now a continuously operated system where performance monitoring is increasingly more critical for operation, maintenance, and commissioning tasks. Equipment wear and the effects of high energy neutrons from fusion experiments are issues which alter alignment efficiency and accuracy. New sensors needing automatic alignment assistance are common. System modifications to improve efficiency and accuracy are prevalent. Handling these evolving alignment and maintenance needs while minimizing the impact on NIF experiment schedule is expected to be an on-going challenge for the planned 30 year operational life of NIF.

Wilhelmsen, K; Awwal, A; Burkhart, S; McGuigan, D; Kamm, V M; Leach, R; Lowe-Webb, R; Wilson, R

2011-07-19T23:59:59.000Z

Note: This page contains sample records for the topic "ignition system spark" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Advanced ignition and propulsion technology program  

DOE Green Energy (OSTI)

This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Reliable engine re-ignition plays a crucial role in enabling commercial and military aircraft to fly safely at high altitudes. This project addressed research elements critical to the optimization of laser-based igniter. The effort initially involved a collaborative research and development agreement with B.F. Goodrich Aerospace and Laser Fare, Inc. The work involved integrated experiments with theoretical modeling to provide a basic understanding of the chemistry and physics controlling the laser-induced ignition of fuel aerosols produced by turbojet engine injectors. In addition, the authors defined advanced laser igniter configurations that minimize laser packaging size, weight, complexity and power consumption. These innovative ignition concepts were shown to reliably ignite jet fuel aerosols over a broad range of fuel/air mixture and a t fuel temperatures as low as -40 deg F. The demonstrated fuel ignition performance was highly superior to that obtained by the state-of-the-art, laser-spark ignition method utilizing comparable laser energy. The authors also developed a laser-based method that effectively removes optically opaque deposits of fuel hydrocarbon combustion residues from laser window surfaces. Seven patents have been either issued or are pending that resulted from the technology developments within this project.

Oldenborg, R.; Early, J.; Lester, C.

1998-11-01T23:59:59.000Z

102

Plasma jet ignition device  

DOE Patents (OSTI)

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.

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

103

The national ignition facility: early operational experience with a large Ada control system  

Science Conference Proceedings (OSTI)

The National Ignition Facility (NIF) currently under construction at the University of California Lawrence Livermore National Laboratory (LLNL) is a 192-beam, 1.8-Megajoule, 500-Terawatt laser being built by the Department of Energy and the National ...

Robert W. Carey; Paul J. Van Arsdall; John P. Woodruff

2002-12-01T23:59:59.000Z

104

Performance Improvements to the Neutron Imaging System at the National Ignition Facility  

SciTech Connect

A team headed by LANL and including many members from LLNL and NSTec LO and NSTec LAO fielded a neutron imaging system (NIS) at the National Ignition Facility at the start of 2011. The NIS consists of a pinhole array that is located 32.5 cm from the source and that creates an image of the source in a segmented scintillator 28 m from the source. The scintillator is viewed by two gated, optical imaging systems: one that is fiber coupled, and one that is lens coupled. While there are a number of other pieces to the system related to pinhole alignment, collimation, shielding and data acquisition, those pieces are discussed elsewhere and are not relevant here. The system is operational and has successfully obtained data on more that ten imaging shots. This remainder of this whitepaper is divided in five main sections. In Section II, we identify three critical areas of improvement that we believe should be pursued to improve the performance of the system for future experiments: spatial resolution, temporal response and signal-to-noise ratio. In Section III, we discuss technologies that could be used to improve these critical performance areas. In Section IV, we describe a path to evolve the current system to achieve improved performance with minimal impact on the ability of the system to operate on shots. In Section V, we discuss the abilities, scope and timescales of the current teams and the Commissariat energie atomique (CEA). In Section VI, we summarize and make specific recommendations for collaboration on improvements to the NIS.

Fittinghoff, D N; Bower, D E; Drury, O B; Dzenitis, J M; Hatarik, R; Merrill, F E; Grim, G P; Wilde, C H; Wilson, D C; Landoas, O; Caillaud, T; Bourgade, J; Buckles, R A; Lee, J; Weiss, P B

2011-09-26T23:59:59.000Z

105

Optical design of the National Ignition Facility main laser and switchyard/target area beam transport system  

SciTech Connect

The optical design of the main laser and transport mirror sections of the National Ignition Facility are described. For the main laser the configuration, layout constraints, multiple beam arrangement, pinhole layout and beam paths, clear aperture budget, ray trace models, alignment constraints, lens designs, wavefront performance, and pupil aberrations are discussed. For the transport mirror system the layout, alignment controls and clear aperture budget are describe

English, R E; Korniski, R J; Miller, J L; Rodgers, J M

1998-06-26T23:59:59.000Z

106

SPARK! 2012 | ornl.gov  

NLE Websites -- All DOE Office Websites (Extended Search)

SPARK 2012 Technology Forum Dec 04 2012 08:00 AM - 05:00 PM Oak Ridge National Laboratory and the Technology 2020 Center for Entrepreneurial Growth hosted the third annual SPARK...

107

Maintenance FUSION IGNITION RESEARCH EXPERIMENT  

E-Print Network (OSTI)

to refine the system details, interfaces and the requirements for remote handling. Table 1. FIRE RadialInsulation Enclosure Remote Maintenance Module FUSION IGNITION RESEARCH EXPERIMENT SYSTEM objectives and subsystem requirements in an arrangement that allows remote maintenance of in

108

Ignition of Isomers of Pentane: An Experimental and Kinetic Modeling Study  

DOE Green Energy (OSTI)

Hydrocarbon ignition is an important element in many practical combustion systems, including internal combustion engines, detonations, pulse combustors, and flame initiation. The rapid compression machine (RCM) is used frequently to study the kinetics of hydrocarbon autoignition [e.g., 1-7], since the reactive gas temperatures and time histories are similar to those seen in automotive engines during Diesel ignition and end gas autoignition leading to engine knock in spark-ignition engines. The RCM provides a rich environment for study of the theory of hydrocarbon oxidation, including degenerate chain branching, alkylperoxy radical isomerization and effects of thermal feedback [8]. The literature of hydrocarbon oxidation studies in the RCM has been summarized recently [9,10], and many classes of fuels have been studied. Detailed kinetic modeling is another tool available to study hydrocarbon oxidation in the RCM [4,11]. The aim of the present work is to determine experimentally the influence of variations in fuel molecular structure on autoignition, and to use a kinetic model to understand the reasons for those variations. This study is unique in that while other studies have addressed variations in pressure and equivalence ratio on ignition [11], this work addresses effects of variations in fuel molecular structure for all of the isomers of a single fuel formula, pentane, in a RCM. The three isomers of pentane possess many of the structural elements that determine such autoignition characteristics as octane number and variability in cool flame production, so this study will benefit our efforts to describe these effects.

Ribaucour, M; Minetti, R; Sochet, L R; Curran, H J; Pitz, W J; Westbrook, C K

2000-01-11T23:59:59.000Z

109

Ignition and Inertial Confinement Fusion at The National Ignition Facility  

SciTech Connect

The National Ignition Facility (NIF), the world's largest and most powerful laser system for inertial confinement fusion (ICF) and for studying high-energy-density (HED) science, is now operational at Lawrence Livermore National Laboratory (LLNL). The NIF is now conducting experiments to commission the laser drive, the hohlraum and the capsule and to develop the infrastructure needed to begin the first ignition experiments in FY 2010. Demonstration of ignition and thermonuclear burn in the laboratory is a major NIF goal. NIF will achieve this by concentrating the energy from the 192 beams into a mm{sup 3}-sized target and igniting a deuterium-tritium mix, liberating more energy than is required to initiate the fusion reaction. NIF's ignition program is a national effort managed via the National Ignition Campaign (NIC). The NIC has two major goals: execution of DT ignition experiments starting in FY2010 with the goal of demonstrating ignition and a reliable, repeatable ignition platform by the conclusion of the NIC at the end of FY2012. The NIC will also develop the infrastructure and the processes required to operate NIF as a national user facility. The achievement of ignition at NIF will demonstrate the scientific feasibility of ICF and focus worldwide attention on laser fusion as a viable energy option. A laser fusion-based energy concept that builds on NIF, known as LIFE (Laser Inertial Fusion Energy), is currently under development. LIFE is inherently safe and can provide a global carbon-free energy generation solution in the 21st century. This paper describes recent progress on NIF, NIC, and the LIFE concept.

Moses, E

2009-10-01T23:59:59.000Z

110

Preparing for Ignition Experiments on the National Ignition Facility  

SciTech Connect

The National Ignition Facility (NIF) is a 192-beam Nd-glass laser facility presently under construction at Lawrence Livermore National Laboratory (LLNL) for performing ignition experiments for inertial confinement fusion (ICF) and experiments studying high energy density (HED) science. NIF will produce 1.8 MJ, 500 TW of ultraviolet light ({lambda} = 351 nm) making it the world's largest and most powerful laser system. NIF will be the world's preeminent facility for the study of matter at extreme temperatures and densities for producing and developing ICF. The ignition studies will be an essential step in developing inertial fusion energy (IFE). the NIF Project is over 93% complete and scheduled for completion in 2009. Experiments using one beam have demonstrated that NIF can meet all of its performance goals. A detailed plan called the National Ignition Campaign (NIC) has been developed to begin ignition experiments in 2010. The plan includes the target physics and the equipment such as diagnostics, cryogenic target manipulator and user optics required for the ignition experiment. Target designs have been developed that calculate to ignite at energy as low as 1 MJ. Plans are under way to make NIF a national user facility for experiments on HED physics and nuclear science, including experiments relevant to the development of IFE.

Moses, E; Meier, W

2007-08-28T23:59:59.000Z

111

Special Feature: Energy - The Spark that Ignited DOE Supercomputing  

NLE Websites -- All DOE Office Websites (Extended Search)

of civilization. Every time you add firewood to a dying fire, you are converting biomass (wood) into energy (heat) through a process called direct combustion. For thousands of...

112

The Effects of Fuel Characteristics on Stoichiometric Spark-Assisted HCCI  

SciTech Connect

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.

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

2012-01-01T23:59:59.000Z

113

SPARK! 2013 | ornl.gov  

NLE Websites -- All DOE Office Websites (Extended Search)

3 Technology Forum 3 Technology Forum Nov 19 2013 01:00 PM - 06:30 PM Market focused presentations on Oak Ridge National Lab's most promising inventions. JICS Auditorium, Building 5100, Oak Ridge National Laboratory Oak Ridge, Tennessee CONTACT : Email: Teresa Snow Phone:865.574.0553 Add to Calendar SHARE Real-time automobile weld quality inspection system Spark! Advanced materials for tomorrow's products High-performance plastics from renewable sources Cast alumina forming austenitic stainless steel for high temperature and corrosive environments Optically transparent, durable superhydrophobic thin film coatings Low cost fermentation system for production of high value materials Energy storage and electric vehicle technologies '' Low-cost graphite from recycles tires for lithium ion batteries

114

The Effects of Fuel Characteristics on Stoichiometric Spark-Assisted HCCI  

DOE Green Energy (OSTI)

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.

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

2011-01-01T23:59:59.000Z

115

Spark gap switch with spiral gas flow  

DOE Patents (OSTI)

A spark gap switch having a contaminate removal system using an injected gas. An annular plate concentric with an electrode of the switch defines flow paths for the injected gas which form a strong spiral flow of the gas in the housing which is effective to remove contaminates from the switch surfaces. The gas along with the contaminates is exhausted from the housing through one of the ends of the switch.

Brucker, J.P.

1988-03-23T23:59:59.000Z

116

The influence of the external circuit on arc-discharge of a spark-gap: Its application to a pulsed gas laser  

SciTech Connect

An investigation of the influence of the driving circuit on the arc-discharge of a spark-gap takes place in this work. The two most common types of circuits used in pulsed gas lasers have been studied for all possible combinations of capacitance allocation. In these circuits the spark-gap is used as ignition system and participates in the electric circuit through its resistance and inductance. This consideration shows that capacitances act as charge containers and feed the arc-discharge in the spark-gap independently of their positions in the circuit. Their values influence the total charge contained in the arc-discharge and this, in its turn, influences the discharge resistance. On the other hand, total charge flows through the discharge at a rate determined by the coupling of the circuit loops, namely, by the circuit type. Thus, circuit type influences the drift velocity and this, in its turn, influences the channel radius, which determines the discharge inductance.

Persephonis, P.; Giannetas, V.; Georgiades, C.; Parthenios, J.; Ioannou, A. [Univ. of Patras (Greece). Dept. of Physics

1995-03-01T23:59:59.000Z

117

Laser preheat enhanced ignition  

DOE Patents (OSTI)

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.

Early, James W. (Los Alamos, NM)

1999-01-01T23:59:59.000Z

118

The Design and Implementation of the Integrated Timing System to be Used in the National Ignition Facility  

DOE Green Energy (OSTI)

The National Ignition Facility, or NIF, currently under construction at the Lawrence Livermore National Laboratory will contain the world's most powerful laser. By the year 2003 the NIF laser will be a research tool allowing scientists a glimpse into plasma interactions that are equivalent to those found in the center of the sun. Every eight hours the NIF will generate 1.8 MJ of 351-nm light carried by 192 pulsed laser beams and focus it onto a pea-sized target. This will result in a fusion reaction between two isotopes of hydrogen, creating for a few hundred picoseconds stellar conditions. Synchronizing the beams and diagnosing the fusion reaction requires generation and delivery of over 1000 precisely timed triggers to a multitude of systems. The NIF Integrated Timing System (ITS) was developed to provide reliable, accurately timed triggers that allow each client system to operate independently during periods of shot preparation and maintenance, yet be coordinated to a few tens of picoseconds during the experiment. The ITS applies technologies developed for fiber communications and Two-Way Time Transfer, and integrates them by way of a computer communications network to achieve distributed control, dynamically configurable coordination and independent among timing channels, and integrated self-diagnostics.

Coutts, G.W.; Wiedwald, J.D.; Sewall, N.; Lagin, L.

1999-12-07T23:59:59.000Z

119

IGNITION AND FRONTIER SCIENCE ON THE NATIONAL IGNITION FACILITY  

Science Conference Proceedings (OSTI)

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.

Moses, E

2009-06-22T23:59:59.000Z

120

Resistance of a water spark.  

Science Conference Proceedings (OSTI)

The later time phase of electrical breakdown in water is investigated for the purpose of improving understanding of the discharge characteristics. One dimensional simulations in addition to a zero dimensional lumped model are used to study the spark discharge. The goal is to provide better electrical models for water switches used in the pulse compression section of pulsed power systems. It is found that temperatures in the discharge channel under representative drive conditions, and assuming small initial radii from earlier phases of development, reach levels that are as much as an order of magnitude larger than those used to model discharges in atmospheric gases. This increased temperature coupled with a more rapidly rising conductivity with temperature than in air result in a decreased resistance characteristic compared to preceding models. A simple modification is proposed for the existing model to enable the approximate calculation of channel temperature and incorporate the resulting conductivity increase into the electrical circuit for the discharge channel. Comparisons are made between the theoretical predictions and recent experiments at Sandia. Although present and past experiments indicated that preceding late time channel models overestimated channel resistance, the calculations in this report seem to underestimate the resistance relative to recent experiments. Some possible reasons for this discrepancy are discussed.

Warne, Larry Kevin; Jorgenson, Roy Eberhardt; Lehr, Jane Marie

2005-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "ignition system spark" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Spark gap with low breakdown voltage jitter  

SciTech Connect

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.

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

1996-01-01T23:59:59.000Z

122

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

SciTech Connect

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.

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

2004-04-30T23:59:59.000Z

123

Target diagnostic control system implementation for the National Ignition Facility (invited)  

Science Conference Proceedings (OSTI)

The extreme physics of targets shocked by NIF's 192-beam laser is observed by a diverse suite of diagnostics. Many diagnostics are being developed by collaborators at other sites, but ad hoc controls could lead to unreliable and costly operations. A diagnostic control system (DCS) framework for both hardware and software facilitates development and eases integration. Each complex diagnostic typically uses an ensemble of electronic instruments attached to sensors, digitizers, cameras, and other devices. In the DCS architecture each instrument is interfaced to a low-cost WINDOWS XP processor and JAVA application. Each instrument is aggregated with others as needed in the supervisory system to form an integrated diagnostic. The JAVA framework provides data management, control services, and operator graphical user interface generation. DCS instruments are reusable by replication with reconfiguration for specific diagnostics in extensible markup language. Advantages include minimal application code, easy testing, and high reliability. Collaborators save costs by assembling diagnostics with existing DCS instruments. This talk discusses target diagnostic instrumentation used on NIF and presents the DCS architecture and framework.

Shelton, R. T.; Kamperschroer, J. H.; Lagin, L. J.; Nelson, J. R.; O'Brien, D. W. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

2010-10-15T23:59:59.000Z

124

GREET InclGREET Includes More Thanudes More Than 50 Long-Term Veh50 Long-Term Vehicle/Fuel Systemsicle/Fuel Systems  

E-Print Network (OSTI)

Flared Gas Conv. & Reform. Gasoline Conv. & Reform. Gasoline Conv. & Reform. Gasoline Conv. & Reform-ignition enginesDirect-injection, spark-ignition engines · Direct-injection, compression ignition enginesDirect-injection, compression ignition engines · Grid-independent hybrid electric vehiclesGrid-independent hybrid electric

Argonne National Laboratory

125

Predicting Ignition Delay for Gas Turbine Fuel Flexibility  

NLE Websites -- All DOE Office Websites (Extended Search)

Predicting Ignition Delay for Gas Turbine Fuel Flexibility 15 m * Low emission combustion systems have been carefully optimized for natural gas * Future fuel diversity (including...

126

Ignition Rate Measurement of Laser-Ignited Coals  

SciTech Connect

We established a novel experiment to study the ignition of pulverized coals under conditions relevant to utility boilers. Specifically, we determined the ignition mechanism of pulverized-coal particles under various conditions of particle size, coal type, and freestream oxygen concentration. We also measured the ignition rate constant of a Pittsburgh #8 high-volatile bituminous coal by direct measurement of the particle temperature at ignition, and incorporating this measurement into a mathematical model for the ignition process. The model, called Distributed Activation Energy Model of Ignition, was developed previously by our group to interpret conventional drop-tube ignition experiments, and was modified to accommodate the present study.

John C. Chen; Vinayak Kabadi

1997-10-31T23:59:59.000Z

127

Chemical kinetic modelling of hydrocarbon ignition  

DOE Green Energy (OSTI)

Chemical kinetic modeling of hydrocarbon ignition is discussed with reference to a range of experimental configurations, including shock tubes, detonations, pulse combustors, static reactors, stirred reactors and internal combustion engines. Important conditions of temperature, pressure or other factors are examined to determine the main chemical reaction sequences responsible for chain branching and ignition, and kinetic factors which can alter the rate of ignition are identified. Hydrocarbon ignition usually involves complex interactions between physical and chemical factors, and it therefore is a suitable and often productive subject for computer simulations. In most of the studies to be discussed below, the focus of the attention is placed on the chemical features of the system. The other physical parts of each application are generally included in the form of initial or boundary conditions to the chemical kinetic parts of the problem, as appropriate for each type of application being addressed.

Westbrook, C.K.; Pitz, W.J.; Curran, H.J.; Gaffuri, P.; Marinov, N.M.

1995-08-25T23:59:59.000Z

128

Frostbite Theater - Static Electricity Experiments - Big Sparks...  

NLE Websites -- All DOE Office Websites (Extended Search)

Van de Graaff Confetti Explosion Previous Video (Van de Graaff Confetti Explosion) Frostbite Theater Main Index Next Video (Polar Molecules) Polar Molecules Big Sparks, Little...

129

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

Open Energy Info (EERE)

| Sign Up Search Facebook icon Twitter icon CHEVROLET | ELECTRIC | GREEN | SPARK EV | TECHNOLOGY. INNOVATION & SOLUTIONS | GREENER VEHICLES Home There are currently no...

130

Progress Toward Ignition on the National Ignition Facility  

SciTech Connect

The principal approach to ignition on the National Ignition Facility (NIF) is indirect drive. A schematic of an ignition target is shown in Figure 1. The laser beams are focused through laser entrance holes at each end of a high-Z cylindrical case, or hohlraum. The lasers irradiate the hohlraum walls producing x-rays that ablate and compress the fuel capsule in the center of the hohlraum. The hohlraum is made of Au, U, or other high-Z material. For ignition targets, the hohlraum is {approx}0.5 cm diameter by {approx}1 cm in length. The hohlraum absorbs the incident laser energy producing x-rays for symmetrically imploding the capsule. The fuel capsule is a {approx}2-mm-diameter spherical shell of CH, Be, or C filled with DT fuel. The DT fuel is in the form of a cryogenic layer on the inside of the capsule. X-rays ablate the outside of the capsule, producing a spherical implosion. The imploding shell stagnates in the center, igniting the DT fuel. NIC has overseen installation of all of the hardware for performing ignition experiments, including commissioning of approximately 50 diagnostic systems in NIF. The diagnostics measure scattered optical light, x-rays from the hohlraum over the energy range from 100 eV to 500 keV, and x-rays, neutrons, and charged particles from the implosion. An example of a diagnostic is the Magnetic Recoil Spectrometer (MRS) built by a collaboration of scientists from MIT, UR-LLE, and LLNL shown in Figure 2. MRS measures the neutron spectrum from the implosion, providing information on the neutron yield and areal density that are metrics of the quality of the implosion. Experiments on NIF extend ICF research to unexplored regimes in target physics. NIF can produce more than 50 times the laser energy and more than 20 times the power of any previous ICF facility. Ignition scale hohlraum targets are three to four times larger than targets used at smaller facilities, and the ignition drive pulses are two to five times longer. The larger targets and longer pulse lengths produce unique plasma conditions for laser-plasma instabilities that could reduce hohlraum coupling efficiency. Initial experiments have demonstrated efficient coupling of laser energy to x-rays. X-ray drive greater than 300 eV has been measured in gas-filled ignition hohlraum and shows the expected scaling with laser energy and hohlraum scale size. Experiments are now optimizing capsule implosions for ignition. Ignition conditions require assembling the fuel with sufficient density and temperature for thermonuclear burn. X-rays ablate the outside of the capsule, accelerating and spherically compressing the capsule for assembling the fuel. The implosion stagnates, heating the central core and producing a hot spot that ignites and burns the surrounding fuel. The four main characteristics of the implosion are shell velocity, central hot spot shape, fuel adiabat, and mix. Experiments studying these four characteristics of implosions are used to optimize the implosion. Integrated experiments using cryogenic fuel layer experiments demonstrate the quality of the implosion as the optimization experiments progress. The final compressed fuel conditions are diagnosed by measuring the x-ray emission from the hot core and the neutrons and charged particles produced in the fusion reactions. Metrics of the quality of the implosion are the neutron yield and the shell areal density, as well as the size and shape of the core. The yield depends on the amount of fuel in the hot core and its temperature and is a gauge of the energy coupling to the fuel. The areal density, the density of the fuel times its thickness, diagnoses the fuel assembly, which is measured using the fraction of neutrons that are down scattered passing through the dense shell. The yield and fraction of down scattered neutrons, or shell rho-r, from the cryogenic layered implosions are shown in Figure 3. The different sets of data represent results after a series of implosion optimization experiments. Both yield and areal density show significant increases as a result of the optimiza

Kauffman, R L

2011-10-17T23:59:59.000Z

131

Spark Green Energy Pvt Ltd | Open Energy Information  

Open Energy Info (EERE)

Page Edit with form History Facebook icon Twitter icon Spark Green Energy Pvt Ltd Jump to: navigation, search Name Spark Green Energy Pvt Ltd. Place Mumbai, Maharashtra, India...

132

The Absence of Plasma in "Spark Plasma Sintering"  

E-Print Network (OSTI)

investigations on the spark plasma sintering/synthesisinvestigations on the spark plasma sintering/synthesisLichtenberg, Principles of Plasma Discharges and Materials

Hulbert, Dustin M.

2008-01-01T23:59:59.000Z

133

Changes related to "Blue Spark Technologies formerly Thin Battery...  

Open Energy Info (EERE)

icon Twitter icon Changes related to "Blue Spark Technologies formerly Thin Battery Technologies Inc" Blue Spark Technologies formerly Thin Battery Technologies Inc...

134

Pages that link to "Blue Spark Technologies formerly Thin Battery...  

Open Energy Info (EERE)

icon Twitter icon Pages that link to "Blue Spark Technologies formerly Thin Battery Technologies Inc" Blue Spark Technologies formerly Thin Battery Technologies Inc...

135

Alternative Fuels Data Center: Partnerships Spark Biodiesel Success for  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

Partnerships Spark Partnerships Spark Biodiesel Success for Essential Baking Company to someone by E-mail Share Alternative Fuels Data Center: Partnerships Spark Biodiesel Success for Essential Baking Company on Facebook Tweet about Alternative Fuels Data Center: Partnerships Spark Biodiesel Success for Essential Baking Company on Twitter Bookmark Alternative Fuels Data Center: Partnerships Spark Biodiesel Success for Essential Baking Company on Google Bookmark Alternative Fuels Data Center: Partnerships Spark Biodiesel Success for Essential Baking Company on Delicious Rank Alternative Fuels Data Center: Partnerships Spark Biodiesel Success for Essential Baking Company on Digg Find More places to share Alternative Fuels Data Center: Partnerships Spark Biodiesel Success for Essential Baking Company on

136

Gas mixtures for spark gap closing switches  

DOE Patents (OSTI)

Gas mixtures for use in spark gap closing switches comprised of fluorocarbons and low molecular weight, inert buffer gases. To this can be added a third gas having a low ionization potential relative to the buffer gas. The gas mixtures presented possess properties that optimized the efficiency spark gap closing switches. 6 figs.

Christophorou, L.G.; McCorkle, D.L.; Hunter, S.R.

1987-02-20T23:59:59.000Z

137

Valuation of a Spark Spread:  

E-Print Network (OSTI)

analysis and data in this paper was prepared for a consulting client and we are grateful that they have allowed us to adapt our report in the form of this academic paper. We have modified the plant-specific results in Section 8 to protect the proprietary data and property of our client. 1 1 Executive Summary This paper analyzes a power plant in Alberta, Canada, that is powered by two General Electric LM6000 gas turbines combined with a steam generator that allows combined cycle operations. The LM6000 is derived from a GE engine used on Boeing 767 and 747 airplanes, and is adapted for natural gas by General Electric. This power plant is popular in various power jurisdictions around the world as a turnkey power plant that can offer peaking capacity, and some baseload power delivery. We consider 4 operating modes for the plant: cold metal (off), 15 MW idle in combined cycle, full simple-cycle power (95 MW) and combined cycle full power (120 MW). It is common to refer to such a plant as generating a spark spread: converting natural gas to electricity by burning. A spark spread has two correlated stochastic variables: electricity price and natural gas price. To lower the dimensionality of the problem, we

An Lm Power Plant; Mark Cassano; Gordon Sick

2009-01-01T23:59:59.000Z

138

The National Ignition Facility and the Ignition Campaign  

E-Print Network (OSTI)

(atm-s) Indirect drive on the NIF is within a factor of 2-3 of the conditions required for ignition Callahan -- AAAS, February 14-18, 2013 82013-047661s2.ppt NIF Ignition #12;2013-047661s2.ppt Callahan -- AAAS and initiated operation of NIF as the world's premier HED science facility Story of NIF and Ignition 102013

139

Interested in discussing the commercialization of the SPARK ...  

Interested in discussing the commercialization of the SPARK technologies? Please complete: Your Name _____

140

Target Visualization at the National Ignition Facility  

SciTech Connect

As the National Ignition Facility continues its campaign to achieve ignition, new methods and tools will be required to measure the quality of the targets used to achieve this goal. Techniques have been developed to measure target surface features using a phase-shifting diffraction interferometer and Leica Microsystems confocal microscope. Using these techniques we are able to produce a detailed view of the shell surface, which in turn allows us to refine target manufacturing and cleaning processes. However, the volume of data produced limits the methods by which this data can be effectively viewed by a user. This paper introduces an image-based visualization system for data exploration of target shells at the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory. It aims to combine multiple image sets into a single visualization to provide a method of navigating the data in ways that are not possible with existing tools.

Potter, D

2011-11-21T23:59:59.000Z

Note: This page contains sample records for the topic "ignition system spark" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Spark Energy, LP | Open Energy Information  

Open Energy Info (EERE)

(Redirected from Spark Energy) (Redirected from Spark Energy) Jump to: navigation, search Name Spark Energy, LP Place Texas Utility Id 17710 Utility Location Yes Ownership R NERC Location TRE Activity Retail Marketing Yes References EIA Form EIA-861 Final Data File for 2010 - File1_a[1] LinkedIn Connections CrunchBase Profile No CrunchBase profile. Create one now! This article is a stub. You can help OpenEI by expanding it. Utility Rate Schedules Grid-background.png No rate schedules available. Average Rates Residential: $0.1460/kWh Commercial: $0.1210/kWh References ↑ "EIA Form EIA-861 Final Data File for 2010 - File1_a" Retrieved from "http://en.openei.org/w/index.php?title=Spark_Energy,_LP&oldid=411595" Categories: EIA Utility Companies and Aliases Utility Companies

142

ArcSafe® with Pulsed Arrested Spark Discharge  

NLE Websites -- All DOE Office Websites (Extended Search)

ArcSafe® ArcSafe® with Pulsed Arrested Spark Discharge  2007 R&D 100 Award Entry Form ArcSafe® with Pulsed Arrested Spark Discharge  Joint Submitters Submitting Organization Sandia National Laboratories PO Box 5800, MS 1181 Albuquerque, NM 87185-1181 USA Larry Schneider Phone: (505) 845-7135 Fax: (505) 845-7685 Email: lxschne@sandia.gov AFFIRMATION: I affirm that all information submitted as a part of, or supplemental to, this entry is a fair and accurate represen- tation of this product. (Signature)______________________________________ Astronics-Advanced Electronic Systems, Inc. 9845 Willows Rd NE City: Redmond State: WA Zip/Postal: 98052-2540 USA Contact Name: Michael Ballas, Program Manager Phone: (425) 895-4304 Fax: (425)702.4930 Email: michael.ballas@astronics.com

143

UCRL-PRES-225531 National ignition facility  

E-Print Network (OSTI)

Title Page UCRL-PRES-225531 #12;National ignition facility #12;NIF is 705,000 #12;NIF laser system #12;NIF us 885 #12;NIF-0506-11956 Laser bay 2 #12;Switchyard 2 #12;Target chamber in the air #12 experiments on NIF have demonstrated #12;21 1 MJ shaping results: Comparison of requested vs measured 3 pulse

144

Orchestrating shots for the national ignition racility  

Science Conference Proceedings (OSTI)

The National Ignition Facility (NIF), currently under construction at the Lawrence Livermore National Laboratory, is a stadium-sized facility containing a 192-beam, 1.8 Megajoule, 500-Terawatt, ultra-violet laser system together with a 10-meter diameter ... Keywords: Ada95, CORBA, XML, architecture, concurrency, data driven, framework, java, model-based, multi-threaded, state machine, workflow

David G. Mathisen; Robert W. Carey

2005-11-01T23:59:59.000Z

145

Spark-gap device for precise switching  

DOE Patents (OSTI)

An improved spark gap apparatus is provided for precise switching of high currents from charged capacitors, and for protecting circuitry and circuit components, such as an energy storage capacitor, from overvoltage surges. The invention includes a pair of niobium electrodes with a melting point greater than 2000/sup 0/C that forms the spark gap. The electrodes are supported by conductive caps spaced apart from one another by an insulating member all of which form a hermetically sealed chamber filled with an inert, ionizable gas, preferably pure xenon. The spark gap device includes a quantity of solid radioactive stabilizer, carbon-14, placed within the hermetically sealed chamber adjacent to the spark gap. Methods for fabricating the device and its components are described. It is claimed that use of the Nb electrodes forestalls electrode erosion even under severe voltage and discharge conditions, that, by employing pure Xe gas, and solid carbon-14 radiation stabilizer, it is unnecessary to employ radioactive gases or chemically plated radioactive sources to promote ionization, and that, by selection of a suitable spark gap, a spark gap device is obtained which is capable of switching at 1700 V +- 10% for input voltage rates up to 570 V/ms and allowing peak discharge currents up to 3000 A from a 0.3 microfarad energy storage capacitor for more than 1000 operations. (LCL)

Boettcher, G.E.

1982-01-28T23:59:59.000Z

146

The National Ignition Facility (NIF) and the National Ignition Campaign (NIC)  

SciTech Connect

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). NIF construction was certified by the Department of Energy as complete on March 27, 2009. NIF, a 192-beam Nd:glass laser facility, will ultimately produce 1.8-MJ, 500-TW of 351-nm third-harmonic, ultraviolet light. On March 10, 2009, 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 broader frontier scientific exploration. NIF experiments in support of indirect-drive ignition began in August 2009. These first experiments represent the next phase of the National Ignition Campaign (NIC). The NIC is a 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 includes diagnostics, a 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, integrated into the facility, and 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. 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 is planned for summer 2009. This paper summarizes the design, performance, and status of NIF and plans for the NIF ignition experimental program. A brief summary of the overall NIF experimental program is also presented.

Moses, E

2009-09-17T23:59:59.000Z

147

Compact Ignition Tokamak Program: issues to be resolved by January  

SciTech Connect

This Compact Ignition Tokamak Program report addresses unresolved issues concerning: concept configuration; design space characterization; facility/device layouts; auxiliary system development; cost; R and D; and alternate sites. (JDB)

Flanagan, C.A.

1985-01-01T23:59:59.000Z

148

An interim report on the materials and selection criteria analysis for the Compact Ignition Tokamak Toroidal Field Coil Turn-to-Turn Insulation System  

Science Conference Proceedings (OSTI)

Design criteria for the Compact Ignition Tokamak, Toroidal-Field (TF) Coil, Turn-to-Turn Insulation System require an insulation sheet and bonding system that will survive cryogenic cycling in a radiation environment and maintain structural integrity during exposure to the significant compressive and shear loads associated with each operating cycle. For thermosetting resin systems, a complex interactive dependency exists between optimum peak value, in-service property performance capabilities of candidate generic materials; key handling and processing parameters required to achieve their optimum in-service property performance as an insulation system; and suitability of their handling and processing parameters as a function of design configuration and assembly methodology. This dependency is assessed in a weighted study matrix in which two principal programmatic approaches for the development of the TF Coil Subassembly Insulation System have been identified. From this matrix study, two viable approaches to the fabrication of the insulation sheet were identified: use of a press-formed sheet bonded in place with epoxy for mechanical bonding and tolerance take-up and formation of the insulation sheet by placement of dry cloth and subsequent vacuum pressure impregnation. Laboratory testing was conducted to screen a number of combinations of resins and hardeners on a generic basis. These combinations were chosen for their performance in similar applications. Specimens were tested to screen viscosity, thermal-shock tolerance, and cryogenic tolerance. Cryogenic shock and cryogenic temperature proved to be extremely lethal to many combinations of resin, hardener, and cure. Two combinations survived: a heavily flexibilized bisphenol A resin with a flexibilized amine hardener and a bisphenol A resin with cycloaliphatic amine hardener. 7 refs., 12 figs., 6 tabs.

Campbell, V.W.; Dooley, J.B.; Hubrig, J.G.; Janke, C.J.; McManamy, T.J.; Welch, D.E.

1990-01-01T23:59:59.000Z

149

X-ray Streak Camera Cathode Development and Timing Accuracy of the 4w UV Fiducial System at the National Ignition Facility  

SciTech Connect

The convergent ablator experiments at the National Ignition Facility (NIF) are designed to measure the peak velocity and remaining ablator mass of an indirectly driven imploding capsule. Such a measurement can be performed using an x-ray source to backlight the capsule and an x-ray streak camera to record the capsule as it implodes. The ultimate goal of this experiment is to achieve an accuracy of 2% in the velocity measurement, which translates to a {+-}2 ps temporal accuracy over any 300 ps interval for the streak camera. In order to achieve this, a 4-{omega} (263nm) temporal fiducial system has been implemented for the x-ray streak camera at NIF. Aluminum, Titanium, Gold and Silver photocathode materials have been tested. Aluminum showed the highest quantum efficiency, with five times more peak signal counts per fiducial pulse when compared to Gold. The fiducial pulse data was analyzed to determine the centroiding a statistical accuracy for incident laser pulse energies of 1 and 10 nJ, showing an accuracy of {+-}1.6 ps and {+-}0.7 ps respectively.

Opachich, Y P; Palmer, N; Homoelle, D; Hatch, B W; Bell, P; Bradley, D; Kalantar, D; Browning, D; Landen, O

2012-05-02T23:59:59.000Z

150

X-ray streak camera cathode development and timing accuracy of the 4{omega} ultraviolet fiducial system at the National Ignition Facility  

Science Conference Proceedings (OSTI)

The convergent ablator experiments at the National Ignition Facility (NIF) are designed to measure the peak velocity and remaining ablator mass of an indirectly driven imploding capsule. Such a measurement can be performed using an x-ray source to backlight the capsule and an x-ray streak camera to record the capsule as it implodes. The ultimate goal of this experiment is to achieve an accuracy of 2% in the velocity measurement, which translates to a {+-}2 ps temporal accuracy over any 300 ps interval for the streak camera. In order to achieve this, a 4{omega} (263 nm) temporal fiducial system has been implemented for the x-ray streak camera at NIF. Aluminum, titanium, gold, and silver photocathode materials have been tested. Aluminum showed the highest relative quantum efficiency, with five times more peak signal counts per fiducial pulse when compared to Gold. The fiducial pulse data were analyzed to determine the centroiding statistical accuracy for incident laser pulse energies of 1 and 10 nJ, showing an accuracy of {+-}1.6 ps and {+-}0.7 ps, respectively.

Opachich, Y. P.; Palmer, N.; Homoelle, D.; Hatch, B.; Bell, P.; Bradley, D.; Kalantar, D.; Browning, D.; Landen, O. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Zuegel, J. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States)

2012-10-15T23:59:59.000Z

151

Princeton Plasma Physics Lab - National Ignition Facility  

NLE Websites -- All DOE Office Websites (Extended Search)

national-ignition-facility National Ignition Facility en Summary of Assessment of Prospects for Inertial Fusion Energy http:www.pppl.govnode1361

152

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

Open Energy Info (EERE)

Spark Energy, LP (New York) Jump to: navigation, search Name Spark Energy, LP Place New York Utility Id 17710 References EIA Form EIA-861 Final Data File for 2010 -...

153

Labyrinth for an ignition distributor cap and rotor assembly with atmospheric purging action  

SciTech Connect

This patent describes an ignition distributor to work with spark plug electrodes, a rotor electrode, a coil electrode and a shaft for an internal combustion engine with cylinders, the ignition distributor comprising: a bowl shaped housing; a distributor cap comprising: a generally dome shape with a generally hollow interior and with a circular shaped bottom to mate with the bowl shaped housing; spark towers equal in number to the number of cylinders of the internal combustion engine, projecting up from the top of the dome shape and slotted to accept spark plug electrodes and allow them to protrude into the distributor cap interior for communication with the rotor electrode; a vent tower projecting up from the top of the dome shape and provided with a vent port through to the distributor cap interior to allow for the outward flow of the atmosphere inside the distributor cap and bowl shaped housing; a coil tower projecting up from the top of the dome shape and slotted to accept a coil electrode and allow it to protrude into the distributor cap interior for communication with the rotor electrode; an inner labyrinth of annular shape on the interior surface of the dome shape surround the coil electrode and protruding into the hollow interior of the dome shape; and an outer labyrinth of annular shape on the interior surface of the dome shape surrounding the inner labyrinth thereby forming an annular channel.

Kronberger, L.J.

1986-12-23T23:59:59.000Z

154

Activated Sintering, Spark Plasma Sintering and High Voltage ...  

Science Conference Proceedings (OSTI)

Mar 4, 2013 ... Novel Synthesis and Consolidation of Powder Materials : Activated Sintering, Spark Plasma Sintering and High Voltage Electric Discharge ...

155

Ti compositions consolidated by spark plasma sintering and high ...  

Science Conference Proceedings (OSTI)

After electrical discharge machining these composite powders were consolidated by spark plasma sintering and high voltage consolidation. Microhardness of ...

156

Latest Developments in Spark OES for Iron and Steel Industry  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, Materials Science & Technology 2009. Symposium, Inclusions and Clean Steels. Presentation Title, Latest Developments in Spark ...

157

Spark gap device for precise switching  

DOE Patents (OSTI)

A spark gap device for precise switching of an energy storage capacitor into an exploding bridge wire load is disclosed. Niobium electrodes having a melting point of 2,415 degrees centrigrade are spaced apart by an insulating cylinder to define a spark gap. The electrodes are supported by conductive end caps which, together with the insulating cylinder, form a hermetically sealed chamber filled with an inert, ionizable gas, such as pure xenon. A quantity of solid radioactive carbon-14 within the chamber adjacent the spark gap serves as a radiation stabilizer. The sides of the electrodes and the inner wall of the insulating cylinder are spaced apart a sufficient distance to prevent unwanted breakdown initiation. A conductive sleeve may envelop the outside of the insulating member from the midpoint of the spark gap to the cap adjacent the cathode. The outer metallic surfaces of the device may be coated with a hydrogen-impermeable coating to lengthen the shelf life and operating life of the device. The device breaks down at about 1,700 volts for input voltage rates up to 570 volts/millisecond and allows peak discharge currents of up to 3,000 amperes from a 0.3 microfarad energy storage capacitor for more than 1,000 operations.

Boettcher, Gordon E. (Albuquerque, NM)

1984-01-01T23:59:59.000Z

158

Spark gap device for precise switching  

DOE Patents (OSTI)

A spark gap device for precise switching of an energy storage capacitor into an exploding bridge wire load is disclosed. Niobium electrodes having a melting point of 2,415 degrees centigrade are spaced apart by an insulating cylinder to define a spark gap. The electrodes are supported by conductive end caps which, together with the insulating cylinder, form a hermetically sealed chamber filled with an inert, ionizable gas, such as pure xenon. A quantity of solid radioactive carbon-14 within the chamber adjacent the spark gap serves as a radiation stabilizer. The sides of the electrodes and the inner wall of the insulating cylinder are spaced apart a sufficient distance to prevent unwanted breakdown initiation. A conductive sleeve may envelop the outside of the insulating member from the midpoint of the spark gap to the cap adjacent the cathode. The outer metallic surfaces of the device may be coated with a hydrogen-impermeable coating to lengthen the shelf life and operating life of the device. The device breaks down at about 1,700 volts for input voltage rates up to 570 volts/millisecond and allows peak discharge currents of up to 3,000 amperes from a 0.3 microfarad energy storage capacitor for more than 1,000 operations. 3 figs.

Boettcher, G.E.

1984-10-02T23:59:59.000Z

159

Underwater Sparking at Stora Enso North America  

Science Conference Proceedings (OSTI)

This report describes the results of two sparker projects at Stora Enso North America (SENA) facilities. The first project evaluated the effect of sparking on the dewatering of sludge. The second project studied the effect of sparker treatment on birch extractives.

2006-06-15T23:59:59.000Z

160

MILESTONES IN SOIL CHEMISTRY Donald L. Sparks  

E-Print Network (OSTI)

MILESTONES IN SOIL CHEMISTRY Donald L. Sparks An array of pioneering research, dealing with various aspects of soil chemistry, has appeared in Soil Science for the past 90 years. In this review, two papers others that he published in Soil Science established the importance of variable or pH- dependent surface

Sparks, Donald L.

Note: This page contains sample records for the topic "ignition system spark" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Drilling research on the electrical detonation and subsequent cavitation in a liquid technique (spark drilling). Status report, July 1--December 31, 1976  

DOE Green Energy (OSTI)

The electrical characteristics of water during a rapid electrical discharge have been determined. These characteristics were used in predicting energy in the spark drilling arc and in designing a new-generation spark drill. The design of this drill system is described, along with the proposed schedule of its fabrication and use. Other activities accomplished during this report period are also discussed.

Not Available

1976-04-01T23:59:59.000Z

162

Ris-R-Report Development and Test of a new Concept for  

E-Print Network (OSTI)

is included in the gasifier system. · Experiments were conducted with two spark ignition gas engines, one

163

SPARK: A Framework for Multi-Scale Agent-Based Biomedical Modeling  

Science Conference Proceedings (OSTI)

Multi-scale modeling of complex biological systems remains a central challenge in the systems biology community. A method of dynamic knowledge representation known as agent-based modeling enables the study of higher level behavior emerging from discrete ... Keywords: Agent-Based, Computer Simulation, Framework, Models, SPARK

Alexey Solovyev; Maxim Mikheev; Leming Zhou; Joyeeta Dutta-Moscato; Cordelia Ziraldo; Gary An; Yoram Vodovotz; Qi Mi

2010-07-01T23:59:59.000Z

164

Predicting Ignition Delay for Gas Turbine Fuel Flexibility  

NLE Websites -- All DOE Office Websites (Extended Search)

Ignition Delay for Ignition Delay for Gas Turbine Fuel Flexibility 15 μm * Low emission combustion systems have been carefully optimized for natural gas * Future fuel diversity (including H2 containing fuels) may generate auto-ignition damage * Existing theories vary in predicting propensity for auto-ignition damage * Theory A vs Theory B shows factor of 100 difference-which is right? * UC Irvine improved and validated design tools for ignition delay allow designers to evaluate the risk for auto-ignition in advanced combustion systems with future fuels * Models are available to engine OEM's to shorten design cycle time and save $$ UC Irvine Scott Samuelsen / Vince McDonell #112 1000/T (1/K) 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 τ [O 2 ] 0.5 [F] 0.25 (sec(mol/cm 3 ) 0.75 ) 10 -10 10 -9 10 -8 10 -7 10 -6 10 -5

165

TOWARD A STANDARD IGNITION SOURCE  

E-Print Network (OSTI)

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

Volkingburg, David R. Van

2011-01-01T23:59:59.000Z

166

Particulate Emissions from a Pre-Emissions Control Era Spark-Ignition Vehicle: A Historical Benchmark  

DOE Green Energy (OSTI)

This study examined the particulate emissions from a pre-emissions control era vehicle operated on both leaded and unleaded fuels for the purpose of establishing a historical benchmark. A pre-control vehicle was located that had been rebuilt with factory original parts to approximate an as-new vehicle prior to 1968. The vehicle had less than 20,000 miles on the rebuilt engine and exhaust. The vehicle underwent repeated FTP-75 tests to determine its regulated emissions, including particulate mass. Additionally, measurements of the particulate size distribution were made, as well as particulate lead concentration. These tests were conducted first with UTG96 certification fuel, followed by UTG96 doped with tetraethyl lead to approximate 1968 levels. Results of these tests, including transmission electron micrographs of individual particles from both the leaded and unleaded case are presented. The FTP composite PM emissions from this vehicle averaged 40.5 mg/mile using unleaded fuel. The results from the leaded fuel tests showed that the FTP composite PM emissions increased to an average of 139.5 mg/mile. Analysis of the particulate size distribution for both cases demonstrated that the mass-based size distribution of particles for this vehicle is heavily skewed towards the nano-particle range. The leaded-fuel tests showed a significant increase in mass concentration at the <0.1 micron size compared with the unleaded-fuel test case. The leaded-fuel tests produced lead emissions of nearly 0.04 g/mi, more than a 4-order-of-magnitude difference compared with unleaded-fuel results. Analysis of the size-fractionated PM samples showed that the lead PM emissions tended to be distributed in the 0.25 micron and smaller size range.

John M.E. Storey; C. Scott Sluder; Douglas A. Blom; Erin Higinbotham

2000-06-19T23:59:59.000Z

167

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

E-Print Network (OSTI)

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 ...

Negrete, Justin E

2010-01-01T23:59:59.000Z

168

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

E-Print Network (OSTI)

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 ...

Kasseris, Emmanuel P

2011-01-01T23:59:59.000Z

169

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

E-Print Network (OSTI)

Cylinder Engine Study with Propane as a Fuel," SAE Paper No.Wall-Quenching of Laminar Propane Flames as a Function ofQuenching Distance of Propane-Air Flames in a Constant-

Ishikawa, Nobuhiko

2011-01-01T23:59:59.000Z

170

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

E-Print Network (OSTI)

(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. ...

Yilmaz, Ertan, 1970-

2003-01-01T23:59:59.000Z

171

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

E-Print Network (OSTI)

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. ...

Senzer, Eric B

2007-01-01T23:59:59.000Z

172

Conceptual Design - Polar Drive Ignition Campaign  

SciTech Connect

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.

Hansen, R

2012-04-05T23:59:59.000Z

173

Conceptual Design - Polar Drive Ignition Campaign  

SciTech Connect

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.

Hansen, R

2012-04-05T23:59:59.000Z

174

Exploring the Fast Ignition Approach to Fusion Energy  

DOE Green Energy (OSTI)

Probably the most famous equation in physics is Einstein's E=mc{sup 2}, which was contained within his fifth and final paper that was published in 1905. It is this relationship between energy ( E) and mass ( m) that the fusion process exploits to generate energy. When two isotopes of hydrogen (normally Deuterium and Tritium (DT)) fuse they form helium and a neutron. In this process some of the mass of the hydrogen is converted into energy. In the fast ignition approach to fusion a large driver (such as the NIF laser) is used to compress the DT fuel to extremely high densities and then is ''sparked'' by a high intensity, short-pulse laser. The short-pulse laser energy is converted to an electron beam, which then deposits its energy in the DT fuel. The energy of the electrons in this beam is so large that the electron's mass is increased according to Einstein theory of relativity. Understanding the transport of this relativistic electron beam is critical to the success of fast ignition and is the subject of this poster.

Town, R J; Chung, H; Cottrill, L A; Foord, M; Hatchett, S P; Key, M H; Langdon, A B; Lasinski, B F; Lund, S; Mackinnon, A J; McCandless, B C; Patel, P K; Sharp, W L; Snavely, R A; Still, C H; Tabak, M

2005-04-18T23:59:59.000Z

175

National Ignition Facility (NIF): Under Pressure: Ramp-Compression...  

NLE Websites -- All DOE Office Websites (Extended Search)

National Ignition Facility (NIF): Under Pressure: Ramp-Compression Smashes Record American Fusion News Category: National Ignition Facility Link: National Ignition Facility (NIF):...

176

Evaluation of unthrottled combustion system options for light duty applications with future syncrude derived fuels. Alternative Fuels Utilization Program  

DOE Green Energy (OSTI)

An experimental program examining the interaction between several fuel and light duty automotive engine combinations is detailed. Combustion systems addressed covered indirect and direct injection diesel and spark ignited stratified charge. Fuels primarily covered D2, naphtha and intermediate broadcut blends. Low ignition quality diesel fuels were also evaluated. The results indicate the baseline fuel tolerance of each combustion system and enable characteristics of the systems to be compared. Performance, gaseous and particulate emissions aspects were assessed. The data obtained assists in the selection of candidate combustion systems for potential future fuels. Performance and environmental penalties as appropriate are highlighted relative to the individual candidates. Areas of further work for increased understanding are also reviewed.

Needham, J. R.; Cooper, B. M.; Norris-Jones, S. R.

1982-12-01T23:59:59.000Z

177

HIGH VOLTAGE, HIGH CURRENT SPARK GAP SWITCH  

DOE Patents (OSTI)

A high voltage and current spark gap switch comprising two main electrodes insulatingly supported in opposed spaced relationship and a middle electrode supported medially between the main electrodes and symmetrically about the median line of the main electrodes is described. The middle electrode has a perforation aligned with the median line and an irradiation electrode insulatingly supported in the body of the middle electrode normal to the median line and protruding into the perforation. (AEC)

Dike, R.S.; Lier, D.W.; Schofield, A.E.; Tuck, J.L.

1962-04-17T23:59:59.000Z

178

Green Spark Ventures LLC | Open Energy Information  

Open Energy Info (EERE)

Spark Ventures LLC Spark Ventures LLC Jump to: navigation, search Name Green Spark Ventures, LLC Place Denver, Colorado Zip 80203 Sector Efficiency, Renewable Energy Product Denver-based venture capital fund prioritizing investing in start-up and early-stage companies in the Rocky Mountain region, operating in the area of renewable energy and energy efficiency. Coordinates 39.74001°, -104.992259° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":39.74001,"lon":-104.992259,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

179

Ignition Analysis of a Porous Energetic Material - II. Ignition at a Closed Heated End  

Science Conference Proceedings (OSTI)

A continuation of an ignition analysis for porous energetic materials subjected to a constant energy flux is presented. In the first part (I), the analysis was developed for the case of an open-end, semi-infinite material such that gas flow, generated by thermal expansion, flowed out of the porous solid, thereby removing energy from the system. In the present study, the case of a closed end is considered, and thus the thermally-induced gas flow is now directed into the solid. In these studies, an asymptotic perturbation analysis, based on the smallness of the gas-to-solid density ratio and the largeness of the activation energy, is utilized to describe the inert and transition stages leading to thermal runaway. In both cases it is found that the effects of porosity provide a leading-order reduction in the time to ignition relative to that for the nonporous problem, arising from the reduced amount of solid material that must be heated and the difference in thermal conductivities of the solid and gaseous phases. A correction to the leading-order ignition-delay time, however, is provided by the convective flow of gas through the solid, and the sign of this correction is shown to depend on the direction of the gas flow. Thus, gas flowing out of an open-end solid was previously shown to give a positive correction to the leading-order time to ignition. Here, however, it is demonstrated that when the flow of gas is directed into the porous solid, the relative transport effects associated with the gas flow serve to preheat the material, resulting in a negative correction and hence a decrease in the ignition-delay time.

S. B. Margolis; A. M. Telengator; F. A. Williams

1999-01-10T23:59:59.000Z

180

Ignition analysis of a porous energetic material. 2. Ignition at a closed heated end  

SciTech Connect

A continuation of an ignition analysis for porous energetic materials subjected to a constant energy flux is presented. In the first part, the analysis was developed for the case of an open-end, semi-infinite material such that gas flow, generated by thermal expansion, flowed out of the porous solid, thereby removing energy from the system. In the present study, the case of a closed end is considered, and thus the thermally-induced gas flow is now directed into the solid. In these studies, an asymptotic perturbation analysis, based on the smallness of the gas-to-solid density ratio and the largeness of the activation energy, is utilized to describe the inert and transition stages leading to thermal runaway. In both cases it is found that the effects of porosity provide a leading-order reduction in the time to ignition relative to that for the nonporous problem, arising from the reduced amount of solid material that must be heated and the difference in thermal conductivities of the solid and gaseous phases. A correction to the leading-order ignition-delay time, however, is provided by the convective flow of gas through the solid, and the sign of this correction is shown to depend on the direction of the gas flow. Thus, gas flowing out of an open-end solid was previously shown to give a positive correction to the leading-order time to ignition. Here, however, it is demonstrated that when the flow of gas is directed into the porous solid, the relative transport effects associated with the gas flow serve to preheat the material, resulting in a negative correction and hence a decrease in the ignition-delay time.

Alexander M. Telegentor; Stephen B. Margolis; Forman A. Williams

1998-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "ignition system spark" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

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

DOE Green Energy (OSTI)

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.

Flowers, D L

2002-06-07T23:59:59.000Z

182

A SPARK-GAP TRIGGER SYSTEM  

E-Print Network (OSTI)

Amplifier sWitch 30-kV condensers g~ p Coincidence circuita 30-kV O.012-! J.F condenser into the load. The In 9rder todischarged the high-voltage condenser into the load. In

Schrank, Glen E.

2010-01-01T23:59:59.000Z

183

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

SciTech Connect

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.

Moses, E

2006-11-27T23:59:59.000Z

184

Thermal Stability of Al 5356 Processed by Cryomilling and Spark ...  

Science Conference Proceedings (OSTI)

... Thermal Stability of Al 5356 Processed by Cryomilling and Spark Plasma Sintering ... Ordered Complexions: The Structure and Energy of Ni-Al2O3 Interfaces.

185

Sintering Studies of Ceramic-carbon Structures by Spark Plasma ...  

Science Conference Proceedings (OSTI)

Presentation Title, Sintering Studies of Ceramic-carbon Structures by Spark Plasma Sintering (SPS). Author(s), Miriam Miranda, Na Ni, Ben Milsom, Michael J .

186

Spark Plasma Sintering of Amorphous Coatings on Metallic Substrate  

Science Conference Proceedings (OSTI)

In the present work, we will discuss the results of deposition of amorphous coatings on metallic substrates using spark plasma sintering method. The influence of ...

187

The Role of Spark Plasma Sintering in Thermoelectric ...  

Science Conference Proceedings (OSTI)

Presentation Title, The Role of Spark Plasma Sintering in Thermoelectric Nanocomposites: Effect of Nanostructures on Lattice Thermal Conductivity. Author(s) ...

188

Spark Plasma Sintering of Ultra-Fine Grained and Nanocrystalline ...  

Science Conference Proceedings (OSTI)

In our work we focused on sintering of the nanocrystalline WC based hard metals using the spark plasma sintering method. Two types of materials i) WC-Co ...

189

Integrated Electro-Thermo-Mechanical Analysis of Spark Plasma ...  

Science Conference Proceedings (OSTI)

The modeling includes novel constitutive concepts of spark plasma sintering and the finite-element analysis with coupled electrical, thermal, and mechanical ...

190

Spark Plasma Sintering of Annular Zirconium Carbide Powder ...  

Science Conference Proceedings (OSTI)

Presentation Title, Spark Plasma Sintering of Annular Zirconium Carbide Powder Pellets:Processing and Simulation. Author(s), Xialu Wei, Wei Li, Eugene A.

191

Temperature Uniformization in Spark-plasma Sintering by Novel ...  

Science Conference Proceedings (OSTI)

Abstract Scope, The scalability of Spark-Plasma Sintering (SPS – a technology effectively utilized for consolidation of nano-particulate materials) is strongly ...

192

Ceramics Sintering and Shaping Using the Spark Plasma Sintering ...  

Science Conference Proceedings (OSTI)

This presentation will emphasize the consolidation of such powders using the Spark Plasma Sintering (SPS) method. The role played by the external electrical  ...

193

(SPS) and Free Pressureless (FPSPS) Spark-Plasma Sintering  

Science Conference Proceedings (OSTI)

The modeling results are compared to the experimentally obtained data on the spark plasma sintering of high strength temperature resistant powder-based ...

194

Fundamentals of Spark-Plasma Sintering: Applications to Net ...  

Science Conference Proceedings (OSTI)

Net-shaping capabilities of spark-plasma sintering are analyzed both theoretically and experimentally. Modeling and experimentation are conducted for ...

195

Fabrication of Metal Matrix Composites via Spark Plasma Sintering ...  

Science Conference Proceedings (OSTI)

Presentation Title, Fabrication of Metal Matrix Composites via Spark Plasma Sintering for Nuclear Energy Application. Author(s), Indrajit Charit, Jonathan A.

196

Spark Plasma Sintering of Next Generation Nuclear Materials  

Science Conference Proceedings (OSTI)

... Spark Plasma Sintering of Next Generation Nuclear Materials. Author(s), Daniel Osterberg, Jeff Perkins, Matt Luke, Brian Jaques, Michael F Hurley, Darryl Butt.

197

The National Ignition Facility and the Path to Fusion Energy  

SciTech Connect

The National Ignition Facility (NIF) is operational and conducting experiments at the Lawrence Livermore National Laboratory (LLNL). The NIF is the world's largest and most energetic laser experimental facility with 192 beams capable of delivering 1.8 megajoules of 500-terawatt ultraviolet laser energy, over 60 times more energy than any previous laser system. The NIF can create temperatures of more than 100 million degrees and pressures more than 100 billion times Earth's atmospheric pressure. These conditions, similar to those at the center of the sun, have never been created in the laboratory and will allow scientists to probe the physics of planetary interiors, supernovae, black holes, and other phenomena. The NIF's laser beams are designed to compress fusion targets to the conditions required for thermonuclear burn, liberating more energy than is required to initiate the fusion reactions. Experiments on the NIF are focusing on demonstrating fusion ignition and burn via inertial confinement fusion (ICF). The ignition program is conducted via the National Ignition Campaign (NIC) - a partnership among LLNL, Los Alamos National Laboratory, Sandia National Laboratories, University of Rochester Laboratory for Laser Energetics, and General Atomics. The NIC program has also established collaborations with the Atomic Weapons Establishment in the United Kingdom, Commissariat a Energie Atomique in France, Massachusetts Institute of Technology, Lawrence Berkeley National Laboratory, and many others. Ignition experiments have begun that form the basis of the overall NIF strategy for achieving ignition. Accomplishing this goal will demonstrate the feasibility of fusion as a source of limitless, clean energy for the future. This paper discusses the current status of the NIC, the experimental steps needed toward achieving ignition and the steps required to demonstrate and enable the delivery of fusion energy as a viable carbon-free energy source.

Moses, E

2011-07-26T23:59:59.000Z

198

Laser ablation based fuel ignition  

DOE Patents (OSTI)

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.

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

1998-06-23T23:59:59.000Z

199

June 11, 1999: National Ignition Facility  

Energy.gov (U.S. Department of Energy (DOE))

June 11, 1999Secretary Richardson dedicates the National Ignition Facility target chamber at DOE's Lawrence Livermore National Laboratory.

200

Advanced ignition options for laser ICF  

E-Print Network (OSTI)

University of Rochester and Princeton Plasma Physics Laboratory #12;FSC · With day-one hardware, the NIF can explore high-gain shock ignition - Polar Shock Ignition (uses half the NIF beams to drive the implosion: multi-FM or 2D-SSD (talk by J. Soures at this meeting) The NIF can explore advanced ignition options

Note: This page contains sample records for the topic "ignition system spark" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

An introduction to spark spreads - Today in Energy - U.S. Energy ...  

U.S. Energy Information Administration (EIA)

The spark spread is a common metric for estimating the profitability of natural gas-fired electric generators. The spark spread is the difference between the price ...

202

Data Analysis, Pre-Ignition Assessment, and Post-Ignition Modeling of the Large-Scale Annular Cookoff Tests  

SciTech Connect

In order to understand the implications that cookoff of plastic-bonded explosive-9501 could have on safety assessments, we analyzed the available data from the large-scale annular cookoff (LSAC) assembly series of experiments. In addition, we examined recent data regarding hypotheses about pre-ignition that may be relevant to post-ignition behavior. Based on the post-ignition data from Shot 6, which had the most complete set of data, we developed an approximate equation of state (EOS) for the gaseous products of deflagration. Implementation of this EOS into the multimaterial hydrodynamics computer program PAGOSA yielded good agreement with the inner-liner collapse sequence for Shot 6 and with other data, such as velocity interferometer system for any reflector and resistance wires. A metric to establish the degree of symmetry based on the concept of time of arrival to pin locations was used to compare numerical simulations with experimental data. Several simulations were performed to elucidate the mode of ignition in the LSAC and to determine the possible compression levels that the metal assembly could have been subjected to during post-ignition.

G. Terrones; F.J. Souto; R.F. Shea; M.W.Burkett; E.S. Idar

2005-09-30T23:59:59.000Z

203

Ignition feedback regenerative free electron laser (FEL) amplifier  

Science Conference Proceedings (OSTI)

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.

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

2001-01-01T23:59:59.000Z

204

Stockpile Stewardship and the National Ignition Facility  

SciTech Connect

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.

Moses, E

2012-01-04T23:59:59.000Z

205

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

SciTech Connect

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.

Moses, E

2011-03-25T23:59:59.000Z

206

The Ignition Physics Study Group  

Science Conference Proceedings (OSTI)

In the US magnetic fusion program there have been relatively few standing committees of experts, with the mandate to review a particular sub-area on a continuing basis. Generally, ad hoc committees of experts have been assembled to advise on a particular issue. There has been a lack of broad, systematic and continuing review and analysis, combining the wisdom of experts in the field, in support of decision making. The Ignition Physics Study Group (IPSG) provides one forum for the systematic discussion of fusion science, complementing the other exchanges of information, and providing a most important continuity in this critical area. In a similar manner to the European program, this continuity of discussion and the focus provided by a national effort, Compact Ignition Tokamak (CIT), and international effort, Engineering Test Reactor (ETR), are helping to lower those barriers which previously were an impediment to rational debate.

Sheffield, J.

1987-01-01T23:59:59.000Z

207

National Ignition Facility Target Chamber  

DOE Green Energy (OSTI)

On June 11, 1999 the Department of Energy dedicated the single largest piece of the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) in Livermore, California. The ten (10) meter diameter aluminum target high vacuum chamber will serve as the working end of the largest laser in the world. The output of 192 laser beams will converge at the precise center of the chamber. The laser beams will enter the chamber in two by two arrays to illuminate 10 millimeter long gold cylinders called hohlraums enclosing 2 millimeter capsule containing deuterium, tritium and isotopes of hydrogen. The two isotopes will fuse, thereby creating temperatures and pressures resembling those found only inside stars and in detonated nuclear weapons, but on a minute scale. The NIF Project will serve as an essential facility to insure safety and reliability of our nation's nuclear arsenal as well as demonstrating inertial fusion's contribution to creating electrical power. The paper will discuss the requirements that had to be addressed during the design, fabrication and testing of the target chamber. A team from Sandia National Laboratories (SNL) and LLNL with input from industry performed the configuration and basic design of the target chamber. The method of fabrication and construction of the aluminum target chamber was devised by Pitt-Des Moines, Inc. (PDM). PDM also participated in the design of the chamber in areas such as the Target Chamber Realignment and Adjustment System, which would allow realignment of the sphere laser beams in the event of earth settlement or movement from a seismic event. During the fabrication of the target chamber the sphericity tolerances had to be addressed for the individual plates. Procedures were developed for forming, edge preparation and welding of individual plates. Construction plans were developed to allow the field construction of the target chamber to occur parallel to other NIF construction activities. This was necessary to achieve the overall schedule. Plans had to be developed for the precise location and alignment of laser beam ports. Upon completion of the fabrication of the aluminum target chamber in a temporary structure the 130 ton sphere was moved from the temporary construction enclosure to its final location in the target building. Prior to the installation of a concrete shield and after completion of the welding of the chamber penetrations vacuum leak checking was performed to insure the vacuum integrity of target chamber. The entire spherical chamber external surface supports a 40 cm thick reinforced concrete shield after installation in the target building. The final task is a total survey of the laser ports and the contour machining of spacer plates so that laser devices attached to these ports meet the alignment criteria.

Wavrik, R W; Cox, J R; Fleming, P J

2000-10-05T23:59:59.000Z

208

Ignitability Measurements with the Cone Calorimeter*  

Science Conference Proceedings (OSTI)

... 22. WD Weatherford, Jr and DM Sheppard, Basic studies of the mechanism of ignition of cellulosic materials. Tenth Symp. (IntI) on Combustion, pp. ...

2008-08-25T23:59:59.000Z

209

Ignition and spread of electrical wire fires  

E-Print Network (OSTI)

pilot source, placed in the center of the wire sample to initiate ignition, which heats the wire through both convection (major) and radiation (

Huang, Xinyan

2012-01-01T23:59:59.000Z

210

Modelling piloted ignition of wood and plastics  

SciTech Connect

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.

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

211

Groundbreaking at National Ignition Facility | National Nuclear...  

National Nuclear Security Administration (NNSA)

NNSA Archive Federal Employment Apply for Our Jobs Our Jobs Working at NNSA Blog Home > About Us > Our History > NNSA Timeline > Groundbreaking at National Ignition Facility...

212

Densification of Ductile Ceramic Nanoparticles by Spark Plasma ...  

Science Conference Proceedings (OSTI)

The effect of the elasto-plastic character of the ceramic nanoparticles was investigated during the densification by spark plasma sintering of LiF, Y2O3 and YAG ...

213

Spark Plasma Sintering of SiC-SiO  

Science Conference Proceedings (OSTI)

Presentation Title, Spark Plasma Sintering of SiC-SiO2 Composites with CVD SiO2 Coated SiC Powder. Author(s), Zhenhua He, Hirokazu Katsui, Rong Tu, ...

214

Fuel Economy of the 2014 Chevrolet Spark EV  

NLE Websites -- All DOE Office Websites (Extended Search)

Spark EV Search for Other Vehicles View the Mobile Version of This Page Automatic (A1) Electricity Compare Side-by-Side All-Electric Vehicle EPA Fuel Economy Miles per Gallon...

215

Analysis of the National Ignition Facility Ignition Hohlraum Energetics Experiments  

SciTech Connect

A series of forty experiments on the National Ignition Facility (NIF) [E. I. Moses et al., Phys. Plasmas 16, 041006 (2009)] to study energy balance and implosion symmetry in reduced- and full-scale ignition hohlraums was shot at energies up to 1.3 MJ. This paper reports the findings of the analysis of the ensemble of experimental data obtained that has produced an improved model for simulating ignition hohlraums. Last year the first observation in a NIF hohlraum of energy transfer between cones of beams as a function of wavelength shift between those cones was reported [P. Michel, et al, Phys of Plasmas, 17, 056305, (2010)]. Detailed analysis of hohlraum wall emission as measured through the laser entrance hole (LEH) has allowed the amount of energy transferred versus wavelength shift to be quantified. The change in outer beam brightness is found to be quantitatively consistent with LASNEX [G. B. Zimmerman and W. L. Kruer, Comments Plasma Phys. Control. Fusion 2, 51 (1975)] simulations using the predicted energy transfer when possible saturation of the plasma wave mediating the transfer is included. The effect of the predicted energy transfer on implosion symmetry is also found to be in good agreement with gated x-ray framing camera images. Hohlraum energy balance, as measured by x-ray power escaping the LEH, is quantitatively consistent with revised estimates of backscatter and incident laser energy combined with a more rigorous non-local-thermodynamic-equilibrium atomic physics model with greater emissivity than the simpler average-atom model used in the original design of NIF targets.

Town, R J; Rosen, M D; Michel, P A; Divol, L; Moody, J D; Kyrala, G A; Schneider, M B; Kline, J L; Thomas, C A; Milovich, J L; Callahan, D A; Meezan, N B; Hinkel, D E; Williams, E A; Berger, R L; Edwards, M J; Suter, L J; Haan, S W; Lindl, J D; Dixit, S; Glenzer, S H; Landen, O L; Moses, E I; Scott, H A; Harte, J A; Zimmerman, G B

2010-11-22T23:59:59.000Z

216

Tank farm deflagration rates due to various ignition sources  

SciTech Connect

This supporting document evaluates potential ignition sources, documents calculated deflagration rates in flammable gas tanks from these ignition sources, and assesses the efficacy of controls to mitigate or prevent ignition.

Powers, T.B., Westinghouse Hanford

1996-08-29T23:59:59.000Z

217

Parametric Analysis of a Solar Desiccant Cooling System using...  

NLE Websites -- All DOE Office Websites (Extended Search)

Parametric Analysis of a Solar Desiccant Cooling System using the SimSPARK Environment Title Parametric Analysis of a Solar Desiccant Cooling System using the SimSPARK Environment...

218

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

SciTech Connect

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.

Bunting, Bruce G [ORNL

2006-01-01T23:59:59.000Z

219

Relativistic Laser Plasma Research for Fast Ignition Laser Fusion  

E-Print Network (OSTI)

Reviewed are the present status and future prospects of the laser fusion research at the ILE (Institute of Laser Engineering) Osaka. The Gekko XII and Peta Watt laser system have been operated for investigating the fast ignition, the relativistic laser plasma interactions and so on. In particular, the fast ignition experiments with cone shell target have been in progress as the UK and US-Japan collaboration programs. In the experiments, the imploded high density plasmas are heated by irradiating 500 J level peta watt laser pulse. The thermal neutron yield is found to increase by three orders of magnitude by injecting the peta watt laser into the cone shell target. Transport of relativistic high density electron is the critical issue as the basic physics for understanding the dense plasma heating process. By the theory, simulation and experiment, the collective phenomena in the interactions of intense relativistic electron current with dense plasmas has been investigated to find the formation of self organized flow as the result of filamentation (Weibel) instability. Through the present understanding, the new project, FIREX-I has started recently to prove the principle of the fast ignition scheme. Keywords: fast ignition, peta watt laser, relativistic electron, weibel instability

Mima Kunioki; Tanaka Kazuo. A; Kodama Ryosuke; Johzaki Tomohiro; Nagatomo Hideo; Shiraga Hiroyuki; Miyanaga Noriaki; Azechi Hiroshi; Nakai Mitsuo; Norimatsu Takayoshi; Nagai Keiji; Sunahara Atsushi; Nishihara Katsunobu; Taguchi Toshihiro; Sakagami Hitoshi; Sentoku Yasuhiko; Ruhl Hartmut

2003-01-01T23:59:59.000Z

220

Prediction of ignition of glass-metal mixture  

SciTech Connect

The integral fast reactor concept developed by Argonne National Laboratory includes on-site processing and recycling of discharged core and blanket fuel materials. The process will be demonstrated using the fuel cycle facility (FCF) located at ANL's Idaho facility. One of the processing steps is the casting of metal-fuel alloy slugs. Although alternate techniques are being developed, the current reference calls for casting the metal into quartz molds. During the slug demolding process, however, some of the fuel alloy remains attached to the quartz and becomes waste. Other finely divided particles of alloy from this operation also become mixed with the glass-fuel waste. This waste material is temporarily stored in cylindrical cans filled with argon gas to prevent oxidation and pyrophoric ignition. However, this mixture may come into contact with air as result of an accident and ignite. The ignition of the mixture depends significantly on the heat transfer characteristics of the waste can, which loses heat to the environment by natural convection and radiation. Heat is generated in the fuel by self-heating due both to its plutonium content and residual fission products and by heating due to oxidation. If the heat generation rate is higher than the heat loss rate, the system may experience a breakaway oxidation reaction, which is termed ignition.

Parlatan, Y. (Massachusetts Inst. of Technology, Cambridge (United States)); Charak, I. (Argonne National Lab., IL (United States))

1992-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ignition system spark" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Lean-Burn Stationary Natural Gas Reciprocating Engine Operation with a Prototype Miniature Diode Side Pumped Passively Q-switched Laser Spark Plug  

DOE Green Energy (OSTI)

To meet the ignition system needs of large bore lean burn stationary natural gas engines a laser diode side pumped passively Q-switched laser igniter was developed and used to ignite lean mixtures in a single cylinder research engine. The laser design was produced from previous work. The in-cylinder conditions and exhaust emissions produced by the miniaturized laser were compared to that produced by a laboratory scale commercial laser system used in prior engine testing. The miniaturized laser design as well as the combustion and emissions data for both laser systems was compared and discussed. It was determined that the two laser systems produced virtually identical combustion and emissions data.

McIntyre, D.L.; Woodruff, S.D.; McMillian, M.H.; Richardson, S.W.; Gautam, Mridul

2008-04-01T23:59:59.000Z

222

Ignitions in mixtures of coal dust, air, and methane from abrasive impacts of hard minerals with pneumatic pipeline steel. Report of investigations 1976  

SciTech Connect

Laboratory equipment which simulated abrasive impacts between steel and minerals as might occur during pneumatic transport of coal was used by the Bureau of Mines to characterize the potential explosion hazard due to such collisions in an atmosphere of fine coal dust-air-methane. A variety of coal mine rock materials, including sandstone, limestone, and pyrite-bearing limestone, were impacted with specimens of pipeline steel. Tests were conducted in atmospheres containing zero to 6.4 vol-pct methane mixed with zero to 300 mg/l coal dust. Coal dust-air alone was not ignited by abrasive impacts, but additions of as little as 1 vol-pct methane to coal dust-air resulted in ignitions. Steel impacting against sandstone caused ignitions in coal-air-methane mixtures with the probability for ignitions increasing with an increase in methane. Ignitions in coal-air-methane were found to be caused by a hot friction-induced smear on the impacted rock at the impact site rather than by sparks. High-speed photography was used to verify this observation.

Kelley, J.E.; Forkner, B.L.

1976-01-01T23:59:59.000Z

223

Target Diagnostics Supports NIF's Path to Ignition  

SciTech Connect

The physics requirements derived from the National Ignition Facility (NIF) experimental campaigns are leading to a wide variety of target diagnostics. Software development for the control and analysis of these diagnostics is included in the NIF Integrated Computer Control System, Diagnostic Control System and Data Visualization. These projects implement the configuration, controls, data analysis and visual representation of most of these diagnostics. To date, over 40 target diagnostics have been developed to support NIF experiments. In 2011 diagnostics were developed or enhanced to measure Ignition performance in a high neutron yield environment. Performance is optimized around four key variables: Adiabat (a) which is the strength and timing of four shocks delivered to the target, Velocity (V) of the imploding target, Mix (M) is the uniformity of the burn, and the Shape (S) of the imploding Deuterium Tritium (DT) hot spot. The diagnostics used to measure each of these parameters is shown in figure 1. Adiabat is measured using the Velocity Interferometer System for Any Reflector (VISAR) diagnostic consisting of three streak cameras. To provide for more accurate adiabat measurements the VISAR streak cameras were enhanced in FY11 with a ten comb fiducial signal controller to allow for post shot correction of the streak camera sweep non-linearity. Mix is measured by the Neutron Time of Flight (NTOF) and Radiochemical Analysis of Gaseous Samples (RAGS) diagnostics. To accommodate high neutron yield shots, NTOF diagnostic controls are being modified to use Mach Zehnder interferometer signals to allow the digitizers to be moved from near the target chamber to the neutron shielded diagnostic mezzanine. In December 2011 the first phase of RAGS diagnostic commissioning will be completed. This diagnostic will analyze the tracers that are added to NIF target capsules that undergo nuclear reactions during the shot. These gases are collected and purified for nuclear counting by the RAGS system. Three new instrument controllers were developed and commissioned to support this diagnostic. A residual-gas analyzer (RGA) instrument measures the gas content at various points in the system. The Digital Gamma Spectrometer instrument measures the radiological spectrum of the decaying gas isotopes. A final instrument controller was developed to interface to a PLC based Gas collection system. In order to support the implosion velocity measurements an additional Gated X-ray Detector (GXD) diagnostic was tested and commissioned. This third GXD views the target through a slit contained in its snout and allows the other GXD diagnostics to be used for measuring the shape on the same shot. In order to measure the implosion shape in a high neutron environment, Actide Readout In A Neutron Environment (ARIANE) and Neutron Imaging (NI) diagnostics were commissioned. The controls for ARIANE, a fixed port gated x-ray imager, contain a neutron shielded camera and micro channel plate pulser with its neutron sensitive electronics located in the diagnostic mezzanine. The NI diagnostic is composed of two Spectral Instruments SI-1000 cameras located 20M from the target and provides neutron images of the DT hot spot for high yield shots. The development and commissioning of these new or enhanced diagnostics in FY11 have provided meaningful insight that facilitates the optimization of the four key Ignition variables. In FY12 they will be adding three new diagnostics and enhancing four existing diagnostics in support of the continuing optimization series of campaigns.

Shelton, R

2011-12-07T23:59:59.000Z

224

Blue Spark Technologies formerly Thin Battery Technologies Inc | Open  

Open Energy Info (EERE)

Spark Technologies formerly Thin Battery Technologies Inc Spark Technologies formerly Thin Battery Technologies Inc Jump to: navigation, search Name Blue Spark Technologies (formerly Thin Battery Technologies Inc.) Place Westlake, Ohio Zip 44130 Sector Carbon Product Developer and licensor of carbon-zinc battery technology. Coordinates 32.980007°, -97.168831° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":32.980007,"lon":-97.168831,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

225

Solar Project to Spark Students' Studies, School's Savings | Department  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Solar Project to Spark Students' Studies, School's Savings Solar Project to Spark Students' Studies, School's Savings Solar Project to Spark Students' Studies, School's Savings April 14, 2010 - 3:26pm Addthis Joshua DeLung What does this project do? Even this small group of initial panels is expected to reduce carbon emissions by 39,631 pounds annually and cut the school's energy costs by a few percentage points. A solar installation on the roof of Drury High School in North Adams, Mass., and an integrated curriculum for students will be the result of $300,000 in Energy Efficiency and Conservation Block Grants, funded by the Recovery Act. North Adams and neighboring Clarksburg, which also sends students to the high school, pooled their $150,000 grants to contribute to the project. "One of the beauties about that building is we have a rough idea of what

226

Solar Project to Spark Students' Studies, School's Savings | Department  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Project to Spark Students' Studies, School's Savings Project to Spark Students' Studies, School's Savings Solar Project to Spark Students' Studies, School's Savings April 14, 2010 - 3:26pm Addthis Joshua DeLung What does this project do? Even this small group of initial panels is expected to reduce carbon emissions by 39,631 pounds annually and cut the school's energy costs by a few percentage points. A solar installation on the roof of Drury High School in North Adams, Mass., and an integrated curriculum for students will be the result of $300,000 in Energy Efficiency and Conservation Block Grants, funded by the Recovery Act. North Adams and neighboring Clarksburg, which also sends students to the high school, pooled their $150,000 grants to contribute to the project. "One of the beauties about that building is we have a rough idea of what

227

Ignition methods and apparatus using microwave energy  

SciTech Connect

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.

DeFreitas, Dennis Michael (Oxford, NY); Migliori, Albert (Santa Fe, NM)

1997-01-01T23:59:59.000Z

228

The National Ignition Facility: Status of Construction  

E-Print Network (OSTI)

Bruce Warner Deputy Associate Director, NIF Programs Lawrence Livermore National Laboratory October 11, 2005 #12;NIF-0605-10997 27EIM/cld NIF-0605-10997-L2 27EIM/cld P LLNLLLNL P9266 #12;NIF-0605-10997 27EIM/cld NIF-0605-10997-L28 27EIM/cld P LLNLLLNL National Ignition FacilityNational Ignition Facility P9292 San

229

Infrared Thermographic Study of Laser Ignition  

SciTech Connect

Pyrotechnic ignition has been studied in the past by making a limited number of discrete temperature-time observations during ignition. Present-day infrared scanning techniques make it possible to record thermal profiles, during ignition, with high spacial and temporal resolution. Data thus obtained can be used with existing theory to characterize pyrotechnic materials and to develop more precise kinetic models of the ignition process. Ignition has been studied theoretically and experimentally using various thermal methods. It has been shown that the whole process can, ideally, be divided into two stages. In the first stage, the sample pellet behaves like an inert body heated by an external heat source. The second stage is governed by the chemical reaction in the heated volume produced during the first stage. High speed thermographic recording of the temperature distribution in the test sample during laser ignition makes it possible to calculate the heat content at any instant. Thus, one can actually observe laser heating and the onset of self-sustained combustion in the pellet. The experimental apparatus used to make these observations is described. The temperature distributions recorded are shown to be in good agreement with those predicted by heat transfer theory. Heat content values calculated from the observed temperature distributions are used to calculate thermal and kinetic parameters for several samples. These values are found to be in reasonable agreement with theory.

Mohler, Jonathan H.; Chow, Charles T. S.

1986-07-01T23:59:59.000Z

230

Historical Aspects of Soil Chemistry Donald L. Sparks1  

E-Print Network (OSTI)

12 Historical Aspects of Soil Chemistry Donald L. Sparks1 The Origins of Agricultural Chemistry: The Forerunner of Soil Chemistry In ancient times Aristotle proposed that plants derive nourishment from is food; the constitution of soils; and the manner in which lands are enriched by manure, or rendered

Sparks, Donald L.

231

X-ray and EUV Emission Studies of Copper Vacuum Spark Plasma  

SciTech Connect

A vacuum spark system with a copper anode and electrode of gap 1.5 mm is investigated for the purpose of developing it as a possible radiation source for Next Generation Lithography (NGL). At discharge voltage in the range of 10 to 15 kV and an ambient pressure of about 10{sup -3} mbar, both X-ray (measured by PIN diode) and extreme ultraviolet, EUV (measured by SXUV5A with integrated filter) can be measured simultaneously when good pinching discharge as indicated by sharp dip in the waveform of the rate of current is achieved. For discharge with mild pinching, only EUV emission is observed.

Chan, L. S.; Ghomeishi, M.; Yap, S. L.; Wong, C. S. [Plasma Research Laboratory, Physics Department, Faculty of Science, University of Malaya, 50603 KualaLumpur (Malaysia)

2010-07-07T23:59:59.000Z

232

Modeling of homogeneous charge compression ignition (HCCI) of methane  

DOE Green Energy (OSTI)

The operation of piston engines on a compression ignition cycle using a lean, homogeneous charge has many potential attractive features. These include the potential for extremely low NO{sub x} and particulate emissions while maintaining high thermal efficiency and not requiring the expensive high pressure injection system of the typical modem diesel engine. Using the HCT chemical kinetics code to simulate autoignition of methane-air mixtures, we have explored the ignition timing, burn duration, NO{sub x} production, indicated efficiency and power output of an engine with a compression ratio of 15:1 at 1200 and 2400 rpm. HCT was modified to include the effects of heat transfer. This study used a single control volume reaction zone that varies as a function of crank angle. The ignition process is controlled by varying the intake equivalence ratio and varying the residual gas trapping (RGT). RGT is internal exhaust gas recirculation which recycles both heat and combustion product species. It is accomplished by varying the timing of the exhaust valve closure. Inlet manifold temperature was held constant at 330 Kelvins. Results show that there is a narrow range of operational conditions that show promise of achieving the control necessary to vary power output while keeping indicated efficiency above 50% and NO{sub x} levels below 100 ppm.

Smith, J.R.; Aceves, S.M.; Westbrook, C.; Pitz, W.

1997-05-01T23:59:59.000Z

233

Analysis of ignition of a porous energetic material  

SciTech Connect

A theory of ignition is presented to analyze the effect of porosity on the time to ignition of a semi-infinite porous energetic solid subjected to a constant energy flux. An asymptotic perturbation analysis, based on the smallness of the gas-to-solid density ratio and the largeness of the activation energy, is utilized to describe the inert and transition stages leading to thermal runaway. As in the classical study of a nonporous solid, the transition stage consists of three spatial regions in the limit of large activation energy: a thin reactive-diffusive layer adjacent to the exposed surface of the material where chemical effects are first felt, a somewhat thicker transient-diffusive zone, and finally an inert region where the temperature field is still governed solely by conductive heat transfer. Solutions in each region are constructed at each order with respect to the density-ratio parameter and matched to one another using asymptotic matching principles. It is found that the effects of porosity provide a leading-order reduction in the time to ignition relative to that for the nonporous problem, arising from the reduced amount of solid material that must be heated and the difference in thermal conductivities of the solid and gaseous phases. A positive correction to the leading-order ignition-delay time, however, is provided by the convective flow of gas out of the solid, which stems from the effects of thermal expansion and removes energy from the system. The latter phenomenon is absent from the corresponding calculation for the nonporous problem and produces a number of modifications at the next order in the analysis arising from the relative transport effects associated with the gas flow.

Telengator, A.M.; Williams, F.A. [Univ. of California, San Diego, La Jolla, CA (United States). Dept. of Applied Mechanics and Engineering Sciences; Margolis, S.B. [Sandia National Labs., Livermore, CA (United States). Combustion Research Facility

1998-04-01T23:59:59.000Z

234

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

E-Print Network (OSTI)

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 ...

Cheng, Wai K.

235

Effect of directed port air flow on liquid fuel transport in a port fuel injected spark ignition engine  

E-Print Network (OSTI)

With highly efficient modem catalysts, startup HC emissions have become a significant portion of the trip total. Liquid fuel is a major source of HC emissions during the cold start and fast idle period. Thus the control ...

Scaringe, Robert J. (Robert Joseph)

2007-01-01T23:59:59.000Z

236

Regulated Emissions from a High Efficiency Spark-Ignition with Maximum Engine Power at or Below 19 KW.  

E-Print Network (OSTI)

??Previous research has developed a set of high efficiency generator engines converted from a stock automobile engine. These all employed different variations of squish and… (more)

Mackey, Travis J

2013-01-01T23:59:59.000Z

237

Power conditioning development for the National Ignition Facility  

DOE Green Energy (OSTI)

The National Ignition Facility (NIF) is a high energy glass laser system and target chamber that will be used for research in inertial confinement fusion. The 192 beams of the NIF laser system are pumped by over 8600 Xenon flashlamps. The power conditioning system for NIF must deliver nearly 300 MJ of energy to the flashlamps in a cost effective and reliable manner. The present system design has over 200 capacitive energy storage modules that store approximately 1.7 MJ each and deliver that energy through a single switch assembly to 20 parallel sets of two series flashlamps. Although there are many possible system designs, few will meet the aggressive cost goals necessary to make the system affordable. Sandia National Laboratory (SNL) and Lawrence Livermore National Laboratory (LLNL) are developing the system and component technologies that will be required to build the power conditioning system for the National Ignition Facility. This paper will describe the ongoing development activities for the NIF power conditioning system.

Newton, M.A.; Larson, D.W. [Lawrence Livermore National Lab., CA (United States); Wilson, J.M.; Harjes, H.C.; Savage, M.E. [Sandia National Labs., Albuquerque, NM (United States); Anderson, R.L. [American Controls, Inc., San Diego, CA (United States)

1996-10-01T23:59:59.000Z

238

The velocity campaign for ignition on NIF  

SciTech Connect

Achieving inertial confinement fusion ignition requires a symmetric, high velocity implosion. Experiments show that we can reach 95 {+-} 5% of the required velocity by using a 420 TW, 1.6 MJ laser pulse. In addition, experiments with a depleted uranium hohlraum show an increase in capsule performance which suggests an additional 18 {+-} 5 {mu}m/ns of velocity with uranium hohlraums over gold hohlraums. Combining these two would give 99 {+-} 5% of the ignition velocity. Experiments show that we have the ability to tune symmetry using crossbeam transfer. We can control the second Legendre mode (P2) by changing the wavelength separation between the inner and outer cones of laser beams. We can control the azimuthal m = 4 asymmetry by changing the wavelength separation between the 23.5 and 30 degree beams on NIF. This paper describes our 'first pass' tuning the implosion velocity and shape on the National Ignition Facility laser [Moses et al., Phys. Plasmas, 16, 041006 (2009)].

Callahan, D. A.; Meezan, N. B.; Glenzer, S. H.; MacKinnon, A. J.; Benedetti, L. R.; Bradley, D. K.; Celeste, J. R.; Celliers, P. M.; Dixit, S. N.; Doeppner, T.; Dzentitis, E. G.; Glenn, S.; Haan, S. W.; Haynam, C. A.; Hicks, D. G.; Hinkel, D. E.; Jones, O. S.; Landen, O. L.; London, R. A.; MacPhee, A. G. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); and others

2012-05-15T23:59:59.000Z

239

APPLICATION OF FAULT TREE ANALYSIS TO IGNITION OF FIRE  

E-Print Network (OSTI)

ignition, but which, due to human error causing a sufficientfuel is primarily due to human error. For example, a cooke.g. planned ignition f human error comes in e.g. failure of

Teresa Ling, W.C.

2011-01-01T23:59:59.000Z

240

Precision Shock Tuning on the National Ignition Facility  

E-Print Network (OSTI)

Ignition implosions on the National Ignition Facility [ J.?D. Lindl et al. Phys. Plasmas 11 339 (2004)] are underway with the goal of compressing deuterium-tritium fuel to a sufficiently high areal density (?R) to sustain ...

Frenje, Johan A.

Note: This page contains sample records for the topic "ignition system spark" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Focused shock spark discharge drill using multiple electrodes  

DOE Patents (OSTI)

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.

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

1988-01-01T23:59:59.000Z

242

On the ignition of fuel beds by firebrands  

Science Conference Proceedings (OSTI)

... The firebrand ignition apparatus consists of four butane burners and a firebrand mounting probe. The butane flowrate is ...

2006-12-12T23:59:59.000Z

243

Development of nuclear diagnostics for the National Ignition Facility ,,invited...  

E-Print Network (OSTI)

July 2006; published online 5 October 2006 The National Ignition Facility NIF will provide up to 1.8 MJ of laser energy for imploding inertial confinement fusion ICF targets. Ignited NIF targets are expected of nuclear diagnostics in ICF experiments. In 2005, the suite of nuclear-ignition diagnostics for the NIF

244

Indirect Drive Warm-Loaded Ignition Target Design  

SciTech Connect

This document summarizes the Indirect Drive Warm-Loaded Ignition Target design. These targets either use a fill tube or the capsule is strong enough to withstand the room temperature pressure of the DT fuel. Only features that affect the design of the NIF Cryogenic Target System (NCTS) are presented. The design presented is the current thinking and may evolve further. The NCTS should be designed to accommodate a range of targets and target scales, as described here. The interface location between the target and the NCTS cryostat is at the target base / gripper joint, the tamping gas gland/gland joint, and the electrical plug/receptacle joint.

Bernat, T P; Gibson, C R

2004-09-03T23:59:59.000Z

245

Deliberate ignition of hydrogen-air-steam mixtures in condensing steam environments  

DOE Green Energy (OSTI)

Large scale experiments were performed to determine the effectiveness of thermal glow plug igniters to burn hydrogen in a condensing steam environment due to the presence of water sprays. The experiments were designed to determine if a detonation or accelerated flame could occur in a hydrogen-air-steam mixture which was initially nonflammable due to steam dilution but was rendered flammable by rapid steam condensation due to water sprays. Eleven Hydrogen Igniter Tests were conducted in the test vessel. The vessel was instrumented with pressure transducers, thermocouple rakes, gas grab sample bottles, hydrogen microsensors, and cameras. The vessel contained two prototypic engineered systems: (1) a deliberate hydrogen ignition system and (2) a water spray system. Experiments were conducted under conditions scaled to be nearly prototypic of those expected in Advanced Light Water Reactors (such as the Combustion Engineering (CE) System 80+), with prototypic spray drop diameter, spray mass flux, steam condensation rates, hydrogen injection flow rates, and using the actual proposed plant igniters. The lack of any significant pressure increase during the majority of the burn and condensation events signified that localized, benign hydrogen deflagration(s) occurred with no significant pressure load on the containment vessel. Igniter location did not appear to be a factor in the open geometry. Initially stratified tests with a stoichiometric mixture in the top showed that the water spray effectively mixes the initially stratified atmosphere prior to the deflagration event. All tests demonstrated that thermal glow plugs ignite hydrogen-air-steam mixtures under conditions with water sprays near the flammability limits previously determined for hydrogen-air-steam mixtures under quiescent conditions. This report describes these experiments, gives experimental results, and provides interpretation of the results. 12 refs., 127 figs., 16 tabs.

Blanchat, T.K.; Stamps, D.W.

1997-05-01T23:59:59.000Z

246

Design of a deuterium and tritium-ablator shock ignition target for the National Ignition Facility  

SciTech Connect

Shock ignition presents a viable path to ignition and high gain on the National Ignition Facility (NIF). In this paper, we describe the development of the 1D design of 0.5 MJ class, all-deuterium and tritium (fuel and ablator) shock ignition target that should be reasonably robust to Rayleigh-Taylor fluid instabilities, mistiming, and hot electron preheat. The target assumes 'day one' NIF hardware and produces a yield of 31 MJ with reasonable allowances for laser backscatter, absorption efficiency, and polar drive power variation. The energetics of polar drive laser absorption require a beam configuration with half of the NIF quads dedicated to launching the ignitor shock, while the remaining quads drive the target compression. Hydrodynamic scaling of the target suggests that gains of 75 and yields 70 MJ may be possible.

Terry, Matthew R.; Perkins, L. John; Sepke, Scott M. [Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, California 94550 (United States)

2012-11-15T23:59:59.000Z

247

Premature ignition of a rocket motor.  

SciTech Connect

During preparation for a rocket sled track (RST) event, there was an unexpected ignition of the zuni rocket motor (10/9/08). Three Sandia staff and a contractor were involved in the accident; the contractor was seriously injured and made full recovery. The data recorder battery energized the low energy initiator in the rocket.

Moore, Darlene Ruth

2010-10-01T23:59:59.000Z

248

National Ignition Facility Title II Design Plan  

Science Conference Proceedings (OSTI)

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.

Kumpan, S

1997-03-01T23:59:59.000Z

249

Groundbreaking at National Ignition Facility | National Nuclear Security  

NLE Websites -- All DOE Office Websites (Extended Search)

Groundbreaking at National Ignition Facility | National Nuclear Security Groundbreaking at National Ignition Facility | National Nuclear Security Administration Our Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear Navy Emergency Response Recapitalizing Our Infrastructure Continuing Management Reform Countering Nuclear Terrorism About Us Our Programs Our History Who We Are Our Leadership Our Locations Budget Our Operations Media Room Congressional Testimony Fact Sheets Newsletters Press Releases Speeches Events Social Media Video Gallery Photo Gallery NNSA Archive Federal Employment Apply for Our Jobs Our Jobs Working at NNSA Blog Home > About Us > Our History > NNSA Timeline > Groundbreaking at National Ignition Facility Groundbreaking at National Ignition Facility May 29, 1997 Livermore, CA Groundbreaking at National Ignition Facility

250

Fundamentals of Spark-Plasma Sintering: Net-Shaping and Size ...  

Science Conference Proceedings (OSTI)

Net-shaping capabilities and size effects on spark-plasma sintering are analysed both theoretically and experimentally. Modeling and experimentation are ...

251

On the Role of Electric Current in Spark Plasma Sintering of ...  

Science Conference Proceedings (OSTI)

The experimental results are interpreted in the framework of the developed constitutive model of the spark-plasma sintering of conductive powders, taking into ...

252

Spark Plasma Sintering of Tungsten-Rhenium Alloys for Very High ...  

Science Conference Proceedings (OSTI)

In this study, the tungsten-rhenium microstructure was optimized using alternative techniques such as high energy ball milling and spark plasma sintering, which ...

253

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

SciTech Connect

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.

Stolz, C J

2011-03-16T23:59:59.000Z

254

The ePLAS Code for Ignition Studies  

SciTech Connect

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.

Mason, Rodney J

2012-09-20T23:59:59.000Z

255

Visualization of Target Inspection data at the National Ignition Facility  

SciTech Connect

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.

Potter, D; Antipa, N

2012-02-16T23:59:59.000Z

256

Optimal Control of the Solid Fuel Ignition Model with H1-Cost  

Science Conference Proceedings (OSTI)

Optimal control problems for the stationary as well as the time-dependent solid fuel ignition model are investigated. Existence of optimal controls is proved, and optimality systems are derived. The analysis is based on a closedness lemma for the exponential ... Keywords: control of exponential nonlinearity, explosion phenomena, optimal control, optimality conditions

Kazufumi Ito; Karl Kunisch

2001-05-01T23:59:59.000Z

257

Spark Plasma Sintering of Fuel Cermets for Nuclear Reactor Applications  

Science Conference Proceedings (OSTI)

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.

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

2011-11-01T23:59:59.000Z

258

Test report for core drilling ignitability testing  

DOE Green Energy (OSTI)

Testing was carried out with the cooperation of Westinghouse Hanford Company and the United States Bureau of Mines at the Pittsburgh Research Center in Pennsylvania under the Memorandum of Agreement 14- 09-0050-3666. Several core drilling equipment items, specifically those which can come in contact with flammable gasses while drilling into some waste tanks, were tested under conditions similar to actual field sampling conditions. Rotary drilling against steel and rock as well as drop testing of several different pieces of equipment in a flammable gas environment were the specific items addressed. The test items completed either caused no ignition of the gas mixture, or, after having hardware changes or drilling parameters modified, produced no ignition in repeat testing.

Witwer, K.S.

1996-08-08T23:59:59.000Z

259

Rapid ignition of fluidized bed boiler  

DOE Patents (OSTI)

A fluidized bed boiler is started up by directing into the static bed of inert and carbonaceous granules a downwardly angled burner so that the hot gases cause spouting. Air is introduced into the bed at a rate insufficient to fluidize the entire bed. Three regions are now formed in the bed, a region of lowest gas resistance, a fluidized region and a static region with a mobile region at the interface of the fluidized and static regions. Particles are transferred by the spouting action to form a conical heap with the carbonaceous granules concentrated at the top. The hot burner gases ignite the carbonaceous matter on the top of the bed which becomes distributed in the bed by the spouting action and bed movement. Thereafter the rate of air introduction is increased to fluidize the entire bed, the spouter/burner is shut off, and the entire fluidized bed is ignited.

Osborn, Liman D. (Alexandria, VA)

1976-12-14T23:59:59.000Z

260

Laser-plasma interactions for fast ignition  

E-Print Network (OSTI)

In the electron-driven fast-ignition approach to inertial confinement fusion, petawatt laser pulses are required to generate MeV electrons that deposit several tens of kilojoules in the compressed core of an imploded DT shell. We review recent progress in the understanding of intense laser plasma interactions (LPI) relevant to fast ignition. Increases in computational and modeling capabilities, as well as algorithmic developments have led to enhancement in our ability to perform multi-dimensional particle-in-cell (PIC) simulations of LPI at relevant scales. We discuss the physics of the interaction in terms of laser absorption fraction, the laser-generated electron spectra, divergence, and their temporal evolution. Scaling with irradiation conditions such as laser intensity are considered, as well as the dependence on plasma parameters. Different numerical modeling approaches and configurations are addressed, providing an overview of the modeling capabilities and limitations. In addition, we discuss the compa...

Kemp, A J; Debayle, A; Johzaki, T; Mori, W B; Patel, P K; Sentoku, Y; Silva, L O

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ignition system spark" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Design and reality for NIF ignition targets  

SciTech Connect

Advances in ICF experiments and modeling have led to improved understanding of the growth of instabilities during capsule implosion and the effects on capsule performance. This has led to more refined specifications on the characteristics of igniting capsules, all of which have solid D-T fuel layers. These specifications involve a trade-off between the interior ice surface structure, outer capsule surface structure, and time-dependent drive asymmetry.

Bernat, T.P.

1996-05-31T23:59:59.000Z

262

Multiple laser pulse ignition method and apparatus  

DOE Patents (OSTI)

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. 18 figs.

Early, J.W.

1998-05-26T23:59:59.000Z

263

Multiple laser pulse ignition method and apparatus  

DOE Patents (OSTI)

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.

Early, James W. (Los Alamos, NM)

1998-01-01T23:59:59.000Z

264

National Ignition Campaign (NIC) Precision Tuning Series Shock Timing Experiments  

Science Conference Proceedings (OSTI)

A series of precision shock timing experiments have been performed on NIF. These experiments continue to adjust the laser pulse shape and employ the adjusted cone fraction (CF) in the picket (1st 2 ns of the laser pulse) as determined from the re-emit experiment series. The NIF ignition laser pulse is precisely shaped and consists of a series of four impulses, which drive a corresponding series of shock waves of increasing strength to accelerate and compress the capsule ablator and fuel layer. To optimize the implosion, they tune not only the strength (or power) but also, to sub-nanosecond accuracy, the timing of the shock waves. In a well-tuned implosion, the shock waves work together to compress and heat the fuel. For the shock timing experiments, a re-entrant cone is inserted through both the hohlraum wall and the capsule ablator allowing a direct optical view of the propagating shocks in the capsule interior using the VISAR (Velocity Interferometer System for Any Reflector) diagnostic from outside the hohlraum. To emulate the DT ice of an ignition capsule, the inside of the cone and the capsule are filled with liquid deuterium.

Robey, H F; Celliers, P M

2011-07-19T23:59:59.000Z

265

Characterization of in situ oil shale retorts prior to ignition  

DOE Patents (OSTI)

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.

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

1984-01-01T23:59:59.000Z

266

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

DOE Patents (OSTI)

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.

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

267

Capsule performance optimization in the National Ignition Campaign  

Science Conference Proceedings (OSTI)

A capsule performance optimization campaign will be conducted at the National Ignition Facility [G. H. Miller et al., Nucl. Fusion 44, 228 (2004)] to substantially increase the probability of ignition by laser-driven hohlraums [J. D. Lindl et al., Phys. Plasmas 11, 339 (2004)]. The campaign will experimentally correct for residual uncertainties in the implosion and hohlraum physics used in our radiation-hydrodynamic computational models before proceeding to cryogenic-layered implosions and ignition attempts. The required tuning techniques using a variety of ignition capsule surrogates have been demonstrated at the OMEGA facility under scaled hohlraum and capsule conditions relevant to the ignition design and shown to meet the required sensitivity and accuracy. In addition, a roll-up of all expected random and systematic uncertainties in setting the key ignition laser and target parameters due to residual measurement, calibration, cross-coupling, surrogacy, and scale-up errors has been derived that meets the required budget.

Landen, O. L.; Bradley, D. K.; Braun, D. G.; Callahan, D. A.; Celliers, P. M.; Collins, G. W.; Dewald, E. L.; Divol, L.; Glenzer, S. H.; Hamza, A.; Hicks, D. G.; Izumi, N.; Jones, O. S.; Kirkwood, R. K.; Michel, P.; Milovich, J.; Munro, D. H.; Robey, H. F.; Spears, B. K.; Thomas, C. A. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

2010-05-15T23:59:59.000Z

268

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

SciTech Connect

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.

Ma, T

2010-04-21T23:59:59.000Z

269

Optical key system  

Science Conference Proceedings (OSTI)

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.

Hagans, K.G.; Clough, R.E.

2000-04-25T23:59:59.000Z

270

Optical key system  

DOE Patents (OSTI)

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.

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

2000-01-01T23:59:59.000Z

271

Modeling the Number of Ignitions Following an Earthquake: Developing...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Ignitions Following an Earthquake: Developing Prediction Limits for Overdispersed Count Data Authors: Elizabeth J. Kelly and Raymond N. Tell Intended Use: Deliverable to SB-TS:...

272

Edward Moses to lead Fusion Ignition Science and Applications...  

NLE Websites -- All DOE Office Websites (Extended Search)

1 For immediate release: 10012013 | NR-13-10-01 Edward Moses to lead Fusion Ignition Science and Applications research effort -- Jeff Wisoff appointed acting principal associate...

273

Argonne TTRDC - Engines - Compression-Ignition - diesel, fuel...  

NLE Websites -- All DOE Office Websites (Extended Search)

Compression Ignition Engines Clean Diesel Technologies for Greener Performance Mechanical engineer Alan Kastengren examines a diesel injection nozzle used in Argonne's X-ray spray...

274

Ignition of an overheated, underdense, fusioning tokamak plasma  

SciTech Connect

Methods of igniting an overheated but underdense D-T plasma core with a cold plasma blanket are investigated using a simple two-zone model with a variety of transport scaling laws, and also using a one-dimensional transport code. The power consumption of neutral-beam injectors required to produce ignition can be reduced significantly if the underdense core plasma is heated to temperatures much higher than the final equilibrium ignition values, followed by fueling from a cold plasma blanket. It is also found that the allowed impurity concentration in the initial hot core can be greater than normally permitted for ignition provided that the blanket is free from impurities.

Singer, C.E.; Jassby, D.L.; Hovey, J.

1979-08-01T23:59:59.000Z

275

Project: Reduced Ignition and Flame Spread with Nano ...  

Science Conference Proceedings (OSTI)

... to ignition, time to extinction, and time to smoke ... of innovative technologies to develop cost-effective fire ... [6] Förster resonance energy transfer (FRET ...

2013-12-12T23:59:59.000Z

276

On the Piloted Ignition of Solid Fuels in Spacecraft Environments  

E-Print Network (OSTI)

importance of the heat transfer processes in the ignition ofa measure of the heat transfer processes involved. Aninsight on the heat and mass transfer processes involved in

Fereres-Rapoport, Sonya M.

2011-01-01T23:59:59.000Z

277

NIF achieves record laser energy in pursuit of fusion ignition...  

National Nuclear Security Administration (NNSA)

achieves record laser energy in pursuit of fusion ignition | National Nuclear Security Administration Our Mission Managing the Stockpile Preventing Proliferation Powering the...

278

NETL: Releases & Briefs - Laser ignition for lean-burn engines  

NLE Websites -- All DOE Office Websites (Extended Search)

Energy Technology Laboratory have successfully operated a laser-spark lean-burn natural gas reciprocating engine. Development of lean-burn engines is driven by demand for higher...

279

Electron generation and transport in intense relativistic laser-plasma interactions relevant to fast ignition ICF  

E-Print Network (OSTI)

ix Figure 1.10: (a) The NIF ignition scale cone-guided FINational Ignition Facility (NIF) experiments will focus onthe injection Figure 1.10: (a) The NIF ignition scale cone-

Ma, Tammy Yee Wing

2010-01-01T23:59:59.000Z

280

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

DOE Green Energy (OSTI)

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.

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

Note: This page contains sample records for the topic "ignition system spark" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Demonstration of the shock-timing technique for ignition targets on the National Ignition Facility  

Science Conference Proceedings (OSTI)

A high-performance inertial confinement fusion capsule is compressed by multiple shock waves before it implodes. To minimize the entropy acquired by the fuel, the strength and timing of those shock waves must be accurately controlled. Ignition experiments at the National Ignition Facility (NIF) will employ surrogate targets designed to mimic ignition targets while making it possible to measure the shock velocities inside the capsule. A series of experiments on the OMEGA laser facility [Boehly et al., Opt. Commun. 133, 495 (1997)] validated those targets and the diagnostic techniques proposed. Quartz was selected for the diagnostic window and shock-velocity measurements were demonstrated in Hohlraum targets heated to 180 eV. Cryogenic experiments using targets filled with liquid deuterium further demonstrated the entire timing technique in a Hohlraum environment. Direct-drive cryogenic targets with multiple spherical shocks were used to further validate this technique, including convergence effects at relevant pressures (velocities) and sizes. These results provide confidence that shock velocity and timing can be measured in NIF ignition targets, allowing these critical parameters to be optimized.

Boehly, T. R.; Hu, S. X.; Morozas, J. A.; Sangster, T. C. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14645 (United States); Munro, D.; Celliers, P. M.; Hicks, D. G.; Collins, G. W.; Robey, H. F.; Landen, O. L. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Olson, R. E. [Sandia National Laboratories, Albuquerque, New Mexico 87123 (United States); Goncharov, V. N. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14645 (United States); Department of Mechanical Engineering, University of Rochester, New York 14645 (United States); Meyerhofer, D. D. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14645 (United States); Department of Mechanical Engineering, University of Rochester, New York 14645 (United States); Department of Physics and Astronomy, University of Rochester, New York 14645 (United States)

2009-05-15T23:59:59.000Z

282

Ignition of hydrogen/air mixing layer in turbulent flows  

DOE Green Energy (OSTI)

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.

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

283

Dynamics of periodic structures in an extended laser spark  

SciTech Connect

The time scans of the intrinsic and scattered heating radiations of plasma foci, arising in the spark channel of the optical gas breakdown in a Bessel beam, were investigated. The experiments were carried out in argon at atmospheric pressure by using the heating radiation from a powerful nanosecond neodymium laser. The influence of independent preionisation and of the presence of aerosol particles was studied separately. The results indicate the appearance of bright foci against the background of the initially almost homogeneous plasma. The location of the foci in the longitudinal direction and the dynamics of the emitted radiation by them make it possible to assign the observed inhomogeneities to two quasi-periodic structures with periods differing almost by an order of magnitude. The above structures result from the operation of various mechanisms of the formation of inhomogeneities. (interaction of laser radiation with matter. laser plasma)

Bychkov, S S; Gorlov, S V; Makarov, A V; Margolin, L Ya; Pyatnitskii, Lev N; Tal'virskii, A D [Scientific Association for High Temperatures, Russian Academy of Sciences, Moscow (Russian Federation)

1999-03-31T23:59:59.000Z

284

Low emissions compression ignited engine technology  

DOE Patents (OSTI)

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.

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

285

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

SciTech Connect

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.

Jeff Wishart; Matthew Shirk

2012-12-01T23:59:59.000Z

286

Impact of key design parameters on neutron wall load in an ignited tokamak  

SciTech Connect

A study was performed to determine the impact of key design parameters on neutron wall load in an ignited deuterium-tritium (D-T) tokamak. Systems effects of parameter variations were determined using the Fusion Engineering Design Center (FEDC) Systems Code. Poloidal variations in neutron wall load were determined using the Monte Carlo Code for Neutron and Photon Transport (MCNP). The marked impact of key design parameters is quantitatively shown.

Reiersen, W.T.

1983-01-01T23:59:59.000Z

287

Shock Timing Techniques for Ignition Capsules on the NIF  

Science Conference Proceedings (OSTI)

Results from a series of shock trajectory measurements in planar liquid deuterium targets will set the pulse shape they use for ignition capsules at the National Ignition Facility. They discuss outstanding issues for this concept, in particular, ideas for certifying that the drive on a planar sample is the same as on a spherical capsule.

Munro, D H; Haan, S W; Collins, G W; Celliers, P M

2003-09-02T23:59:59.000Z

288

Planning for the National Ignition Campaign on NIF Presentation to  

E-Print Network (OSTI)

Planning for the National Ignition Campaign on NIF Presentation to Fusion Power Associates Annual Meeting Dec 3-4, 2008 Lawrence Livermore National Laboratory John Lindl NIF Programs Chief Scientist a clearly defined path forward to achievement of ignition on NIF ·An extensive scientific data base forms

289

National Ignition Facility project acquisition plan  

SciTech Connect

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.

Callaghan, R.W.

1996-04-01T23:59:59.000Z

290

PBXN-9 Ignition Kinetics and Deflagration Rates  

SciTech Connect

The ignition kinetics and deflagration rates of PBXN-9 were measured using specially designed instruments at LLNL and compared with previous work on similar HMX based materials. Ignition kinetics were measured based on the One Dimensional Time-to-Explosion combined with ALE3D modeling. Results of these experiments indicate that PBXN-9 behaves much like other HMX based materials (i.e. LX-04, LX-07, LX-10 and PBX-9501) and the dominant factor in these experiments is the type of explosive, not the type of binder/plasticizer. In contrast, the deflagration behavior of PBXN-9 is quite different from similar high weight percent HMX based materials (i.e LX-10, LX-07 and PBX-9501). PBXN-9 burns in a laminar manner over the full pressure range studied (0-310 MPa) unlike LX-10, LX-07, and PBX-9501. The difference in deflagration behavior is attributed to the nature of the binder/plasticizer alone or in conjunction with the volume of binder present in PBXN-9.

Glascoe, E; Maienschein, J; Burnham, A; Koerner, J; Hsu, P; Wemhoff, A

2008-04-24T23:59:59.000Z

291

Future prospects for compression ignition fuel in California : fuel-related implications of possible pathways to mitigation of public health threats.  

DOE Green Energy (OSTI)

This paper documents methods and results of an investigation of the options for and year 2010 consequences of possible new limitations on the use of diesel fuel in California, USA. California's Air Resources Board will undertake a risk management process to determine steps necessary to protect the health and safety of the public from carcinogenic species resident on diesel combustion exhaust particles. Environmental activist groups continue to call for the elimination of diesel fuel in California and other populous states. It is the declared intention of CARB not to ban or restrict diesel fuel, per se, at this time. Thus, two ''mid-course'' strategies now appear feasible: (1) Increased penetration of natural gas, LPG, and possibly lower alcohols into the transportation fuels market, to the extent that some Cl applications would revert to spark-ignition (SI) engines. (2) New specifications requiring diesel fuel reformulation based on more detailed investigation of exhaust products of individual diesel fuel constituents.

Eberhardt, J. J.; Rote, D. M.; Saricks, C. L.; Stodolsky, F.

1999-04-08T23:59:59.000Z

292

Transparent yttrium aluminium garnet obtained by spark plasma sintering of lyophilized gels  

Science Conference Proceedings (OSTI)

Lyophilized YAG gel, synthesized by the coprecipitation technique, has been sintered to transparency by spark plasma sintering method at 1500°C. Whereas conventionally dried gels show large agglomerates, over 1 µm, powders from lyophilized ...

M. Suárez; A. Fernández; J. L. Menéndez; R. Torrecillas

2009-01-01T23:59:59.000Z

293

Characterisation of high aspect ratio non-conductive ceramic microstructures made by spark erosion  

Science Conference Proceedings (OSTI)

The spark erosion process is widely used for micro structuring. Its possibility to structure materials independent of their material properties like high hardness or melting temperature enables to address a large material diversity. However the process ...

T. Hösel; P. Cvancara; T. Ganz; C. Müller; H. Reinecke

2011-02-01T23:59:59.000Z

294

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

E-Print Network (OSTI)

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 ...

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

2005-01-01T23:59:59.000Z

295

The National Ignition Facility Data Requirements Tim Frazier and Alice Koniges, LLNL  

NLE Websites -- All DOE Office Websites (Extended Search)

Ignition Facility Data Requirements Ignition Facility Data Requirements Tim Frazier and Alice Koniges, LLNL SC08 BOF: Computing with Massive and Persistent Data LLNL-PRES-408909. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52- 07NA27344 2 Target chamber One Terabyte of data to be downloaded in ~50 Minutes for each shot. 5 Full Aperture Backscatter Diagnostic Instrument Manipulator (DIM) Diagnostic Instrument Manipulator (DIM) X-ray imager Streaked x-ray detector VISAR Velocity Measurements Static x-ray imager FFLEX Hard x-ray spectrometer Near Backscatter Imager DANTE Soft x-ray temperature Diagnostic Alignment System Cross Timing System Each Diagnostic Produces Data that Requires Analysis 6 Tools are being built to manage and integrate:

296

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

DOE Patents (OSTI)

This disclosure describes 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. It is comprised of (1) 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 (2) 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.

McLean, W.J.; Thorne, L.R.; Volponi, J.V.

1986-06-10T23:59:59.000Z

297

National Ignition Facility and Managing Location, Component, and State  

SciTech Connect

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.

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

2011-07-25T23:59:59.000Z

298

Fast Camera Imaging of Hall Thruster Ignition  

SciTech Connect

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

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

2011-02-24T23:59:59.000Z

299

Director of the National Ignition Facility, Lawrence Livermore National  

NLE Websites -- All DOE Office Websites (Extended Search)

Director of the National Ignition Facility, Lawrence Livermore National Director of the National Ignition Facility, Lawrence Livermore National Laboratory | National Nuclear Security Administration Our Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear Navy Emergency Response Recapitalizing Our Infrastructure Continuing Management Reform Countering Nuclear Terrorism About Us Our Programs Our History Who We Are Our Leadership Our Locations Budget Our Operations Media Room Congressional Testimony Fact Sheets Newsletters Press Releases Speeches Events Social Media Video Gallery Photo Gallery NNSA Archive Federal Employment Apply for Our Jobs Our Jobs Working at NNSA Blog Home > About Us > Who We Are > In The Spotlight > Edward Moses Director of the National Ignition Facility, Lawrence Livermore National Laboratory

300

Hydrogen-assisted catalytic ignition characteristics of different fuels  

SciTech Connect

Hydrogen-assisted catalytic ignition characteristics of methane (CH{sub 4}), n-butane (n-C{sub 4}H{sub 10}) and dimethyl ether (DME) were studied experimentally in a Pt-coated monolith catalytic reactor. It is concluded that DME has the lowest catalytic ignition temperature and the least required H{sub 2} flow, while CH{sub 4} has the highest catalytic ignition temperature and the highest required H{sub 2} flow among the three fuels. (author)

Zhong, Bei-Jing; Yang, Fan [Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Engineering Mechanics, Tsinghua University, Beijing 100084 (China); Yang, Qing-Tao [Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Engineering Mechanics, Tsinghua University, Beijing 100084 (China); China Aerodynamics Research and Development Center, Mianyang 621000 (China)

2010-10-15T23:59:59.000Z

Note: This page contains sample records for the topic "ignition system spark" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Gas flow stabilized megavolt spark gap for repetitive pulses  

SciTech Connect

A high voltage spark gap switch including a housing having first and second end walls being spaced apart by a predetermined distance. A first electrode is positioned on the first end wall and a second electrode is positioned on the second end wall. The first and second electrodes are operatively disposed relative to each other and are spaced apart by a predetermined gap. An inlet conduit is provided for supplying gas to the first electrode. The conduit includes a nozzle for dispersing the gas in the shape of an annular jet. The gas is supplied into the housing at a predetermined velocity. A venturi housing is disposed within the second electrode. An exhaust conduit is provided for discharging gas and residue from the housing. The gas supplied at the predetermined velocity to the housing through the inlet conduit and the nozzle in an annular shape traverses the gap between the first and second electrodes and entrains low velocity gas within the housing decreasing the velocity of the gas supplied to the housing and increasing the diameter of the annular shape. The venturi disposed within the second electrode recirculates a large volume of gas to clean and cool the surface of the electrodes.

Lawson, Robert N. (Albuquerque, NM); O' Malley, Martin W. (Albuquerque, NM); Rohwein, Gerald J. (Albuquerque, NM)

1986-01-01T23:59:59.000Z

302

National Ignition Facility & Photon Science - Bringing Star Power to Earth  

NLE Websites -- All DOE Office Websites (Extended Search)

NIF Go NIF Go LLNL Logo Lawrence Livermore National Laboratory LLNL Home NIF Home LIFE Home Jobs Site Map Contact News Press Releases In the News Status Update Media Assistance About Us National Ignition Facility About NIF How NIF Works The Seven Wonders of NIF Building NIF An Engineering Marvel NIFFY Early Light Collaborators Status Visiting NIF Missions National Security Energy for the Future Understanding the Universe People The People of NIF Awards NIF Professor Sabbatical Opportunities NIF Online Store Programs National Ignition Campaign How to Make a Star (ICF) Target Physics Target Fabrication Cryogenic Target System Diagnostics Participants Photon Science & Applications Advanced Optics Advanced Radiography Directed Energy Fusion Energy Inertial Fusion Energy How IFE Works Science at the Extremes

303

Deliberate ignition of hydrogen-air-steam mixtures under conditions of rapidly condensing steam  

DOE Green Energy (OSTI)

A series of experiments was conducted to determine hydrogen combustion behavior under conditions of rapidly condensing steam caused by water sprays. Experiments were conducted in the Surtsey facility under conditions that were nearly prototypical of those that would be expected in a severe accident in the CE System 80+ containment. Mixtures were initially nonflammable owing to dilution by steam. The mixtures were ignited by thermal glow plugs when they became flammable after sufficient steam was removed by condensation caused by water sprays. No detonations or accelerated flame propagation was observed in the Surtsey facility. The combustion mode observed for prototypical mixtures was characterized by multiple deflagrations with relatively small pressure rises. The thermal glow plugs were effective in burning hydrogen safely by igniting the gases as the mixtures became marginally flammable.

Blanchat, T.; Stamps, D.

1995-01-01T23:59:59.000Z

304

Relativistic electron beam transport for fast ignition relevant scenarios  

E-Print Network (OSTI)

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 ...

Cottrill, Larissa A

2009-01-01T23:59:59.000Z

305

Frictionally induced ignition processes in drop and skid tests  

SciTech Connect

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.

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

2010-01-01T23:59:59.000Z

306

National Ignition Facility makes history with record 500 terawatt...  

NLE Websites -- All DOE Office Websites (Extended Search)

National Ignition Facility makes history with record 500 terawatt shot Breanna Bishop, LLNL, (925) 423-9802, bishop33@llnl.gov Printer-friendly The preamplifiers of the National...

307

Ignition technique for an in situ oil shale retort  

DOE Patents (OSTI)

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.

Cha, Chang Y. (Golden, CO)

1983-01-01T23:59:59.000Z

308

Farm scale biogas-fueled engine/induction generator system  

Science Conference Proceedings (OSTI)

A 3.6 liter spark ignition engine coupled to an induction generator produced 21 kW of electric power at 1260 rpm operating on biogas (55% methane, 45% carbon dioxide). Power output increased by 3.55 kW for a 10 rpm increase in shaft speed. Operating at over 16 kW output, power factor was greater than .8 and generator efficiency was greater than 85%. Engine operation is insensitive to small changes in spark advance. Recommended spark advance for a biogas engine is about 45/sup 0/. Minimum brake specific fuel consumption of 270 g CH/sub 4//kWh occurs at a manifold vacuum of 5 cmHg and an equivalence ratio in the range of .6 to .8.

Stahl, T.; Fischer, J.R.; Harris, F.D.

1982-12-01T23:59:59.000Z

309

Optimally Controlled Flexible Fuel Powertrain System  

DOE Green Energy (OSTI)

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.

Hakan Yilmaz; Mark Christie; Anna Stefanopoulou

2010-12-31T23:59:59.000Z

310

ARPA-E Sparks Connections at the Southwest Energy Innovation Forum |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

ARPA-E Sparks Connections at the Southwest Energy Innovation Forum ARPA-E Sparks Connections at the Southwest Energy Innovation Forum ARPA-E Sparks Connections at the Southwest Energy Innovation Forum October 21, 2010 - 11:29am Addthis John Schueler John Schueler Former New Media Specialist, Office of Public Affairs While many of the policy decisions that shape our energy future are made in Washington, almost all of the important work of actually developing and deploying the innovative and advanced technologies we need takes place in labs and at universities across the country. That's why the Advanced Research Projects Agency-Energy (ARPA-E) recently partnered with Arizona State University and the Kauffman Foundation to organize the inaugural Southwest Energy Innovation Forum. The event brought together scientific researchers in universities and national labs, executives from industry,

311

Imaging VISAR diagnostic for the National Ignition Facility (NIF)  

Science Conference Proceedings (OSTI)

The National Ignition Facility (NIF) requires diagnostics to analyze high-energy density physics experiments. A VISAR (Velocity Interferometry System for Any Reflector) diagnostic has been designed to measure shock velocities, shock breakout times, and shock emission of targets with sizes from 1 to 5 mm. An 8-inch-diameter fused silica triplet lens collects light at f/3 inside the 30-foot-diameter vacuum chamber. The optical relay sends the image out an equatorial port, through a 2-inch-thick vacuum window, and into two interferometers. A 60-kW VISAR probe laser operates at 659.5 nm with variable pulse width. Special coatings on the mirrors and cutoff filters are used to reject the NIF drive laser wavelengths and to pass a band of wavelengths for VISAR, passive shock breakout light, or thermal imaging light (bypassing the interferometers). The first triplet can be no closer than 500 mm from the target chamber center and is protected from debris by a blast window that is replaced after every event. The front end of the optical relay can be temporarily removed from the equatorial port, allowing other experimenters to use that port. A unique resolution pattern has been designed to validate the VISAR diagnostic before each use. All optical lenses are on kinematic mounts so that the pointing accuracy of the optical axis can be checked. Seven CCD cameras monitor the diagnostic alignment.

Malone, R M; Bower, J R; Bradley, D K; Capelle, G A; Celeste, J R; Celliers, P M; Collins, G W; Eckart, M J; Eggert, J H; Frogget, B C; Guyton, R L; Hicks, D G; Kaufman, M I; MacGowan, B J; Montelongo, S; Ng, E W; Robinson, R B; Tunnell, T W; Watts, P W; Zapata, P G

2004-08-30T23:59:59.000Z

312

Methane ignition catalyzed by in situ generated palladium nanoparticles  

SciTech Connect

Catalytic ignition of methane over the surfaces of freely-suspended and in situ generated palladium nanoparticles was investigated experimentally and numerically. The experiments were conducted in a laminar flow reactor. The palladium precursor was a compound (Pd(THD){sub 2}, THD: 2,2,6,6-tetramethyl-3,5-heptanedione) dissolved in toluene and injected into the flow reactor as a fine aerosol, along with a methane-oxygen-nitrogen mixture. For experimental conditions chosen in this study, non-catalytic, homogeneous ignition was observed at a furnace temperature of {proportional_to}1123 K, whereas ignition of the same mixture with the precursor was found to be {proportional_to}973 K. In situ production of Pd/PdO nanoparticles was confirmed by scanning mobility, transmission electron microscopy and X-ray photoelectron spectroscopy analyses of particles collected at the reactor exit. The catalyst particle size distribution was log-normal. Depending on the precursor loading, the median diameter ranged from 10 to 30 nm. The mechanism behind catalytic ignition was examined using a combined gas-phase and gas-surface reaction model. Simulation results match the experiments closely and suggest that palladium nanocatalyst significantly shortens the ignition delay times of methane-air mixtures over a wide range of conditions. (author)

Shimizu, T.; Abid, A.D.; Poskrebyshev, G.; Wang, H. [Department of Aerospace and Mechanical Engineering, University of Southern California, Los Angeles, CA 90089 (United States); Nabity, J.; Engel, J.; Yu, J. [TDA Research, Inc., 12345 W. 52nd Ave, Wheat Ridge, CO 80033 (United States); Wickham, D. [Reaction Systems, LLC, 19039 E. Plaza Drive, Suite 290, Parker, CO 80134 (United States); Van Devener, B.; Anderson, S.L. [Department of Chemistry, University of Utah, Salt Lake City, UT 84112 (United States); Williams, S. [Air Force Research Laboratory, Mail Stop RZA, 1950 Fifth Street, WPAFB, OH 45433 (United States)

2010-03-15T23:59:59.000Z

313

THE AUTOIGNITION OF CYCLOPENTANE IN AN IGNITION QUALITY TESTER  

Science Conference Proceedings (OSTI)

Cyclopentane, a flammable hydrocarbon, is being considered as a working fluid for waste heat recovery applications using Organic Rankine Cycles with Direct Evaporators. A postulated failure mode consisting of a pinhole leak in a heat exchanger tube raises safety concerns due to autoignition of the working fluid. The ignition delay time (IDT) of cyclopentane was measured using an Ignition Quality Test™ (IQT™) device. Hot, vitiated air was used to simulate turbine exhaust gas (TEG). Experiments were conducted in accordance with ASTM D6890 (with exception to charge pressure and temperature) to determine ignition delay of the fuel at atmospheric pressure for vitiated air (13.3% oxygen). The test matrixencompassed equivalence ratios from 0.5 to 5.0 and chamber temperatures ranging from 673 to 823 K to establish a set of ignition delay curves. IDT was observed to decrease with increasing temperature and equivalence ratio. For the cases tested, no ignition was observed at temperatures at or below 723 K or at an equivalence ratio of 0.5.

Donna Post Guillen

2012-08-01T23:59:59.000Z

314

Evaluating the ignition sensitivity of thermal battery heat pellets  

DOE Green Energy (OSTI)

Thermal batteries are activated by the ignition of heat pellets. If the heat pellets are not sensitive enough to the ignition stimulus, the thermal battery will not activate, resulting in a dud. Thus, to assure reliable thermal batteries, it is important to demonstrate that the pellets have satisfactory ignition sensitivity by testing a number of specimens. There are a number of statistical methods for evaluating the sensitivity of a device to some stimulus. Generally, these methods are applicable to the situation in which a single test is destructive to the specimen being tested, independent of the outcome of the test. In the case of thermal battery heat pellets, however, tests that result in a nonresponse do not totally degrade the specimen. This peculiarity provides opportunities to efficiently evaluate the ignition sensitivity of heat pellets. In this paper, a simple strategy for evaluating heat pellet ignition sensitivity (including experimental design and data analysis) is described. The relatively good asymptotic and small-sample efficiencies of this strategy are demonstrated.

Thomas, E.V.

1993-09-01T23:59:59.000Z

315

THE EFFECTS OF HYDROGEN ADDITION AND INTAKE-INDUCED SWIRL ON THE CHARACTERISTICS OF NATURAL GAS COMBUSTION IN A SINGLE-CYLINDER SPARK-IGNITED ENGINE.  

E-Print Network (OSTI)

??Compressed natural gas (CNG) is an alternative fuel of interest for internal combustion engines (ICEs) in the mass transit and vocational applications. Increasingly, due to… (more)

Corrigan, Melanie

2011-01-01T23:59:59.000Z

316

Shock timing on the National Ignition Facility: First Experiments  

Science Conference Proceedings (OSTI)

An experimental campaign to tune the initial shock compression sequence of capsule implosions on the National Ignition Facility (NIF) was initiated in late 2010. The experiments use a NIF ignition-scale hohlraum and capsule that employs a reentrant cone to provide optical access to the shocks as they propagate in the liquid deuterium-filled capsule interior. The strength and timing of the shock sequence is diagnosed with velocity interferometry that provides target performance data used to set the pulse shape for ignition capsule implosions that follow. From the start, these measurements yielded significant new information on target performance, leading to improvements in the target design. We describe the results and interpretation of the initial tuning experiments.

Celliers, P M; Robey, H F; Boehly, T R; Alger, E; Azevedo, S; Berzins, L V; Bhandarkar, S D; Bowers, M W; Brereton, S J; Callahan, D; Castro, C; Chandrasekaran, H; Choate, C; Clark, D; Coffee, K R; Datte, P S; Dewald, E L; DiNicola, P; Dixit, S; Doeppner, T; Dzenitis, E; Edwards, M J; Eggert, J H; Fair, J; Farley, D R; Frieders, G; Gibson, C R; Giraldez, E; Haan, S; Haid, B; Hamza, A V; Haynam, C; Hicks, D G; Holunga, D M; Horner, J B; Jancaitis, K; Jones, O S; Kalantar, D; Kline, J L; Krauter, K G; Kroll, J J; LaFortune, K N; Pape, S L; Malsbury, T; Maypoles, E R; Milovich, J L; Moody, J D; Moreno, K; Munro, D H; Nikroo, A; Olson, R E; Parham, T; Pollaine, S; Radousky, H B; Ross, G F; Sater, J; Schneider, M B; Shaw, M; Smith, R F; Thomas, C A; Throop, A; Town, R J; Trummer, D; Van Wonterghem, B M; Walters, C F; Widmann, K; Widmayer, C; Young, B K; Atherton, L J; Collins, G W; Landen, O L; Lindl, J D; MacGowan, B J; Meyerhofer, D D; Moses, E I

2011-10-24T23:59:59.000Z

317

WILDFIRE IGNITION RESISTANCE ESTIMATOR WIZARD SOFTWARE DEVELOPMENT REPORT  

SciTech Connect

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.

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

2012-10-10T23:59:59.000Z

318

Flash Ignition and Initiation of Explosives-Nanotubes Mixture  

DOE Green Energy (OSTI)

The recent astounding discoveries of ignition in single-walled carbon nanotubes (SWNTs) after exposure to an ordinary photographic flash, (1) other formulations of carbons containing noble metals, (2) and polyaniline nanofibers (3) prompted us to explore a possible further instigation of explosive materials. Here, we report that an ignition and initiation process, further leading to actual detonation, does occur for explosives in lax contact with carbon nanotubes that are prone to opto-thermal activity via a conventional flashbulb. Optical ignition and initiation of explosives could thus far only be accomplished through lasers, (4) with specific characteristic of high power, pulse length, wavelength, and a small target area that greatly inhibit their applications. Our results have the implication that explosives with opto-thermally active SWNTs formulations are new ideal candidates for remote optical triggering of safety apparatus such as the firing of bolts on space shuttles rockets and aircraft exit doors, and for controlled burning of explosives as actuators.

Manaa, M R; Mitchell, A R; Garza, R G; Pagoria, P F; Watkins, B E

2005-05-25T23:59:59.000Z

319

Reactive burn models and ignition & growth concept  

SciTech Connect

Plastic-bonded explosives are heterogeneous materials. Experimentally, shock initiation is sensitive to small amounts of porosity, due to the formation of hot spots (small localized regions of high temperature). This leads to the Ignition and Growth concept, introduced by Lee and Tarver in 1980, as the basis for reactive burn models. A homogeneized burn rate needs to account for three mesoscale physical effects (i) the density of burnt hot spots, which depends on the lead shock strength; (ii) the growth of the burn fronts triggered by hot spots, which depends on the local deflagration speed; (iii) a geometric factor that accounts for the overlap of deflagration wavelets from adjacent hot spots. These effects can be combined and the burn model defined by specifying the reaction progress variable {lambda}(t) as a function of a dimensionless reaction length {tau}{sub hs}(t)/{ell}{sub hs}, rather than by xpecifying an explicit burn rate. The length scale {ell}{sub hs} is the average distance between hot spots, which is proportional to [N{sub hs}(P{sub s})]{sup -1/3}, where N{sub hs} is the number density of hot spots activated by the lead shock. The reaction length {tau}{sub hs}(t) = {line_integral}{sub 0}{sup t} D(P(t'))dt' is the distance the burn front propagates from a single hot spot, where D is the deflagration speed and t is the time since the shock arrival. A key implementation issue is how to determine the lead shock strength in conjunction with a shock capturing scheme. They have developed a robust algorithm for this purpose based on the Hugoniot jump condition for the energy. The algorithm utilizes the time dependence of density, pressure and energy within each cell. The method is independent of the numerical dissipation used for shock capturing. It is local and can be used in one or more space dimensions. The burn model has a small number of parameters which can be calibrated to fit velocity gauge data from shock initiation experiments.

Menikoff, Ralph S [Los Alamos National Laboratory; Shaw, Milton S [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

320

Teaching Soil Chemistry: Challenges and Opportunities. (S02-sparks134217-Oral)  

E-Print Network (OSTI)

Teaching Soil Chemistry: Challenges and Opportunities. (S02-sparks134217-Oral) Abstract: The field of soil chemistry has changed greatly over the past two decades with major emphasis shifting to reactions and processes of environmentally important inorganic and organic species. Moreover, students taking soil

Sparks, Donald L.

Note: This page contains sample records for the topic "ignition system spark" from the National Library of EnergyBeta (NLEBeta).
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321

Exhaust gas recirculation in a homogeneous charge compression ignition engine  

DOE Patents (OSTI)

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.

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

322

Reconfigurable Assembly Station for Precision Manufacture of Nuclear Fusion Ignition Targets  

SciTech Connect

This paper explores the design and testing of a reconfigurable assembly station developed for assembling the inertial confinement nuclear fusion ignition targets that will be fielded in the National Ignition Facility (NIF) laser [1]. The assembly station, referred to as the Flexible Final Assembly Machine (FlexFAM) and shown in Figure 1, is a companion system to the earlier Final Assembly Machine (FAM) [2]. Both machines consist of a manipulator system integrated with an optical coordinate measuring machine (OCMM). The manipulator system has six groups of stacked axis used to manipulate the millimeter-sized target components with submicron precision, and utilizes the same force and torque feedback sensing as the FAM. Real-time dimensional metrology is provided by the OCMM's vision system and through-the-lens (TTL) laser-based height measuring probe. The manually actuated manipulator system of the FlexFAM provides a total of thirty degrees-of-freedom to the target components being assembled predominantly in a cubic centimeter work zone.

Castro, C; Montesanti, R C; Taylor, J S; Hamza, A V; Dzenitis, E G

2009-08-11T23:59:59.000Z

323

Preparation for Ignition Experiments on the NIF Fusion Power Associates Annual Meeting  

E-Print Network (OSTI)

Preparation for Ignition Experiments on the NIF Fusion Power Associates Annual Meeting December 4-5, 2007 John Lindl NIF and Photon Science Directorate Chief Scientist Lawrence Livermore National chance for ignition in early NIF operations · The initial ignition experiments only scratch the surface

324

OMEGA ICF experiments and preparation for direct drive ignition on NIF  

E-Print Network (OSTI)

OMEGA ICF experiments and preparation for direct drive ignition on NIF R.L. McCrorya , R.E. Bahra) is investigating various theoretical aspects of a direct drive National Ignition Facility (NIF) ignition target equivalent to those planned for the NIF. The current experimental studies on OMEGA address the essential

325

Diagnosing implosion performance at the National Ignition Facility (NIF) by means of neutron spectrometry  

E-Print Network (OSTI)

Diagnosing implosion performance at the National Ignition Facility (NIF) by means of neutron.1088/0029-5515/53/4/043014 Diagnosing implosion performance at the National Ignition Facility (NIF) by means of neutron spectrometry J at the National Ignition Facility (NIF) provides essential information about the implosion performance. From

326

The Gated X-ray Detector for the National Ignition Facility  

Science Conference Proceedings (OSTI)

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 significant different from earlier generations of gated x-ray images due in parts to an innovative impendence 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 impendence reflections.

Oertel, J A; Barnes, C; Archuleta, T; Casper, L; Fatherley, V; Heinrichs, T; King, R; Landers, D; Lopez, F; Sanchez, P; Sandoval, G; Schrank, L; Walsh, P; Bell, P; Brown, M; Costa, R; Holder, J; Montalongo, S; Pederson, N

2006-05-18T23:59:59.000Z

327

Optimization of the process of plasma ignition of coal  

Science Conference Proceedings (OSTI)

Results are given of experimental and theoretical investigations of plasma ignition of coal as a result of its thermochemical preparation in application to the processes of firing up a boiler and stabilizing the flame combustion. The experimental test bed with a commercial-scale burner is used for determining the conditions of plasma ignition of low-reactivity high-ash anthracite depending on the concentration of coal in the air mixture and velocity of the latter. The calculations produce an equation (important from the standpoint of practical applications) for determining the energy expenditure for plasma ignition of coal depending on the basic process parameters. The tests reveal the difficulties arising in firing up a boiler with direct delivery of pulverized coal from the mill to furnace. A scheme is suggested, which enables one to reduce the energy expenditure for ignition of coal and improve the reliability of the process of firing up such a boiler. Results are given of calculation of plasma thermochemical preparation of coal under conditions of lower concentration of oxygen in the air mixture.

Peregudov, V.S. [Russian Academy of Sciences, Novosibirsk (Russian Federation)

2009-04-15T23:59:59.000Z

328

Inertial Confinement Fusion Ignition and High Yield Campaign  

E-Print Network (OSTI)

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: Provide mission need report for the proposed OMEGA Extended Performance project. · October 2002: NNSA

329

On Operational Power Reactor Regime and Ignited Spherical Tokamaks  

E-Print Network (OSTI)

, 2003 version of the "cold" magnetic "Fusion without ignition" in the next 35 years, the talk.-Pitersburg, St.-Pitersburg, RF % Insutute of Nuclear Fusion, RRC "Kurchatov Ins.", Moscow, RF & Vyoptics, Inc for magnetic fusion, OPRR requires a low recycling and wall-stabilized high- plasma. Because of the small

Zakharov, Leonid E.

330

National Ignition Facility faces an uncertain future David Kramer  

E-Print Network (OSTI)

at the National Ignition Facility to achieve a self-sustaining fusion reaction fell short. Now NIF stands to lose that were specified for NIF when the massive laser facility was ap- proved for construction in 1996. President Obama's fiscal year 2014 budget request calls for the end of NIF support for experiments proposed

331

CO/sub 2/-laser ignition of DAPP targets  

Science Conference Proceedings (OSTI)

A pulse derived by shuttering a CO/sub 2/ laser operating in the cw mode has been used to ignite a diallyl phthalate pyrotechnic (DAPP) material. Data from this work along with some data taken earlier, while operating the laser in the pulse mode, are presented. When operating in the cw mode, a pulse is mechanically chopped out of the beam and focussed onto the DAPP material. It was found that the shuttered cw mode of operation gives a more reproducible pulse and a more accurate determination of the incident energy than the pulse mode does. The pulse widths for threshold ignition (50% ignitions) at different power levels have been determined for 254 and 127 mm-focal-length lenses which were used to focus the beam on the target. It was also found that targets could be penetrated without ignition of the DAPP material. A 2.54 mm-thick DAPP target is penetrated by the laser beam if the energy per unit area exceeds 29 +1 J/mm/sup 2/. Based on this study, recommendations are given for improving the present test procedures used for DAPP material.

Brannon, P.J.

1981-07-01T23:59:59.000Z

332

Carbon dioxide emission during forest fires ignited by lightning  

E-Print Network (OSTI)

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.

Magdalena Pelc; Radoslaw Osuch

2009-03-31T23:59:59.000Z

333

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

Science Conference Proceedings (OSTI)

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.

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

2011-07-25T23:59:59.000Z

334

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

SciTech Connect

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.

None

2011-01-31T23:59:59.000Z

335

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

Science Conference Proceedings (OSTI)

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)

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

2010-11-15T23:59:59.000Z

336

The Development of a Detailed Chemical Kinetic Mechanism for Diisobutylene and Comparison to Shock Tube Ignition Times  

DOE Green Energy (OSTI)

There is much demand for chemical kinetic models to represent practical fuels such as gasoline, diesel and aviation fuel. These blended fuels contain hundreds of components whose identity and amounts are often unknown. A chemical kinetic mechanism that would represent the oxidation of all these species with accompanying chemical reactions is intractable with current computational capabilities, chemical knowledge and manpower resources. The use of surrogate fuels is an approach to make the development of chemical kinetic mechanisms for practical fuels tractable. A surrogate fuel model consists of a small number of fuel components that can be used to represent the practical fuel and still predict desired characteristics of the practical fuel. These desired fuel characteristics may include ignition behavior, burning velocity, fuel viscosity, fuel vaporization, and fuel emissions (carbon monoxide, hydrocarbons, soot and nitric oxides). Gasoline consists of many different classes of hydrocarbons including n-alkanes, alkenes, iso-alkanes, cycloalkanes, cycloalkenes, and aromatics. One approach is to use a fuel surrogate that has a single component from each class of hydrocarbon in gasoline so that the unique molecular structure of each class is represented. This approach may lead to reliable predictions of many of the combustion properties of the practical fuel. In order to obtain a fuel surrogate mechanism, detailed chemical kinetic mechanisms must be developed for each component in the surrogate. In this study, a detailed chemical kinetic mechanism is developed for diisobutylene, a fuel intended to represent alkenes in practical fuels such as gasoline, diesel, and aviation fuel. The fuel component diisobutylene usually consists of a mixture of two conjugate olefins of iso-octane: 1- or 2-pentene, 2,4,4-trimethyl. Diisobutylene has a similar molecular structure to iso-octane, so that its kinetics offers insight into the effect of including a double bond in the carbon skeletal structure of iso-octane. There are few previous studies on diisobutylene. Kaiser et al. [1] examined the exhaust emission from a production spark ignition engine with neat diisobutylene and with it mixed with gasoline. They found the exhaust emissions of diisobutylene to be similar to that of iso-octane. They saw a significant increase in the amount of 2-methyl-1,3-butadiene measured in the exhaust of the engine. They also found appreciable amount of propene in the exhaust, but could not explain the source of this product as they did others in terms of C-C bond beta scission of alkyl radicals. Risberg et al. [2] studied a number of fuel blends to evaluate their autoignition quality for use in a homogeneous charge compression ignition engine, using diisobutylene to represent olefins in one of their test fuels. In this study, experiments on the shock tube ignition of both isomers of diisobutylene will be described. Then, the development of a detailed chemical kinetic mechanism for the two isomers of diisobutylene will be discussed.

Metcalfe, W; Curran, H J; Simmie, J M; Pitz, W J; Westbrook, C K

2005-01-21T23:59:59.000Z

337

Spark Plasma Sintering of Tungsten and Tungsten-Ceria Powders  

Science Conference Proceedings (OSTI)

Opacified, Reinforced Aerogel for Thermal Insulation of Thermoelectric Generators and Other Advanced Energy Systems · Oxide Ceramic Materials for ...

338

Power Technologies Energy Data Book: Fourth Edition, Chapter...  

NLE Websites -- All DOE Office Websites (Extended Search)

two categories depending on the ignition source: spark ignition (SI), typically fueled by gasoline or natural gas; or compression ignition (CI), typically fueled by diesel oil. *...

339

Production of Sparks Via High Quality Laser Pulses Transmitted ...  

Fiber optic technology allows the laser to be located away from the extreme conditions inside the ... Fiber optic system allows diagnostic light to return for analysis.

340

ArcSafe® with Pulsed Arrested Spark Discharge  

NLE Websites -- All DOE Office Websites (Extended Search)

stress, aging electrical wiring systems, arc-physics, electrostatic dis- charge, and TEMPEST. R. Kevin Howard is a principle technologist with the Electromagnetic Technologies...

Note: This page contains sample records for the topic "ignition system spark" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Electrical Cable Testing by Pulse-Arrested Spark Discharge ...  

... useful to determine the location of defect sites in critical but inaccessible electrical cabling systems in aging aircraft, ships, nuclear power ...

342

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

DOE Green Energy (OSTI)

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.

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

2010-11-01T23:59:59.000Z

343

Modeling of high energy laser ignition of energetic materials  

SciTech Connect

We present a model for simulating high energy laser heating and ignition of confined energetic materials. The model considers the effect of irradiating a steel plate with long laser pulses and continuous lasers of several kilowatts and the thermal response of well-characterized high explosives for ignition. Since there is enough time for the thermal wave to propagate into the target and to create a region of hot spot in the high explosives, electron thermal diffusion of ultrashort (femto- and picosecond) lasing is ignored; instead, heat diffusion of absorbed laser energy in the solid target is modeled with thermal decomposition kinetic models of high explosives. Numerically simulated pulsed-laser heating of solid target and thermal explosion of cyclotrimethylenetrinitramine, triaminotrinitrobenzene, and octahydrotetranitrotetrazine are compared to experimental results. The experimental and numerical results are in good agreement.

Lee, Kyung-cheol; Kim, Ki-hong; Yoh, Jack J. [School of Mechanical and Aerospace Engineering, Seoul National University, Seoul, 151-742 (Korea, Republic of)

2008-04-15T23:59:59.000Z

344

Inertial Confinement Fusion and the National Ignition Facility (NIF)  

SciTech Connect

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.

Ross, P.

2012-08-29T23:59:59.000Z

345

Inertial fusion target development for ignition and energy  

SciTech Connect

The target needs of the next ICF experiments that will lead toward ignition and energy are different from those of today`s experiments. The future experiments on OMEGA Upgrade, GEKKO XII Upgrade, the National Ignition Facility and Megajoule will need large, precise, cryogenic targets. Development is needed on a number of aspects of these targets, including shell fabrication, characterization, cryogenic layering and target handling. However, coordinated R and D programs are in place and work is in process to carry out the needed development. It is vital to the success of inertial fusion that this work be sustained. Coordinated effort, like the National Cryogenic Target Program in the USA, will help make the development activities as efficient and effective as possible, and should be encouraged.

Schultz, K.R. [General Atomics, San Diego, CA (United States); Norimatsu, T. [Osaka Univ. (Japan). Inst. of Laser Engineering

1994-12-01T23:59:59.000Z

346

Production of Sparks via High-Quality Laser Pulses Through ...  

Fiber optic technology allows the laser to be located away from the ... The system allows light produced by the combus-tion to return from the cylinder for analysis.

347

Initial cone-in-shell fast-ignition experiments on OMEGA  

SciTech Connect

Fast ignition is a two-step inertial confinement fusion concept where megaelectron volt electrons ignite the compressed core of an imploded fuel capsule driven by a relatively low-implosion velocity. Initial surrogate cone-in-shell, fast-ignitor experiments using a highly shaped driver pulse to assemble a dense core in front of the cone tip were performed on the OMEGA/OMEGA EP Laser [T. R. Boehly et al., Opt. Commun. 133, 495 (1997); L. J. Waxer et al., Opt. Photonics News 16, 30 (2005)]. With optimal timing, the OMEGA EP pulse produced up to {approx}1.4 x 10{sup 7} additional neutrons which is a factor of {approx}4 more neutrons than without short-pulse heating. Shock-breakout measurements performed with the same targets and drive conditions demonstrate an intact cone tip at the time when the additional neutrons are produced. Velocity interferometer system for any reflector measurements show that x-rays from the shell's coronal plasma preheat the inner cone wall of thin-walled Au cones, while the thick-walled cones that are used in the integrated experiments are not affected by preheat.

Theobald, W.; Solodov, A. A.; Stoeckl, C.; Anderson, K. S.; Boehly, T. R.; Craxton, R. S.; Delettrez, J. A.; Dorrer, C.; Glebov, V. Yu.; Knauer, J. P.; Marshall, F. J.; Marshall, K. L.; Nilson, P. M.; Sangster, T. C.; Seka, W. [Laboratory for Laser Energetics and Fusion Science Center, 250 East River Road, Rochester, New York 14623-1299 (United States); Betti, R.; Meyerhofer, D. D. [Laboratory for Laser Energetics and Fusion Science Center, 250 East River Road, Rochester, New York 14623-1299 (United States); Departments of Mechanical Engineering and Physics, University of Rochester, Rochester, New York 14623 (United States); Frenje, J. A.; Sinenian, N. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Habara, H. [Graduate School of Engineering, Osaka University, Suita, 565-0871 Osaka (Japan)

2011-05-15T23:59:59.000Z

348

Electrically heated particulate filter enhanced ignition strategy  

DOE Patents (OSTI)

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.

Gonze, Eugene V; Paratore, Jr., Michael J

2012-10-23T23:59:59.000Z

349

National Ignition Facility monthly status report-January 2000  

SciTech Connect

The Project provides for the design, procurement, construction, assembly, installation, and acceptance testing of the National Ignition Facility (NIF), an experimental inertial confinement fusion facility intended to achieve controlled thermonuclear fusion in the laboratory by imploding a small capsule containing a mixture of the hydrogen isotopes deuterium and tritium. The NIF will be constructed at the Lawrence Livermore National Laboratory (LLNL), Livermore, California as determined by the Record of Decision made on December 19, 1996, as a part of the Stockpile Stewardship and Management Programmatic Environmental Impact Statement. Safety: On January 13, 2000, a worker received a back injury when a 42-in.-diameter duct fell during installation. He was taken by helicopter to the hospital and released on January 16, 2000. All work in the area was suspended, and the construction contractors went through a thorough safety review before work was started. A DOE occurrence report was filed. An independent LLNL Incident Analysis Team is reviewing the cause of the accident and will report out on March 1. A Project management review team is reviewing construction line management and safety support and will also report out on March 1. Several changes in work planning and site management have been incorporated to increase site safety. Technical Status: The general status of the technologies underlying the NIF Project remains satisfactory. The issues currently being addressed are (1) cleanliness for installation, assembly, and activation of the laser system by Systems Engineering; (2) laser glass--a second pilot run at one of the two commercial suppliers is ongoing; and (3) operational costs associated with final optics assembly (FOA) optics components--methods are being developed to mitigate 3 {omega}damage and resolve beam rotation issues. Schedule: The completion of the Title II design of laser equipment is now approximately 80% complete. The Beampath Infrastructure System is on the critical schedule path. The procurement strategy is being evaluated by commercial construction management and Architectural/Engineering (A/E) contractors with a report presented to a panel of independent experts, the Beampath Infrastructure System Implementation Review Committee Advisory Group who wrote a set of recommendations for proceeding with this critical path activity. In January, a briefing was given to DOE Oakland (OAK) Field Manager who then arranged briefings for the DOE OAK Procurement organization with the LLNL Procurement organization to review the proposed procurement strategies. The next step is to review the strategy with DOE Headquarters (HQ) procurement. The construction status of the Conventional Facilities at the end of January is 83% complete and is projected to finish within budget and on schedule. Cost: The NIF Project Total Project Cost (TPC) is $1.2B. The Project has obligated 73% of the TPC funds. The remaining contingency is $21.8M. Because of schedule delays and projected increases in the design, construction management, assembly, and installation of the system infrastructure, cost growth of the TPC is anticipated and will remain a major concern until the budget rebaseline process is completed.

Moses, E

2000-01-31T23:59:59.000Z

350

Future prospects for compression ignition fuel in California : fuel-related implications of possible pathways to mitigation of public health threats.  

SciTech Connect

This paper documents methods and results of an investigation of the options for and year 2010 consequences of possible new limitations on the use of diesel fuel in California, USA. California's Air Resources Board will undertake a risk management process to determine steps necessary to protect the health and safety of the public from carcinogenic species resident on diesel combustion exhaust particles. Environmental activist groups continue to call for the elimination of diesel fuel in California and other populous states. It is the declared intention of CARB not to ban or restrict diesel fuel, per se, at this time. Thus, two ''mid-course'' strategies now appear feasible: (1) Increased penetration of natural gas, LPG, and possibly lower alcohols into the transportation fuels market, to the extent that some Cl applications would revert to spark-ignition (SI) engines. (2) New specifications requiring diesel fuel reformulation based on more detailed investigation of exhaust products of individual diesel fuel constituents.

Eberhardt, J. J.; Rote, D. M.; Saricks, C. L.; Stodolsky, F.

1999-04-08T23:59:59.000Z

351

Influence of the molecular structure of biofuels on combustion in a compression ignition engine.  

E-Print Network (OSTI)

??This thesis presents an experimental study on the influence of the molecular structure of potential biofuels on combustion in a compression ignition engine. The molecular… (more)

Schönborn, A.

2009-01-01T23:59:59.000Z

352

Plasma ignition schemes for the SNS radio-frequency driven H- source  

E-Print Network (OSTI)

on the Spallation Neutron Source (SNS) Project,” EPAC ‘98,ignition schemes for the SNS radio-frequency driven H -the Spallation Neutron Source (SNS) is a cesiated, radio-

2001-01-01T23:59:59.000Z

353

Comparative study of heavy-duty engine operation with diesel fuel and ignition-improved methanol  

Science Conference Proceedings (OSTI)

Methanol can be made suitable for compression ignition engines by ignition-improving additives. The ignition improver demand can be minimized by increasing the compression ratio. The technical suitability of this fuel can be regarded as proven, since most of the problems connected with its use have been solved. Its economic viability, however, has still to be doubted. From an environmental point of view, ignition-improved methanol deserves great interest due to the total absence of soot in the exhaust and the considerably reduced NO/sub x/ emission.

Hardenberg, H.O.

1987-01-01T23:59:59.000Z

354

Implosion dynamics measurements at the National Ignition Facility  

Science Conference Proceedings (OSTI)

Measurements have been made of the in-flight dynamics of imploding capsules indirectly driven by laser energies of 1-1.7 MJ at the National Ignition Facility [Miller et al., Nucl. Fusion 44, 228 (2004)]. These experiments were part of the National Ignition Campaign [Landen et al., Phys. Plasmas 18, 051002 (2011)] to iteratively optimize the inputs required to achieve thermonuclear ignition in the laboratory. Using gated or streaked hard x-ray radiography, a suite of ablator performance parameters, including the time-resolved radius, velocity, mass, and thickness, have been determined throughout the acceleration history of surrogate gas-filled implosions. These measurements have been used to establish a dynamically consistent model of the ablative drive history and shell compressibility throughout the implosion trajectory. First results showed that the peak velocity of the original 1.3-MJ Ge-doped polymer (CH) point design using Au hohlraums reached only 75% of the required ignition velocity. Several capsule, hohlraum, and laser pulse changes were then implemented to improve this and other aspects of implosion performance and a dedicated effort was undertaken to test the sensitivity of the ablative drive to the rise time and length of the main laser pulse. Changing to Si rather than Ge-doped inner ablator layers and increasing the pulse length together raised peak velocity to 93% {+-} 5% of the ignition goal using a 1.5 MJ, 420 TW pulse. Further lengthening the pulse so that the laser remained on until the capsule reached 30% (rather than 60%-70%) of its initial radius, reduced the shell thickness and improved the final fuel {rho}R on companion shots with a cryogenic hydrogen fuel layer. Improved drive efficiency was observed using U rather than Au hohlraums, which was expected, and by slowing the rise time of laser pulse, which was not. The effect of changing the Si-dopant concentration and distribution, as well as the effect of using a larger initial shell thickness were also examined, both of which indicated that instabilities seeded at the ablation front are a significant source of hydrodynamic mix into the central hot spot. Additionally, a direct test of the surrogacy of cryogenic fuel layered versus gas-filled targets was performed. Together all these measurements have established the fundamental ablative-rocket relationship describing the dependence of implosion velocity on fractional ablator mass remaining. This curve shows a lower-than-expected ablator mass at a given velocity, making the capsule more susceptible to feedthrough of instabilities from the ablation front into the fuel and hot spot. This combination of low velocity and low ablator mass indicates that reaching ignition on the NIF will require >20 {mu}m ({approx}10%) thicker targets and laser powers at or beyond facility limits.

Hicks, D. G.; Meezan, N. B.; Dewald, E. L.; Mackinnon, A. J.; Callahan, D. A.; Doeppner, T.; Benedetti, L. R.; Bradley, D. K.; Celliers, P. M.; Clark, D. S.; Di Nicola, P.; Dixit, S. N.; Dzenitis, E. G.; Eggert, J. E.; Farley, D. R.; Glenn, S. M.; Glenzer, S. H.; Hamza, A. V.; Heeter, R. F.; Holder, J. P. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); and others

2012-12-15T23:59:59.000Z

355

Reducing Stickies in Recycle Mills with Spark Technology: Applications at Visy Paper Company  

Science Conference Proceedings (OSTI)

A full-scale trial run over a month at Visy Paper, Conyers, Georgia, showed that a single sparker unit placed in the stuff box could reduce stickie deposition on the dryer felts. The felts were also much easier to clean. While the benefits were clear, the trial was too short to allow quantification in view of all the other variables. The mill plans to lease a unit for a longer (3-plus month) trial. Kinetic work shows that both sonification and sparking generate hydroxyl radicals. Since both processes als...

2000-12-01T23:59:59.000Z

356

The First Experiments on the National Ignition Facility  

Science Conference Proceedings (OSTI)

A first set of laser-plasma interaction, hohlraum energetics and hydrodynamic experiments have been performed using the first 4 beams of the National Ignition Facility (NIF), in support of indirect drive Inertial Confinement Fusion (ICF) and High Energy Density Physics (HEDP). In parallel, a robust set of optical and x-ray spectrometers, interferometer, calorimeters and imagers have been activated. The experiments have been undertaken with laser powers and energies of up to 8 TW and 17 kJ in flattop and shaped 1-9 ns pulses focused with various beam smoothing options.

Landen, O L; Glenzer, S; Froula, D; Dewald, E; Suter, L J; Schneider, M; Hinkel, D; Fernandez, J; Kline, J; Goldman, S; Braun, D; Celliers, P; Moon, S; Robey, H; Lanier, N; Glendinning, G; Blue, B; Wilde, B; Jones, O; Schein, J; Divol, L; Kalantar, D; Campbell, K; Holder, J; MacDonald, J; Niemann, C; Mackinnon, A; Collins, R; Bradley, D; Eggert, J; Hicks, D; Gregori, G; Kirkwood, R; Young, B; Foster, J; Hansen, F; Perry, T; Munro, D; Baldis, H; Grim, G; Heeter, R; Hegelich, B; Montgomery, D; Rochau, G; Olson, R; Turner, R; Workman, J; Berger, R; Cohen, B; Kruer, W; Langdon, B; Langer, S; Meezan, N; Rose, H; Still, B; Williams, E; Dodd, E; Edwards, J; Monteil, M; Stevenson, M; Thomas, B; Coker, R; Magelssen, G; Rosen, P; Stry, P; Woods, D; Weber, S; Alvarez, S; Armstrong, G; Bahr, R; Bourgade, J; Bower, D; Celeste, J; Chrisp, M; Compton, S; Cox, J; Constantin, C; Costa, R; Duncan, J; Ellis, A; Emig, J; Gautier, C; Greenwood, A; Griffith, R; Holdner, F; Holtmeier, G; Hargrove, D; James, T; Kamperschroer, J; Kimbrough, J; Landon, M; Lee, D; Malone, R; May, M; Montelongo, S; Moody, J; Ng, E; Nikitin, A; Pellinen, D; Piston, K; Poole, M; Rekow, V; Rhodes, M; Shepherd, R; Shiromizu, S; Voloshin, D; Warrick, A; Watts, P; Weber, F; Young, P; Arnold, P; Atherton, L J; Bardsley, G; Bonanno, R; Borger, T; Bowers, M; Bryant, R; Buckman, S; Burkhart, S; Cooper, F; Dixit, S; Erbert, G; Eder, D; Ehrlich, B; Felker, B; Fornes, J; Frieders, G; Gardner, S; Gates, C; Gonzalez, M; Grace, S; Hall, T; Haynam, C; Heestand, G; Henesian, M; Hermann, M; Hermes, G; Huber, S; Jancaitis, K; Johnson, S; Kauffman, B; Kelleher, T; Kohut, T; Koniges, A E; Labiak, T; Latray, D; Lee, A; Lund, D; Mahavandi, S; Manes, K R; Marshall, C; McBride, J; McCarville, T; McGrew, L; Menapace, J; Mertens, E; Munro, D; Murray, J; Neumann, J; Newton, M; Opsahl, P; Padilla, E; Parham, T; Parrish, G; Petty, C; Polk, M; Powell, C; Reinbachs, I; Rinnert, R; Riordan, B; Ross, G; Robert, V; Tobin, M; Sailors, S; Saunders, R; Schmitt, M; Shaw, M; Singh, M; Spaeth, M; Stephens, A; Tietbohl, G; Tuck, J; Van Wonterghem, B; Vidal, R; Wegner, P; Whitman, P; Williams, K; Winward, K; Work, K

2005-11-11T23:59:59.000Z

357

The Role of Viscosity in TATB Hot Spot Ignition  

SciTech Connect

The role of dissipative effects, such as viscosity, in the ignition of high explosive pores is investigated using a coupled chemical, thermal, and hydrodynamic model. Chemical reactions are tracked with the Cheetah thermochemical code coupled to the ALE3D hydrodynamic code. We perform molecular dynamics simulations to determine the viscosity of liquid TATB. We also analyze shock wave experiments to obtain an estimate for the shock viscosity of TATB. Using the lower bound liquid-like viscosities, we find that the pore collapse is hydrodynamic in nature. Using the upper bound viscosity from shock wave experiments, we find that the pore collapse is closest to the viscous limit.

Fried, L E; Zepeda-Ruis, L; Howard, W M; Najjar, F; Reaugh, J E

2011-08-02T23:59:59.000Z

358

Overview of the Gamma Reaction History Diagnostic for the National Ignition Facility (NIF)  

Science Conference Proceedings (OSTI)

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 90º off-axis parabolic mirrors to relay Cherenkov light from a volume of pressurized gas. This nonimaging 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.

Malone, R M; Frogget, B C; Kaufman, M I; Tibbitts, A; Tunnell, T W; Evans, S C; Herrmann, H W; Kim, Y H; Mack, J M; Young, C S; McGillivray, K D; Palagi, M J

2010-09-01T23:59:59.000Z

359

ENERGY PARTITIONING, ENERGY COUPLING (EPEC) EXPERIMENTS AT THE NATIONAL IGNITION FACILITY  

Science Conference Proceedings (OSTI)

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.

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

360

Multi-Scale Modeling of Nano Aluminum Particle Ignition and Combustion  

E-Print Network (OSTI)

NEEM MURI Multi-Scale Modeling of Nano Aluminum Particle Ignition and Combustion Multi-Scale Modeling of Nano Aluminum Particle Ignition and Combustion Puneesh Puri and Vigor Yang The Pennsylvania Aluminum Particle Combustion · Aluminum oxide cap formed under the effect of surface tension · Oxidized

Yang, Vigor

Note: This page contains sample records for the topic "ignition system spark" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Ignition and Combustion of Fuel Pockets Moving in an Oxidizing Atmosphere  

E-Print Network (OSTI)

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

Heil, Matthias

362

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

E-Print Network (OSTI)

LES of an ignition sequence in a gas turbine engine M. Boileau a,, G. Staffelbach a , B. CuenotTurbomeca (SAFRAN group), Bordes, France Abstract Being able to ignite or reignite a gas turbine engine in a cold including 18 burners. This geometry corresponds to a real gas turbine chamber. Massively parallel computing

363

Wildfire ignition resistant home design(WIRHD) program: Full-scale testing and demonstration final report.  

SciTech Connect

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.

Quarles, Stephen, L.; Sindelar, Melissa

2011-12-13T23:59:59.000Z

364

Analytic criteria for shock ignition of fusion reactions in a central hot spot  

Science Conference Proceedings (OSTI)

Shock ignition is an inertial confinement fusion scheme where the ignition conditions are achieved in two steps. First, the DT shell is compressed at a low implosion velocity creating a central core at a low temperature and a high density. Then, a strong spherical converging shock is launched before the fuel stagnation time. It increases the central pressure and ignites the core. It is shown in this paper that this latter phase can be described analytically by using a self-similar solution to the equations of ideal hydrodynamics. A high and uniformly distributed pressure in the hot spot can be created thus providing favorable conditions for ignition. Analytic ignition criteria are obtained that relate the areal density of the compressed core with the shock velocity. The conclusions of the analytical model are confirmed in full hydrodynamic simulations.

Ribeyre, X.; Tikhonchuk, V. T.; Breil, J.; Lafon, M.; Le Bel, E. [Centre Lasers Intenses et Applications, Universite Bordeaux 1-CEA-CNRS, Talence 33405 (France)

2011-10-15T23:59:59.000Z

365

Direct Injection Compressed Ignition Diesel Automotive Technology Education GATE Program  

DOE Green Energy (OSTI)

The underlying goal of this project 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 technological barriers preventing the development and production of cost-effective high-efficiency vehicles for the US. market. Further, 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 technologies. Eight objectives were defined to accomplish this goal: (1) Develop an interdisciplinary internal combustion 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 curriculum. (4) Promote strong interaction with industry, 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 industrial sites. (8) Extend and Enhance the Graduate Experience.

Carl L. Anderson

2006-09-25T23:59:59.000Z

366

Engine ignition signal diagnosis with Wavelet Packet Transform and Multi-class Least Squares Support Vector Machines  

Science Conference Proceedings (OSTI)

Engine ignition pattern analysis is one of the trouble-diagnosis methods for automotive gasoline engines. Based on the waveform of the ignition pattern, the mechanic guesses what may be the potential malfunctioning parts of an engine with his/her experience ... Keywords: Automotive engine ignition pattern diagnosis, Multi-class Least Squares Support Vector Machines, Pattern classification, Wavelet Packet Transform

C. M. Vong; P. K. Wong

2011-07-01T23:59:59.000Z

367

Investigation of a rotary valving system with variable valve timing for internal combustion engines: Final technical report  

DOE Green Energy (OSTI)

The objective of the program was to provide a functional demonstration of the Hansen Rotary Valving System with Variable Valve timing (HRVS/VVT), capable of throttleless inlet charge control, as an alternative to conventional poppet-valves for use in spark ignited internal combustion engines. The goal of this new technology is to secure benefits in fuel economy, broadened torque band, vibration reduction, and overhaul accessibility. Additionally, use of the variable valve timing capability to vary the effective compression ratio is expected to improve multi-fuel tolerance and efficiency. Efforts directed at the design of HRVS components proved to be far more extensive than had been anticipated, ultimately requiring that proof-trial design/development work be performed. Although both time and funds were exhausted before optical or ion-probe types of in-cylinder investigation could be undertaken, a great deal of laboratory data was acquired during the course of the design/development work. This laboratory data is the basis for the information presented in this Final Report.

Cross, P.C.; Hansen, C.N.

1994-11-18T23:59:59.000Z

368

Spark of Life We are all familiar with the idea that machines are powered by electricity, but perhaps not so  

E-Print Network (OSTI)

Spark of Life We are all familiar with the idea that machines are powered by electricity of the body electric, showing how, from before conception to the last breath we draw, electrical signals a heart attack? Why does an electric eel not shock itself? Can someone really die of fright? Why does

Rambaut, Andrew

369

Kinetics of Potassium Desorption in Soil using Miscible Displacement1 D. L. SPARKS, L. W. ZELAZNY, AND D. C. MARTENSZ  

E-Print Network (OSTI)

Kinetics of Potassium Desorption in Soil using Miscible Displacement1 D. L. SPARKS, L. W. ZELAZNY, and B22t horizons of two Dothan (Plinthic Pa- leudults) soils. Aluminum- and calcium- saturated samples was subsequently de- sorbed suggesting K adsorption-desorption in the Dothan soils was reversible. A linear

Sparks, Donald L.

370

Observations and Modeling of Long Negative Laboratory Discharges: Identifying the Physics Important to an Electrical Spark in Air  

SciTech Connect

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.

Biagi, C J; Uman, M A

2011-12-13T23:59:59.000Z

371

Report on ignitability testing of flammable gasses in a core sampling drill string  

DOE Green Energy (OSTI)

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.

Witwer, K.S., Westinghouse Hanford

1996-12-01T23:59:59.000Z

372

Fuel Effects on Ignition and Their Impact on Advanced Combustion Engines (Poster)  

DOE Green Energy (OSTI)

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.

Taylor, J.; Li, H.; Neill, S.

2006-08-01T23:59:59.000Z

373

Laser Inertial Fusion-based Energy: Neutronic Design Aspects of a Hybrid Fusion-Fission Nuclear Energy System  

E-Print Network (OSTI)

Example of NIF fusion target hohlraum with multiple beamsimilar to those used on NIF. . . . . Overview of LFFHNES Nuclear Energy System NIF National Ignition Facility ODS

Kramer, Kevin James

2010-01-01T23:59:59.000Z

374

Application of pulse spark discharges for scale prevention and continuous filtration methods in coal-fired power plant Oct. 1, 2008 Â… Sept. 30, 2011  

NLE Websites -- All DOE Office Websites (Extended Search)

Drexel University Drexel University Y. Cho, A. Fridman, and A. Starikovskii Oct. 28, 2008 Application of pulse spark discharges for scale prevention and continuous filtration methods in coal-fired power plant U.S. DEPARTMENT OF ENERGY National Energy Technology Laboratory New Scale-Prevention Technology Use electrical pulse spark discharges in water to precipitate dissolved mineral ions. Remove them using a self-cleaning filter from cooling water. Specific objectives of the proposed work 1. Determine whether the spark discharge can promote the precipitation of mineral ions in cooling water. 2. Determine whether the proposed technology can increase the COC through a continuous precipitation of calcium ions

375

U  

NLE Websites -- All DOE Office Websites (Extended Search)

4, 2008 4, 2008 Dustin McIntyre, a mechanical engineer at the U.S. Department of Energy's National Energy Technology Laboratory (NETL), is one of the inventors of a laser spark distribution and ignition system developed at NETL which has recently been issued a patent. f al electrical spark plugs. McIntyre, a resident of Morgantown, WV, received his BS degrees in electrical engineering and computer engineering and MS and PhD in mechanical engineering from West Virginia University in Morgantown, WV. Producing a high peak power laser spark from a single low power pulse, this laser spark distribution and ignition system has application in natural gas-fueled reciprocating engines, turbine combustors, explosives, and laser- induced breakdown spectroscopy diagnostic sensors. The laser spark plug

376

U  

NLE Websites -- All DOE Office Websites (Extended Search)

11, 2008 11, 2008 Steven Woodruff, a research chemist at the U.S. Department of Energy's National Energy Technology Laboratory (NETL), is one of the inventors of a laser spark distribution and ignition system developed at NETL which has recently been issued a patent. Woodruff, a resident of Morgantown, WV, received his BS from the University of Michigan, Dearborn Campus, and MS and PhD in chemistry from the University of Michigan, Ann Arbor. NETL has previously demonstrated that laser spark ignition can be used to reduce Nitrogen Oxide emissions and improve performance of Natural Gas Fired engines. Laser sparks provide more spark energy than conventional electric spark systems which enables engine operation at leaner conditions resulting in lower emissions. The missing component

377

NIF achieves record laser energy in pursuit of fusion ignition | National  

NLE Websites -- All DOE Office Websites (Extended Search)

achieves record laser energy in pursuit of fusion ignition | National achieves record laser energy in pursuit of fusion ignition | National Nuclear Security Administration Our Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear Navy Emergency Response Recapitalizing Our Infrastructure Continuing Management Reform Countering Nuclear Terrorism About Us Our Programs Our History Who We Are Our Leadership Our Locations Budget Our Operations Media Room Congressional Testimony Fact Sheets Newsletters Press Releases Speeches Events Social Media Video Gallery Photo Gallery NNSA Archive Federal Employment Apply for Our Jobs Our Jobs Working at NNSA Blog Home > NNSA Blog > NIF achieves record laser energy in pursuit ... NIF achieves record laser energy in pursuit of fusion ignition Posted By Office of Public Affairs NNSA Blog The NNSA's National Ignition Facility (NIF) surpassed a critical

378

Analytical and numerical models of uranium ignition assisted by hydride formation  

DOE Green Energy (OSTI)

Analytical and numerical models of uranium ignition assisted by the oxidation of uranium hydride are described. The models were developed to demonstrate that ignition of large uranium ingots could not occur as a result of possible hydride formation during storage. The thermodynamics-based analytical model predicted an overall 17 C temperature rise of the ingot due to hydride oxidation upon opening of the storage can in air. The numerical model predicted locally higher temperature increases at the surface; the transient temperature increase quickly dissipated. The numerical model was further used to determine conditions for which hydride oxidation does lead to ignition of uranium metal. Room temperature ignition only occurs for high hydride fractions in the nominally oxide reaction product and high specific surface areas of the uranium metal.

Totemeier, T.C.; Hayes, S.L. [Argonne National Lab., Idaho Falls, ID (United States). Engineering Div.

1996-05-01T23:59:59.000Z

379

Method and apparatus for igniting an in situ oil shale retort  

DOE Patents (OSTI)

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.

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

380

Effects of natural gas composition on ignition delay under diesel conditions  

DOE Green Energy (OSTI)

Effects of variations in natural gas composition on autoignition of natural gas under direct-injection (DI) diesel engine conditions were studied experimentally in a constant-volume combustion vessel and computationally using a chemical kinetic model. Four fuel blends were investigated: pure methane, a capacity weighted mean natural gas, a high ethane content natural gas, and a natural gas with added propane typical of peak shaving conditions. Experimentally measured ignition delays were longest for pure methane and became progressively shorter as ethane and propane concentrations increased. At conditions characteristic of a DI compression ignition natural gas engine at Top Dead Center (CR=23:1, p = 6.8 MPa, T = 1150K), measured ignition delays for the four fuels varied from 1.8 ms for the peak shaving and high ethane gases to 2.7 ms for pure methane. Numerically predicted variations in ignition delay as a function of natural gas composition agreed with these measurements.

Naber, J.D.; Siebers, D.L. [Sandia National Labs., Livermore, CA (United States); Di Julio, S.S. [California State Univ., Northridge, CA (United States). Dept. of Mechanical Engineering; Westbrook, C.K. [Lawrence Livermore National Lab., CA (United States)

1993-12-03T23:59:59.000Z

Note: This page contains sample records for the topic "ignition system spark" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Tungsten bridge for the low energy ignition of explosive and energetic materials  

DOE Patents (OSTI)

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.

Benson, David A. (Albuquerque, NM); Bickes, Jr., Robert W. (Albuquerque, NM); Blewer, Robert S. (Albuquerque, NM)

1990-01-01T23:59:59.000Z

382

Tungsten bridge for the low energy ignition of explosive and energetic materials  

DOE Patents (OSTI)

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.

Benson, D.A.; Bickes, R.W. Jr.; Blewer, R.S.

1990-12-11T23:59:59.000Z

383

Extension of the high load limit in the Homogeneous Charge Compression Ignition engine  

E-Print Network (OSTI)

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 ...

Scaringe, Robert J. (Robert Joseph)

2009-01-01T23:59:59.000Z

384

Effect of NO on extinction and re-ignition of vortex-perturbed hydrogen flames.  

DOE Green Energy (OSTI)

The catalytic effect of nitric oxide (NO) on the dynamics of extinction and re-ignition of a vortex-perturbed non-premixed hydrogen-air flame is studied in a counterflow burner. A diffusion flame is established with counterflowing streams of nitrogen-diluted hydrogen at ambient temperature and air heated to a range of temperatures that brackets the auto-ignition temperature. Localized extinction is induced by impulsively driving a fuel-side toroidal vortex into the steady flame, and the recovery of the extinguished region is monitored by planar laser-induced fluorescence (PLIF) of the hydroxyl radical (OH). The dynamics of flame recovery depend on the air temperature and fuel concentration, and four different recovery modes are identified. These modes involve combinations of edge-flame propagation and the expansion of an auto-ignition kernel that forms within the extinguished region. The addition of a small amount of NO significantly alters the re-ignition process by shifting the balance between chain-termination and chain-propagation reactions to enhance auto-ignition. The ignition enhancement by this catalytic effect causes a shift in the conditions that govern the recovery modes. In addition, the effects of NO concentration and vortex strength on the flame recovery are examined. Direct numerical simulations of the flame-vortex interaction with and without NO doping show how the small amount of OH produced by NO-catalyzed reactions has a significant impact on the development of an auto-ignition kernel. This joint experimental and numerical study provides detailed insight into the interaction between transient flows and ignition processes.

Yoo, Chun Sang; Chen, Jacqueline H.; Frank, Jonathan H.; Lee, Uen Do (KITECH, Cheonan, Chungnam, South Korea)

2009-01-01T23:59:59.000Z

385

Fire Events Database and Generic Ignition Frequency Model for U.S. Nuclear Power Plants  

Science Conference Proceedings (OSTI)

This report contains a revision of the EPRI Fire Events Database for U.S. Nuclear Power Plants last published in EPRI Report 1000894 in October 2000. This report also contains a revision of the generic fire ignition frequency models that were published in NSAC-178L, "Fire Events Database of U.S. Nuclear Power Plants" (January 1993) and EPRI TR-105929, "Fire Ignition Frequency Model at Shutdown for U.S. Nuclear Power Plants" (December 1995).

2001-11-09T23:59:59.000Z

386

Jet fuel ignition delay times: Shock tube experiments over wide conditions and surrogate model predictions  

Science Conference Proceedings (OSTI)

Ignition delay times were measured for gas-phase jet fuel (Jet-A and JP-8) in air behind reflected shock waves in a heated high-pressure shock tube. Initial reflected shock conditions were as follows: temperatures of 715-1229 K, pressures of 17-51 atm, equivalence ratios of 0.5 and 1, and oxygen concentrations of 10 and 21% in synthetic air. Ignition delay times were measured using sidewall pressure and OH* emission at 306 nm. Longer ignition delay times at low temperatures (715-850 K) were accessed by utilizing driver-gas tailoring methods. Also presented is a review of previous ignition delay time measurements of kerosene-based fuels and recent work on surrogate fuel and kinetic mechanism development. To our knowledge, we report the first gas-phase shock tube ignition delay time data for JP-8, and our measurements for Jet-A are for a broader range of conditions than previously available. Our results have very low scatter and are in excellent agreement with the limited previous shock tube data for Jet-A. Although JP-8 and Jet-A have slightly different compositions, their ignition delay times are very similar. A simple 1/P dependence was found for ignition delay times from 874 to 1220 K for the pressure range studied for both fuels. Ignition delay time variations with equivalence ratio and oxygen concentration were also investigated. The new experimental results were compared with predictions of several kinetic mechanisms, using different jet fuel surrogate mixtures. (author)

Vasu, Subith S.; Davidson, David F.; Hanson, Ronald K. [Mechanical Engineering Department, Stanford University, Stanford, CA 94305 (United States)

2008-01-15T23:59:59.000Z

387

On the Fielding of a High Gain, Shock-Ignited Target on the National Ignitiion Facility in the Near Term  

SciTech Connect

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.

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

388

Cryogenic thermonuclear fuel implosions on the National Ignition Facility  

Science Conference Proceedings (OSTI)

The first inertial confinement fusion implosion experiments with equimolar deuterium-tritium thermonuclear fuel have been performed on the National Ignition Facility. These experiments use 0.17 mg of fuel with the potential for ignition and significant fusion yield conditions. The thermonuclear fuel has been fielded as a cryogenic layer on the inside of a spherical plastic capsule that is mounted in the center of a cylindrical gold hohlraum. Heating the hohlraum with 192 laser beams for a total laser energy of 1.6 MJ produces a soft x-ray field with 300 eV temperature. The ablation pressure produced by the radiation field compresses the initially 2.2-mm diameter capsule by a factor of 30 to a spherical dense fuel shell that surrounds a central hot-spot plasma of 50 {mu}m diameter. While an extensive set of x-ray and neutron diagnostics has been applied to characterize hot spot formation from the x-ray emission and 14.1 MeV deuterium-tritium primary fusion neutrons, thermonuclear fuel assembly is studied by measuring the down-scattered neutrons with energies in the range of 10 to 12 MeV. X-ray and neutron imaging of the compressed core and fuel indicate a fuel thickness of (14 {+-} 3) {mu}m, which combined with magnetic recoil spectrometer measurements of the fuel areal density of (1 {+-} 0.09) g cm{sup -2} result in fuel densities approaching 600 g cm{sup -3}. The fuel surrounds a hot-spot plasma with average ion temperatures of (3.5 {+-} 0.1) keV that is measured with neutron time of flight spectra. The hot-spot plasma produces a total fusion neutron yield of 10{sup 15} that is measured with the magnetic recoil spectrometer and nuclear activation diagnostics that indicate a 14.1 MeV yield of (7.5{+-}0.1) Multiplication-Sign 10{sup 14} which is 70% to 75% of the total fusion yield due to the high areal density. Gamma ray measurements provide the duration of nuclear activity of (170 {+-} 30) ps. These indirect-drive implosions result in the highest areal densities and neutron yields achieved on laser facilities to date. This achievement is the result of the first hohlraum and capsule tuning experiments where the stagnation pressures have been systematically increased by more than a factor of 10 by fielding low-entropy implosions through the control of radiation symmetry, small hot electron production, and proper shock timing. The stagnation pressure is above 100 Gbars resulting in high Lawson-type confinement parameters of P{tau} Asymptotically-Equal-To 10 atm s. Comparisons with radiation-hydrodynamic simulations indicate that the pressure is within a factor of three required for reaching ignition and high yield. This will be the focus of future higher-velocity implosions that will employ additional optimizations of hohlraum, capsule and laser pulse shape conditions.

Glenzer, S. H.; Callahan, D. A.; MacKinnon, A. J.; Alger, E. T.; Berger, R. L.; Bernstein, L. A.; Bleuel, D. L.; Bradley, D. K.; Burkhart, S. C.; Burr, R.; Caggiano, J. A.; Castro, C.; Choate, C.; Clark, D. S.; Celliers, P.; Cerjan, C. J.; Collins, G. W.; Dewald, E. L.; DiNicola, P.; DiNicola, J. M. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); and others

2012-05-15T23:59:59.000Z

389

HIGH-RESOLUTION SIMULATIONS OF CONVECTION PRECEDING IGNITION IN TYPE Ia SUPERNOVAE USING ADAPTIVE MESH REFINEMENT  

E-Print Network (OSTI)

We extend our previous three-dimensional, full-star simulations of the final hours of convection preceding ignition in Type Ia supernovae to higher resolution using the adaptive mesh refinement capability of our low Mach number code, MAESTRO. We report the statistics of the ignition of the first flame at an effective 4.34 km resolution and general flow field properties at an effective 2.17 km resolution. We find that off-center ignition is likely, with radius of 50 km most favored and a likely range of 40–75 km. This is consistent with our previous coarser (8.68 km resolution) simulations, implying that we have achieved sufficient resolution in our determination of likely ignition radii. The dynamics of the last few hot spots preceding ignition suggest that a multiple ignition scenario is not likely. With improved resolution, we can more clearly see the general flow pattern in the convective region, characterized by a strong outward plume with a lower speed recirculation. We show that the convective core is turbulent with a Kolmogorov spectrum and has a lower turbulent intensity and larger integral length scale than previously thought (on the order of 16 km s?1 and 200 km, respectively), and we discuss the potential consequences for the first flames. Key words: convection – hydrodynamics – methods: numerical – nuclear reactions, nucleosynthesis, abundances – supernovae: general – white dwarfs Online-only material: color figures 1.

A. Nonaka; A. J. Aspden; M. Zingale; A. S. Almgren; J. B. Bell; S. E. Woosley

2012-01-01T23:59:59.000Z

390

Capsule implosion optimization during the indirect-drive National Ignition Campaign  

Science Conference Proceedings (OSTI)

Capsule performance optimization campaigns will be conducted at the National Ignition Facility [G. H. Miller, E. I. Moses, and C. R. Wuest, Nucl. Fusion 44, 228 (2004)] to substantially increase the probability of ignition. The campaigns will experimentally correct for residual uncertainties in the implosion and hohlraum physics used in our radiation-hydrodynamic computational models using a variety of ignition capsule surrogates before proceeding to cryogenic-layered implosions and ignition experiments. The quantitative goals and technique options and down selections for the tuning campaigns are first explained. The computationally derived sensitivities to key laser and target parameters are compared to simple analytic models to gain further insight into the physics of the tuning techniques. The results of the validation of the tuning techniques at the OMEGA facility [J. M. Soures et al., Phys. Plasmas 3, 2108 (1996)] under scaled hohlraum and capsule conditions relevant to the ignition design are shown to meet the required sensitivity and accuracy. A roll-up of all expected random and systematic uncertainties in setting the key ignition laser and target parameters due to residual measurement, calibration, cross-coupling, surrogacy, and scale-up errors has been derived that meets the required budget. Finally, we show how the tuning precision will be improved after a number of shots and iterations to meet an acceptable level of residual uncertainty.

Landen, O. L.; Edwards, J.; Haan, S. W.; Robey, H. F.; Milovich, J.; Spears, B. K.; Weber, S. V.; Clark, D. S.; Lindl, J. D.; MacGowan, B. J.; Moses, E. I.; Atherton, J.; Amendt, P. A.; Bradley, D. K.; Braun, D. G.; Callahan, D. A.; Celliers, P. M.; Collins, G. W.; Dewald, E. L.; Divol, L. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

2011-05-15T23:59:59.000Z

391

Fielding of an Imaging VISAR Diagnostic at the National Ignition Facility (NIF)  

Science Conference Proceedings (OSTI)

The National Ignition Facility (NIF) requires diagnostics to analyze high-energy density physics experiments. As a core NIF early light diagnostic, this system measures shock velocities, shock breakout times, and shock emission of targets with sizes from 1 to 5 mm. A 659.5 nm VISAR probe laser illuminates the target. An 8-inch-diameter fused silica triplet lens collects light at f/3 inside the 33-foot-diameter vacuum chamber. The optical relay sends the image out an equatorial port, through a 2-inch-thick vacuum window, and into two VISAR (Velocity Interferometer System for Any Reflector) interferometers. Both streak cameras and CCD cameras record the images. Total track is 75 feet. The front end of the optical relay can be temporarily removed from the equatorial port, allowing for other experimenters to use that port. The first triplet can be no closer than 500 mm from the target chamber center and is protected from debris by a blast window that is replaced after every event. Along with special coatings on the mirrors, cutoff filters reject the NIF drive laser wavelengths and pass a band of wavelengths for VISAR, for passive shock breakout light, or for thermal imaging light (bypassing the interferometers). Finite Element Analysis was performed on all mounting structures. All optical lenses are on kinematic mounts, so that the pointing accuracy of the optical axis can be checked. A two-color laser alignment scheme is discussed.

Malone, R; Bower, J; Capelle, G; Celeste, J; Celliers, P; Frogget, B C; Guyton, R L; Kauffman, M; Lare, G; Lee, T; MacGowan, B; Montelongo, S; Thomas, T; Tunnell, T; Watts, P

2004-06-30T23:59:59.000Z

392

Frequency converter development for the National Ignition Facility  

SciTech Connect

The design of the National Ignition Facility (NIF) incorporates a type I/type II third harmonic generator to convert the 1.053-{micro}m fundamental wavelength of the laser amplifier to a wavelength of 0.351 {micro}m for target irradiation. To understand and control the tolerances in the converter design, we have developed a comprehensive error budget that accounts for effects that are known to influence conversion efficiency, including variations in amplitude and phase of the incident laser pulse, temporal bandwidth of the incident laser pulse, crystal surface figure and bulk non-uniformities, angular alignment errors, Fresnel losses, polarization errors and crystal temperature variations. The error budget provides specifications for the detailed design of the NIF final optics assembly (FOA) and the fabrication of optical components. Validation is accomplished through both modeling and measurement, including full-scale Beamlet tests of a 37-cm aperture frequency converter in a NIF prototype final optics cell. The prototype cell incorporates full-perimeter clamping to support the crystals, and resides in a vacuum environment as per the NIF design.

Auerbach, J M; Barker, C E; Burkhart, S C; Couture, S A; DeYoreo, J J; Hackel, L A; Hibbard, R L; Liou, L W; Norton, M A; Wegner, P J; Whitman, P A

1998-10-30T23:59:59.000Z

393

Ignition and Growth Modeling of LX-17 Hockey Puck Experiments  

Science Conference Proceedings (OSTI)

Detonating solid plastic bonded explosives (PBX) formulated with the insensitive molecule triaminotrinitrobenzene (TATB) exhibit measurable reaction zone lengths, curved shock fronts, and regions of failing chemical reaction at abrupt changes in the charge geometry. A recent set of ''hockey puck'' experiments measured the breakout times of diverging detonation waves in ambient temperature LX-17 (92.5 % TATB plus 7.5% Kel-F binder) and the breakout times at the lower surfaces of 15 mm thick LX-17 discs placed below the detonator-booster plane. The LX-17 detonation waves in these discs grow outward from the initial wave leaving regions of unreacted or partially reacted TATB in the corners of these charges. This new experimental data is accurately simulated for the first time using the Ignition and Growth reactive flow model for LX-17, which is normalized to a great deal of detonation reaction zone, failure diameter and diverging detonation data. A pressure cubed dependence for the main growth of reaction rate yields excellent agreement with experiment, while a pressure squared rate diverges too quickly and a pressure quadrupled rate diverges too slowly in the LX-17 below the booster equatorial plane.

Tarver, C M

2004-04-19T23:59:59.000Z

394

Measurement of the propagation velocity of single plasma channels in a spark chamber for particle track detection  

SciTech Connect

The velocity of growth of single tracks in a spark chamber is described. It is shown thai in the pressure range 300 < p < 760 torr the tracks propagate with the same velocity to the anode and cathode provided that E/p remains below an experimentally determined value. A rise of this value causes an asymmetry, which makes the chamber no longer suited for the track localization of ionizing particles. (GE)

Timm, U.

1972-01-01T23:59:59.000Z

395

Formative time of breakdown modeled for the ignition of air and n-butane mixtures using effective ionization coefficients  

Science Conference Proceedings (OSTI)

It is shown that simulations of ignition by electric arc discharge in n-butane and air mixtures have interesting features, which deviate from results obtained by simple extension of calculations based on methanelike fuels. In particular, it is demonstrated that lowering the temperature of the n-butane-air mixture before ignition under certain conditions will actually decrease the ignition stage time as well as the required electric field.

Kudryavtsev, A. A.; Popugaev, S. D. [St. Petersburg State University, St. Petersburg 198904 (Russian Federation); Demidov, V. I. [Department of Physics, West Virginia University, Morgantown, West Virginia 26506 (United States); Adams, S. F. [Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States); Jiao, C. Q. [ISSI Inc., Dayton, Ohio 45440-3638 (United States)

2008-12-15T23:59:59.000Z

396

Two-stage Ignition as an Indicator of Low Temperature Combustion in a Late Injection Pre-mixed Compression Ignition Control Strategy  

E-Print Network (OSTI)

Internal combustion engines have dealt with increasingly restricted emissions requirements. After-treatment devices are successful in bringing emissions into compliance, but in-cylinder combustion control can reduce their burden by reducing engine out emissions. For example, oxides of nitrogen (NOx) are diesel combustion exhaust species that are notoriously difficult to remove by after-treatment. In-cylinder conditions can be controlled for low levels of NOx, but this produces high levels of soot potentially leading to increased particulate matter (PM). The simultaneous reduction of NOx and PM can be realized through a combustion process known as low temperature combustion (LTC). In this study, the typical definition of LTC as the defeat of the inverse relationship between soot and NOx is not applicable as a return to the soot-NOx tradeoff is observed with increasing exhaust gas recirculation (EGR). It is postulated that this effect is the result of an increase in the hot ignition equivalence ratio, moving the combustion event into a slightly higher soot formation region. This is important because a simple emissions based definition of LTC is no longer helpful. In this study, the manifestation of LTC in the calculated heat release profile is investigated. The conditions classified as LTC undergo a two-stage ignition process. Two-stage ignition is characterized by an initial cool-flame reaction followed by typical hot ignition. In traditional combustion conditions, the ignition is fast enough that a cool-flame is not observed. By controlling initial conditions (pressure, temperature, and composition), the creation and duration of the cool-flame event is predictable. Further, the effect that injection timing and the exhaust gas recirculation level have on the controlling factors of the cool-flame reaction is well correlated to the duration of the cool-flame event. These two results allow the postulation that the presence of a sufficiently long cool-flame reaction indicates a combustion event that can be classified as low temperature combustion. A potential method for identifying low temperature combustion events using only the rate of heat release profile is theorized. This study employed high levels of EGR and late injection timing to realize the LTC mode of ordinary petroleum diesel fuel. Under these conditions, and based on a 90 percent reduction in nitric oxide and no increase in smoke output relative to the chosen baseline condition, a two part criteria is developed that identifies the LTC classified conditions. The criteria are as follow: the combustion event of conventional petroleum diesel fuel must show a two-stage ignition process; the first stage (cool-flame reaction) must consume at least 2 percent of the normalized fuel energy before the hot ignition commences.

Bittle, Joshua

2010-12-01T23:59:59.000Z

397

STATEMENT OF CONSIDERATIONS REQUEST BY GENERAL MOTORS CORPORATION...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

for the performance of work entitled, "Development of High Efficiency Clean Combustion Engine Designs for Spark Ignition and Compression Ignition Internal Combustion...

398

Electron beam and plasma modes of a channel spark discharge operation  

SciTech Connect

Parameters of a modified pulsed channel spark discharge (CSD), operating at a repetition rate up to 100 Hz at Ar gas pressures of 10{sup -3} and 10{sup -4} Torr and of the generated electron beam, were studied using different electrical, optical, and x-ray diagnostics. It was shown that efficient (up to approx74%) transfer of the initially stored energy to the energetic electron beam is realized only at the pressure of 10{sup -4} Torr. Conversely, at the pressure of 10{sup -3} Torr, less than 10% of the stored energy is acquired by the energetic electrons. It was found that the energetic electron beam generation is limited by the expansion of the cathode and anode plasmas and by the formation of plasma inside the gap between the CSD capillary output and the anode. It was also found that the plasma, which acquires the hollow cathode potential, is already formed at the beginning of the CSD operation inside the capillary, and the electron emission occurs from the capillary output plasma boundary. Finally, it was shown that the electron beam energy spectrum differs significantly from the energy spectrum, which one may expect in the case of the planar diode operation.

Gleizer, S.; Yarmolich, D.; Felsteiner, J.; Krasik, Ya. E. [Department of Physics, Technion, 32000 Haifa (Israel); Nozar, P. [Istituto per lo Studio dei Materiali Nanostrutturati, 40129 Bologna (Italy); Taliani, C. [Organic Spintronics, Srl, 40129 Bologna (Italy)

2009-10-01T23:59:59.000Z

399

Target Diagnostic Instrument-Based Controls Framework for the National Ignition Facility (NIF)  

Science Conference Proceedings (OSTI)

The extreme physics of targets shocked by NIF's 192-beam laser are observed by a diverse suite of diagnostics including optical backscatter, time-integrated and gated X-ray sensors, and laser velocity interferometry. Diagnostics to diagnose fusion ignition implosion and neutron emissions are being planned. Many diagnostics will be developed by collaborators at other sites, but ad hoc controls could lead to unreliable and costly operations. An instrument-based controls (I-BC) framework for both hardware and software facilitates development and eases integration. Each complex diagnostic typically uses an ensemble of electronic instruments attached to sensors, digitizers, cameras, and other devices. In the I-BC architecture each instrument is interfaced to a low-cost Windows XP processor and Java application. Each instrument is aggregated with others as needed in the supervisory system to form an integrated diagnostic. The Java framework provides data management, control services and operator GUI generation. I-BCs are reusable by replication and reconfiguration for specific diagnostics in XML. Advantages include minimal application code, easy testing, and better reliability. Collaborators save costs by assembling diagnostics with existing I-BCs. This paper discusses target diagnostic instrumentation used on NIF and presents the I-BC architecture and framework.

Shelton, R T; O'Brien, D W; Kamperschroer, J H; Nelson, J R

2007-10-03T23:59:59.000Z

400

Radiochemistry: A versatile diagnostic for the NIF ignition campaign  

Science Conference Proceedings (OSTI)

The purpose of this paper is to provide quick, clear, concise information about radiochemical diagnostics for the NIF program. Radiochemistry is perhaps the most versatile, flexible and dynamic of all nuclear diagnostics because it provides quantitative data on multiple capsule performance parameters such as mix, asymmetry of implosion, shell and fuel {rho}R, yield, neutron spectral information, high energy neutron information, fill tube jets, charged particle stopping, and the fission yield of the hohlraum by employing a variety of nuclear reactions on materials either present naturally in the capsule or specifically doped into the capsule. The choice and location of the doped material, together with the specific nuclear reaction used to produce a measurable product nuclide or ratio of nuclides, provides significant diagnostic information on the performance of the capsule during the experiment. The nature of the experiment, design of the capsule including fuel(s), and desired diagnostic information would dictate the radiochemical dopants used on any given shot--not all reactions would be possible nor monitored on any given experiment. Some of this diagnostic information is obtainable with other diagnostics, for example, the neutron yield is measured using Cu-activation pucks or nTOF. The unique niche of radiochemistry, for which few other measurements are currently planned, is the quantification of ablator/fuel mix. This diagnostic can supply complementary information on ablator {rho}R, asymmetry and unique information on mix--three of the four important concerns of the ignition campaign. This paper will not discuss the additional nuclear chemistry and physics possible by utilizing radiochemistry collection and similar nuclear reactions.

Stoyer, M A; Cerjan, C J; Moody, K J; Hoffman, R D; Bernstein, L A; Shaughnessy, D A

2008-06-17T23:59:59.000Z

Note: This page contains sample records for the topic "ignition system spark" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Gasoline surrogate modeling of gasoline ignition in a rapid compression machine and comparison to experiments  

DOE Green Energy (OSTI)

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.

Mehl, M; Kukkadapu, G; Kumar, K; Sarathy, S M; Pitz, W J; Sung, S J

2011-09-15T23:59:59.000Z

402

Demonstration of Automated Heavy-Duty Vehicles  

E-Print Network (OSTI)

by compressed natural gas (CNG) in spark-ignition engines,buses are powered by a CNG spark-ignition engine, providedno matter whether it is a CNG or a diesel engine [4, 5].

2006-01-01T23:59:59.000Z

403

n-Butane: Ignition delay measurements at high pressure and detailed chemical kinetic simulations  

Science Conference Proceedings (OSTI)

Ignition delay time measurements were recorded at equivalence ratios of 0.3, 0.5, 1, and 2 for n-butane at pressures of approximately 1, 10, 20, 30 and 45 atm at temperatures from 690 to 1430 K in both a rapid compression machine and in a shock tube. A detailed chemical kinetic model consisting of 1328 reactions involving 230 species was constructed and used to validate the delay times. Moreover, this mechanism has been used to simulate previously published ignition delay times at atmospheric and higher pressure. Arrhenius-type ignition delay correlations were developed for temperatures greater than 1025 K which relate ignition delay time to temperature and concentration of the mixture. Furthermore, a detailed sensitivity analysis and a reaction pathway analysis were performed to give further insight to the chemistry at various conditions. When compared to existing data from the literature, the model performs quite well, and in several instances the conditions of earlier experiments were duplicated in the laboratory with overall good agreement. To the authors' knowledge, the present paper presents the most comprehensive set of ignition delay time experiments and kinetic model validation for n-butane oxidation in air. (author)

Healy, D.; Curran, H.J. [Combustion Chemistry Centre, School of Chemistry, NUI Galway (Ireland); Donato, N.S.; Aul, C.J.; Petersen, E.L. [Department of Mechanical Engineering, Texas A and M University, College Station, TX (United States); Zinner, C.M. [Mechanical, Materials and Aerospace Engineering, University of Central Florida, Orlando, FL (United States); Bourque, G. [Rolls-Royce Canada Limited, 9500 Cote de Liesse, Lachine, Quebec, H8T 1A2 (Canada)

2010-08-15T23:59:59.000Z

404

Calculation of the proportion of reactive waste for hydrogen ignition scenario  

DOE Green Energy (OSTI)

This study was conducted as outlined in NHC Letter of Instruction 9751330 dated February 247 1997 and entitled {open_quotes}Analysis by Pacific Northwest National Laboratory to Support a Safety Assessment for Rotary Mode Core Sampling in Flammable Gas Watchlist Tanks{close_quotes}. As prescribed in this letter, the results of this study were provided to Los Alamos National Laboratory (LANL) to revise the safety assessment document. Sampling Hanford tanks with a rotary drill could result in a drill-bit overheating accident which could ignite flammable gases present in the tanks. According to calculations, an over-heated drill bit could not get hot enough to ignite the hydrogen directly. However, an overheated drill bit could ignite saltcake waste containing high concentrations of organics, and a local organics burn would achieve sufficient temperature to ignite flammable gas present in the waste. This report estimates one quantity required to evaluate this particular accident scenario; the fraction of reactive waste in the tank waste. Reactive waste is waste that contains sufficient organic carbon and a low enough moisture content to ignite when in contact with an over-heated drill bit. This report presents a methodology to calculate the proportion of reactive waste for the 100 series tanks, using sampling data from tank characterization studies. The tanks are ranked according to their reactive waste proportions, and confidence limits are assigned to the estimates.

Gao, Feng; Heasler, P.G.

1997-04-01T23:59:59.000Z

405

Auto-ignition during instationary jet evolution of dimethyl ether (DME) in a high-pressure atmosphere  

Science Conference Proceedings (OSTI)

The auto-ignition process during transient injection of gaseous dimethyl ether (DME) in a constant high-pressure atmosphere is studied experimentally by laser-optical methods and compared with numerical calculations. With different non-intrusive measurement techniques jet properties and auto-ignition are investigated at high temporal and spatial resolution. The open jet penetrates a constant pressure oxidative atmosphere of up to 4 MPa. During the transient evolution, the fuel jet entrains air at up to 720 K. The subsequent auto-ignition of the ignitable part of the jet occurs simultaneously over a wide spatial extension. The ignition delay times are not affected by variation of the nozzle exit velocity. Thus, the low-temperature oxidation is slow compared with the shorter time scales of mixing, so that chemical kinetics is dominating the process. The typical two-stage ignition is resolved optically with high-speed shadowgraphy at a sampling rate of 10 kHz. The 2D fields of jet velocity and transient mixture fraction are measured phase-coupled with Particle Image Velocimetry (PIV) and Tracer Laser Induced Fluorescence (LIF) during the time-frame of ignition. The instationary Probability Density Functions (PDF) of mixture fraction are described very well by Beta functions within the complete area of the open jet. Additional 1D flamelet simulations of the auto-ignition process are computed with a detailed reaction mechanism for DME [S. Fischer, F. Dryer, H. Curran, Int. J. Chem. Kinet. 32 (12) (2000) 713-740; H. Curran, S. Fischer, F. Dryer, Int. J. Chem. Kinet. 32 (12) (2000) 741-759]. Calculated ignition delay times are in very good agreement with the measured mean ignition delay times of 3 ms. Supplemental flamelet simulations address the influence of DME and air temperature, pressure and strain. Underneath a critical strain rate the air temperature is identified to be the most sensitive factor on ignition delay time. (author)

Fast, G.; Kuhn, D.; Class, A.G. [Institut fuer Kern- und Energietechnik, Forschungszentrum Karlsruhe GmbH, Weberstrasse 5, D-76133 Karlsruhe (Germany); Maas, U. [Institut fuer Technische Thermodynamik, Universitat Karlsruhe (TH), Kaiserstrasse 12, D-76128 Karlsruhe (Germany)

2009-01-15T23:59:59.000Z

406

The National Ignition Facility Status and Plans for Laser Fusion and High-Energy-Density Experimental Studies  

E-Print Network (OSTI)

The National Ignition Facility (NIF) currently under construction at the University of California Lawrence Livermore National Laboratory (LLNL) is a 192-beam, 1.8-megajoule, 500-terawatt, 351-nm laser for inertial confinement fusion (ICF) and high-energy-density experimental studies. NIF is being built by the Department of Energy and the National Nuclear Security Agency (NNSA) to provide an experimental test bed for the U.S. Stockpile Stewardship Program to ensure the country's nuclear deterrent without underground nuclear testing. The experimental program will encompass a wide range of physical phenomena from fusion energy production to materials science. Of the roughly 700 shots available per year, about 10% will be dedicated to basic science research. Laser hardware is modularized into line replaceable units (LRUs) such as deformable mirrors, amplifiers, and multi-function sensor packages that are operated by a distributed computer control system of nearly 60,000 control points. The supervisory control roo...

Moses, E I

2001-01-01T23:59:59.000Z

407

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

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

DOE/EIS-0236, Oakland Operations Office, National Ignition Facility DOE/EIS-0236, Oakland Operations Office, National Ignition Facility Final Supplemental Environmental Impact Statement to the Stockpile Stewardship and Management Programmatic Environmental Impact Statement Volume II: Response to Public Comments (January 2 DOE/EIS-0236, Oakland Operations Office, National Ignition Facility Final Supplemental Environmental Impact Statement to the Stockpile Stewardship and Management Programmatic Environmental Impact Statement Volume II: Response to Public Comments (January 2 DOE issued the Draft SEIS for public review and comment by mailings to stakeholders and by announcements in the Federal Register (FR) on November 5, 1999, (64 FR 60430) (Attachment 4 of Volume I) and on November 12, 1999 (64 FR 61635) correcting a document title (Attachment 5 of Volume I). On

408

Driving high-gain shock-ignited inertial confinement fusion targets by green laser light  

Science Conference Proceedings (OSTI)

Standard direct-drive inertial confinement fusion requires UV light irradiation in order to achieve ignition at total laser energy of the order of 1 MJ. The shock-ignition approach opens up the possibility of igniting fusion targets using green light by reducing the implosion velocity and laser-driven ablation pressure. An analytical model is derived, allowing to rescale UV-driven targets to green light. Gain in the range 100-200 is obtained for total laser energy in the range 1.5-3 MJ. With respect to the original UV design, the rescaled targets are less sensitive to irradiation asymmetries and hydrodynamic instabilities, while operating in the same laser-plasma interaction regime.

Atzeni, Stefano; Marocchino, Alberto; Schiavi, Angelo [Dipartimento SBAI, Universita di Roma 'La Sapienza' and CNISM, Via A. Scarpa 14-16, I-00161 Roma (Italy)

2012-09-15T23:59:59.000Z

409

Apparatus and method for igniting an in situ oil shale retort  

DOE Patents (OSTI)

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.

Chambers, Carlon C. (Grand Junction, CO)

1981-01-01T23:59:59.000Z

410

Fuel mixture stratification as a method for improving homogeneous charge compression ignition engine operation  

DOE Patents (OSTI)

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.

Dec, John E. (Livermore, CA); Sjoberg, Carl-Magnus G. (Livermore, CA)

2006-10-31T23:59:59.000Z

411

Report from the Integrated Modeling Panel at the Workshop on the Science of Ignition on NIF  

Science Conference Proceedings (OSTI)

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.

Marinak, M; Lamb, D

2012-07-03T23:59:59.000Z

412

Status of the National Ignition Facility Project, IG-0598 | Department...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

conventional facility; laser system; target experimental system; integrated computers and controls; assembly, installation, and refurbishment equipment; and utilities. To...

413

Use of plasma fuel systems at thermal power plants in Russia, Kazakhstan, China, and Turkey  

SciTech Connect

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.

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

414

The Making of Beauty: Aesthetic Spaces in the Fiction of D. H. Lawrence, Muriel Spark, and Virginia Woolf  

E-Print Network (OSTI)

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 original beauty in texts. Their works make perceptible the singularity of the beloved, while revealing the writers’ predicament in translating the beloved’s ineffability in texts. Taking the untranslatability of the beloved into consideration, this dissertation traces the ways in which these writers’ texts capture the beloved’s original beauty at moments of revelation, related to epiphanies entering the terrain of literary modernism. My study thereby scrutinizes the dynamics of images of beauty and their impacts on art and politics in the context of modernism. In doing so, I argue that the texts I consider express the beloved’s singularity in challenge of the beautified images that many other artists invented for self-directed purposes in the early and mid-twentieth century. First, I explore Lawrence’s creation of aesthetic spaces in Lady Chatterley’s Lover (1928) in keeping with his desire for making palpable visual spectacles through the text. Analyzing how this ambition helped to create the novel’s aesthetic scenes, I would like to define Lawrence as an aesthete whose aspiration lay in expressing the beauty of things. Then, I discuss Spark’s affection for her characters and her desire to visualize the figure’s originality in The Prime of Miss Jean Brodie (1961) and The Girls of Slender Means (1963). Considering Spark in relation to both modernists and Fascists, I propose that her making of the image of her character breaks away from Fascism’s aestheticization of human figures. Finally, I investigate Woolf’s love for words by focusing on “The Duchess and the Jeweller” (1938), a short story written for expressing various modes of beauty in words. Drawing to the represented link between words and smell, considered the most “wasteful” sense, I examine how the sensory medium makes perceptible intrinsic qualities of words, and argues that her depiction of words, linked to smell, reveals the anti-utilitarian nature of words, unconstrained by a craftsman’s manipulation of words.

Lee, Joori

2013-08-01T23:59:59.000Z

415

Application of Pulse Spark Discharges for Scale Prevention and Continuous Filtration Methods in Coal-Fired Power Plant  

SciTech Connect

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.

Cho, Young; Fridman, Alexander

2012-06-30T23:59:59.000Z

416

Reactivity Controlled Compression Ignition (RCCI) Combustion on a Multi-Cylinder Light-Duty Diesel Engine  

Science Conference Proceedings (OSTI)

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.

Curran, Scott [ORNL; Hanson, Reed M [ORNL; Wagner, Robert M [ORNL

2012-01-01T23:59:59.000Z

417

Process and apparatus for igniting a burner in an inert atmosphere  

DOE Patents (OSTI)

According to this invention there is provided a process and apparatus for the ignition of a pilot burner in an inert atmosphere without substantially contaminating the inert atmosphere. The process includes the steps of providing a controlled amount of combustion air for a predetermined interval of time to the combustor then substantially simultaneously providing a controlled mixture of fuel and air to the pilot burner and to a flame generator. The controlled mixture of fuel and air to the flame generator is then periodically energized to produce a secondary flame. With the secondary flame the controlled mixture of fuel and air to the pilot burner and the combustion air is ignited to produce a pilot burner flame. The pilot burner flame is then used to ignited a mixture of main fuel and combustion air to produce a main burner flame. The main burner flame then is used to ignite a mixture of process derived fuel and combustion air to produce products of combustion for use as an inert gas in a heat treatment process.

Coolidge, Dennis W. (Katy, TX); Rinker, Franklin G. (Perrysburg, OH)

1994-01-01T23:59:59.000Z

418

The Development of Indirect Drive ICF and the Countdown to Ignition Experiments on the NIF  

E-Print Network (OSTI)

The Development of Indirect Drive ICF and the Countdown to Ignition Experiments on the NIF Maxwell Prize Address APS Division of Plasma Physics Meeting November 15, 2007 John Lindl NIF and Photon Science.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 #12;The NIF

419

NNSA Defense Programs Inertial Confinement Fusion Ignition and High Yield Campaign  

E-Print Network (OSTI)

and the NIF Project #12;2 Outline · National Nuclear Security Administration · ICF Campaign and Stewardship overview · NIF Use Plan ­ Defense Science Board review (Ignition 2010) · Recent progress ­ NIF, OMEGA, Z Confinement Fusion Acting Director Dr. Richard K. Thorpe NA-161 Office of the NIF Project Acting Director

420

The ignitability potential of uranium {open_quotes}roaster oxide{close_quotes}  

SciTech Connect

The oxidation of uranium to form Uranium `roaster oxide` was investigated with respect to concerns of unreacted metal remaining in the roaster oxide matrix. It was found that ignition of unreacted uranium chips in the roaster oxide as synthesized is unlikely under normal storage conditions.

Stakebake, J.L.

1994-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "ignition system spark" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

The Edward teller medal lecture: High intensity lasers and the road to ignition  

SciTech Connect

There has been much progress in the development of high intensity lasers and in the science of laser driven inertially confined fusion such that ignition is now a near term prospect. This lecture reviews the field with particular emphasis on areas of my own involvement. {copyright} {ital 1997 American Institute of Physics.}

Key, M.H. [Lawrence Livermore National Laboratory, Livermore, California94551 (United States)

1997-04-01T23:59:59.000Z

422

The Edward Teller medal lecture: High intensity lasers and the road to ignition  

SciTech Connect

There has been much progress in the development of high intensity lasers and in the science of laser driven inertially confined fusion such that ignition is now a near term prospect. This lecture reviews the field with particular emphasis on areas of my own involvement.

Key, M. H. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)

1997-04-15T23:59:59.000Z

423

Edward Teller medal lecture: high intensity lasers and the road to ignition  

SciTech Connect

There has been much progress in the development of high intensity lasers and in the science of laser driven inertially confined fusion such that ignition is now a near term prospect. This lecture reviews the field with particular emphasis on areas of my own involvement.

Key, M.H.

1997-06-02T23:59:59.000Z

424

Detailed Analysis and Control Issues of Homogeneous Charge Compression Ignition (HCCI)  

DOE Green Energy (OSTI)

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.

Aceves, Salvador M.; Flowers, Daniel L.; Martinez-Frias, Joel; Espinosa-Loza, Francisco; Dibble, Robert

2002-08-25T23:59:59.000Z

425

An experimental investigation of the ignition properties of hydrogen and carbon monoxide  

E-Print Network (OSTI)

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

Wooldridge, Margaret S.

426

Nuclear diagnostics for the National Ignition Facility ,,invited... Thomas J. Murphy,a)  

E-Print Network (OSTI)

Nuclear diagnostics for the National Ignition Facility ,,invited... Thomas J. Murphy,a) Cris W unprecedented opportunities for the use of nuclear diagnostics in inertial confinement fusion experiments to produce up to 1019 DT neutrons. In addition to a basic set of nuclear diagnostics based on previous

427

Ignition of a deuterium micro-detonation with a gigavolt super marx generator  

E-Print Network (OSTI)

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.

Friedwardt Winterberg

2008-12-01T23:59:59.000Z

428

Assessment of Potential for Ion Driven Fast Ignition  

E-Print Network (OSTI)

energy to multi-kilojoule laser systems indicates that conversionenergy short pulse lasers have conversion efficiencies below one percent, the conversion efficiency increases to a few percent for systems

2005-01-01T23:59:59.000Z

429

Assessment of Potential for Ion Driven Fast Ignition  

E-Print Network (OSTI)

energy to multi-kilojoule laser systems indicates that conversionenergy short pulse lasers have conversion efficiencies below one percent, the conversion efficiency increases to a few percent for systems

2004-01-01T23:59:59.000Z

430

Theoretical studies on hydrogen ignition and droplet combustion  

E-Print Network (OSTI)

chemical- kinetic pa- rameters that will have di?erent values for di?erent systems. Since applications

Del Álamo, Gonzalo

2006-01-01T23:59:59.000Z

431

Chemical Kinetic Reaction Mechanisms for Combustion of Hydrocarbon and Other Types of Chemical Fuels  

DOE Data Explorer (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.[Taken from https://www-pls.llnl.gov/?url=science_and_technology-chemistry-combustion

432

Kinetics of nickel precipitate formation in soils Edward Peltier and D. L. Sparks. Department of Plant and Soil Sciences, University of Delaware, 152  

E-Print Network (OSTI)

GEOC 26 Kinetics of nickel precipitate formation in soils Edward Peltier and D. L. Sparks. Department of Plant and Soil Sciences, University of Delaware, 152 Townsend Hall, Newark, DE 19711 and sequestration of nickel in contaminated soils. As these precipitates age, their stability increases, resulting

Sparks, Donald L.

433

Study of Technology for Detecting Pre-Ignition Conditions of ...  

Science Conference Proceedings (OSTI)

... analysis .of the 1988-1992 data collected through the National Fire Incident Reporting System, NFIRS ... K-type (C%romel-Alumel), grounded, 30 cm ...

1996-08-14T23:59:59.000Z

434

"Defense-in-Depth" Laser Safety and the National Ignition Facility  

SciTech Connect

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.

King, J J

2010-12-02T23:59:59.000Z

435

Advanced Liquid Natural Gas Onboard Storage System  

DOE Green Energy (OSTI)

Cummins Westport Incorporated (CWI) has designed and developed a liquefied natural gas (LNG) vehicle fuel system that includes a reciprocating pump with the cold end submerged in LNG contained in a vacuum-jacketed tank. This system was tested and analyzed under the U.S. Department of Energy (DOE) Advanced LNG Onboard Storage System (ALOSS) program. The pumped LNG fuel system developed by CWI and tested under the ALOSS program is a high-pressure system designed for application on Class 8 trucks powered by CWI's ISX G engine, which employs high-pressure direct injection (HPDI) technology. A general ALOSS program objective was to demonstrate the feasibility and advantages of a pumped LNG fuel system relative to on-vehicle fuel systems that require the LNG to be ''conditioned'' to saturation pressures that exceeds the engine fuel pressure requirements. These advantages include the capability to store more fuel mass in given-size vehicle and station tanks, and simpler lower-cost LNG refueling stations that do not require conditioning equipment. Pumped LNG vehicle fuel systems are an alternative to conditioned LNG systems for spark-ignition natural gas and port-injection dual-fuel engines (which typically require about 100 psi), and they are required for HPDI engines (which require over 3,000 psi). The ALOSS program demonstrated the feasibility of a pumped LNG vehicle fuel system and the advantages of this design relative to systems that require conditioning the LNG to a saturation pressure exceeding the engine fuel pressure requirement. LNG tanks mounted on test carts and the CWI engineering truck were repeatedly filled with LNG saturated at 20 to 30 psig. More fuel mass was stored in the vehicle tanks as well as the station tank, and no conditioning equipment was required at the fueling station. The ALOSS program also demonstrated the general viability and specific performance of the CWI pumped LNG fuel system design. The system tested as part of this program is designed to be used on Class 8 trucks with CWI ISX G HPDI engines. Extensive test cart and engineering truck tests of the pump demonstrated good durability and the high-pressure performance needed for HPDI application. The LNG tanks manufactured by Taylor-Wharton passed SAE J2343 Recommended Practice drop tests and accelerated road-load vibration tests. NER and hold-time tests produced highly consistent results. Additional tests confirmed the design adequacy of the liquid level sensor, vaporizer, ullage volume, and other fuel system components. While the testing work performed under this program focused on a high-pressure pumped LNG fuel system design, the results also validate the feasibility of a low-pressure pumped fuel system. A low-pressure pumped fuel system could incorporate various design refinements including a simpler and lighter-weight pump, which would decrease costs somewhat relative to a high-pressure system.

Greg Harper; Charles Powars

2003-10-31T23:59:59.000Z

436

Design of a viable homogeneous-charge compression-ignition (HCCI) engine : a computational study with detailed chemical kinetics  

E-Print Network (OSTI)

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 ...

Yelvington, Paul E., 1977-

2005-01-01T23:59:59.000Z

437

Investigations into the ignition behaviors of pulverized coals and coal blends in a drop tube furnace using flame monitoring techniques  

E-Print Network (OSTI)

fur- naces can simulate more closely the combustion conditions in industrial pulverized coal, Pan WP. Studying the mechanisms of ignition of coal particles by TG-DTA. Thermochim Acta 1996

Yan, Yong

438

On fuel selection in controlled auto-ignition engines : the link between intake conditions, chemical kinetics, and stratification  

E-Print Network (OSTI)

The objective of this research is to examine the impact fuel selection can have on the high-load limit in a stratified Compression Auto-Ignition (CAI) engine. This was accomplished by first studying the validity of the ...

Maria, Amir Gamal

2012-01-01T23:59:59.000Z

439

Shock timing on the National Ignition Facility: the first precision tuning series  

Science Conference Proceedings (OSTI)

Ignition implosions on the National Ignition Facility (NIF) [Lindl et al., Phys. Plasmas 11, 339 (2004)] are driven with a very carefully tailored sequence of four shock waves that must be timed to very high precision in order to keep the fuel on a low adiabat. The first series of precision tuning experiments on NIF have been performed. These experiments use optical diagnostics to directly measure the strength and timing of all four shocks inside the hohlraum-driven, cryogenic deuterium-filled capsule interior. The results of these experiments are presented demonstrating a significant decrease in the fuel adiabat over previously un-tuned implosions. The impact of the improved adiabat on fuel compression is confirmed in related deuterium-tritium (DT) layered capsule implosions by measurement of fuel areal density (rR), which show the highest fuel compression (rR {approx} 1.0 g/cm{sup 2}) measured to date.

Robey, H F; Celliers, P M; Kline, J L; Mackinnon, A J

2011-10-27T23:59:59.000Z

440

Prompt Beta Spectroscopy as a Diagnostic for Mix in Ignited NIF Capsules  

E-Print Network (OSTI)

The National Ignition Facility (NIF) technology is designed to drive deuterium-tritium (DT) internal confinement fusion (ICF) targets to ignition using indirect radiation from laser beam energy captured in a hohlraum. Hydrodynamical instabilities at interfaces in the ICF capsule leading to mix between the DT fue l and the ablator shell material are of fundamental physical interest and can affect the performance characteristics of the capsule. In this Letter we describe new radiochemical diagnostics for mix processes in ICF capsules with plastic or Be (0.9%Cu) ablator shells. Reactions of high-energy tritons with shell material produce high-energy $\\beta$-emitters. We show that mix between the DT fuel and the shell material enhances high-energy prompt beta emission from these reactions by more than an order of magnitude over that expected in the absence of mix.

A. C. Hayes; G. Jungman; J. C. Solem; P. A. Bradley; R. S. Rundberg

2004-08-12T23:59:59.000Z