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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
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1

Laser Spark Distribution and Ignition System  

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

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...

2

Laser Spark Distribution and Ignition System  

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

Laser spark distribution and ignition system  

DOE Patents [OSTI]

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

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

2008-09-02T23:59:59.000Z

4

Engines - Spark Ignition Engines  

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

5

Spark and Laser Ignition  

Science Journals Connector (OSTI)

In the context of nonshock initiation of secondary explosives, electric sparks and lasers represent sources of external power that may stimulate exothermic reaction in energetic materials, and generate enough ...

James E. Kennedy

2010-01-01T23:59:59.000Z

6

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

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

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

7

Ignition system  

SciTech Connect (OSTI)

This patent describes an ignition system of an internal combustion engine which consists of: a permanent magnet supported by a rotary member of the engine adapted to rotate in synchronism with a rotary shaft of the engine; a generating coil for generating an electromotive force to produce an electric current as the permanent magnet acts on the generating coil during the rotation of the rotary member; an ignition capacitor charged by the electric current generated by the generating coil; a thyristor caused to turn on by a counter electromotive force generated by the generating coil to thereby cause the ignition capacitor to begin to discharge; and an ignition coil generating a high voltage as the ignition capacitor begins to discharge, to cause a spark discharge to take place in an ignition plug of the internal combustion engine.

Kondo, T.; Ohno, S.

1986-09-16T23:59:59.000Z

8

Performance and exhaust emissions of a two-stroke spark-ignition engine with a direct-injection system  

Science Journals Connector (OSTI)

A direct fuel-injection system has been adapted to a small two-stroke spark-ignition engine to prevent the charge from flowing through the cylinder during the scavenging process. The injection system consists of a jerk-type pump and a single-hole nozzle which supplies gasoline to the cylinder. Engine tests were carried out for comparison with the carburettor version of the same engine. The results show that the direct-injection version can achieve greatly improved thermal efficiency and lower HC and CO emissions without intake throttling. In addition, NOx can be reduced to a much lower level than that of the ordinary four-stroke engine. Heat release analysis and high-speed photography indicate that stratified charge combustion takes place in the direct-injection engine.

Yasuhiro Daisho; Takeshi Saito; Noriaki Ishibe; Mitsuhiro Tsukada; Masashi Yukawa

1991-01-01T23:59:59.000Z

9

Near-frictionless carbon coatings for spark-ignited direct-injected fuel systems. Final report, January 2002.  

SciTech Connect (OSTI)

This report describes an investigation by the Tribology Section of Argonne National Laboratory (ANL) into the use of near-frictionless carbon (NFC) coatings for spark-ignited, direct-injected (SIDI) engine fuel systems. Direct injection is being pursued in order to improve fuel efficiency and enhance control over, and flexibility of, spark-ignited engines. SIDI technology is being investigated by the Partnership for a New Generation of Vehicles (PNGV) as one route towards meeting both efficiency goals and more stringent emissions standards. Friction and wear of fuel injector and pump parts were identified as issues impeding adoption of SIDI by the OTT workshop on ''Research Needs Related to CIDI and SIDI Fuel Systems'' and the resulting report, Research Needs Related to Fuel Injection Systems in CIDI and SIDI Engines. The following conclusions were reached: (1) Argonne's NFC coatings consistently reduced friction and wear in existing and reformulated gasolines. (2) Compared to three commercial DLC coatings, NFC provided the best friction reduction and protection from wear in gasoline and alternative fuels. (3) NFC was successfully deposited on production fuel injectors. (4) Customized wear tests were performed to simulate the operating environment of fuel injectors. (5) Industry standard lubricity test results were consistent with customized wear tests in showing the friction and wear reduction of NFC and the lubricity of fuels. (6) Failure of NFC coatings by tensile crack opening or spallation did not occur, and issues with adhesion to steel substrates were eliminated. (7) This work addressed several of the current research needs of the OAAT SIDI program, as defined by the OTT report Research Needs Related to Fuel Injection Systems in CIDI and SIDI Engines.

Hershberger, J.; Ozturk, O.; Ajayi, O. O.; Woodford, J. B.; Erdemir, A.; Fenske, G. R.

2002-04-05T23:59:59.000Z

10

Comparative experimental evaluation of performance, combustion and emissions of laser ignition with conventional spark plug in a compressed natural gas fuelled single cylinder engine  

Science Journals Connector (OSTI)

Abstract Laser is emerging as a strong concept for alternative ignition in spark ignition engine. Laser ignition has potential advantages over conventional spark plug ignition. Laser ignition system is free from spark electrodes hence there is no loss of spark energy to the electrodes, which are also free from erosion effect. In addition, there is flexibility in choosing spark location and it offers excellent performance under high in-cylinder pressures. In this paper, performances of laser ignition and conventional spark ignition systems are comparatively evaluated in terms of in-cylinder pressure variation, combustion stability, fuel consumption, power output and exhaust emissions at similar operating conditions of the engine.

Dhananjay Kumar Srivastava; Avinash Kumar Agarwal

2014-01-01T23:59:59.000Z

11

Laser-induced spark ignition fundamental and applications  

Science Journals Connector (OSTI)

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 50 MPa 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 X. Phuoc

2006-01-01T23:59:59.000Z

12

Simulation of Landfill Gas Performance in a Spark Ignited Engine.  

E-Print Network [OSTI]

?? Computer simulations were performed using KIVA-4 code to determine performance of a spark ignited engine fueled by methane diluted with carbon dioxide to approximate… (more)

Swain, Daniel P.

2010-01-01T23:59:59.000Z

13

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

SciTech Connect (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

14

Air Charge Control for Turbocharged Spark Ignition Engines with Internal Exhaust Gas Recirculation  

E-Print Network [OSTI]

, the turbocharger wastegate, and the Variable Valve Timing (VVT) system are three actuators in the air path systemAir Charge Control for Turbocharged Spark Ignition Engines with Internal Exhaust Gas Recirculation of transient cylin- der charge control, based on a cycle-averaged mean-value model for a turbocharged spark

Stefanopoulou, Anna

15

Engines - Spark Ignition Engines - Direct Injection - Omnivorous Engine  

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

16

Large Eddy Simulation of spark ignition in a turbulent methane jet  

E-Print Network [OSTI]

and propagation and (4) stabilization. In the context of laser and electrical spark ignition (which is the scope applications of laser ignition and comparison with standard spark plug devices. Phuoc et al. [5] presentLarge Eddy Simulation of spark ignition in a turbulent methane jet G. Lacaze a , E. Richardson b

Paris-Sud XI, Université de

17

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

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

18

Comparative studies of methane and propane as fuels for spark ignition and compression ignition engines  

SciTech Connect (OSTI)

The paper reviews the combustion characteristics of the two fuels and sets out to consider their respective performance in both spark ignition and compression ignition engines. Results of comparative tests involving spark ignition engines over a wide range of operating conditions are presented and discussed. Some of the performance characteristics considered are those relating to power output, efficiency, tendency to knock, cyclic variations, optimum spark requirements and exhaust emissions. Similarly, some of the performance characteristics in compression ignition engines considered include power output, efficiency, tendency towards knock and autoignition, exhaust emissions and low operational temperature problems. Finally, the relative operational safety aspects of the two fuels are evaluated. It is then suggested that in this regard, methane has some excellent physical, chemical and combustion characteristics that makes it a particularly safe fuel.

Karim, G.A.; Wierzba, I.

1983-08-01T23:59:59.000Z

19

Laser-induced spark ignition of H2/O2/Ar mixtures  

Science Journals Connector (OSTI)

Laser-induced spark ignition of hydrogen-oxygen-argon mixtures was experimentally investigated using a Q-swiched Nd:YAG laser to break down the gas at 532 nm. The laser-based high-speed schlieren system was emplo...

ChangJian Wang; ShengLi Xu; GuangMing Jia

2007-12-01T23:59:59.000Z

20

A comparative study of laser ignition and spark ignition with gasoline–air mixtures  

Science Journals Connector (OSTI)

Abstract The ignition probability and minimum ignition energy (MIE) of premixed gasoline–air mixture for different equivalence ratio was experimentally studied using a nanosecond pulse at 532 nm and 1064 nm from a Q-switched Nd:YAG laser in a constant-volume combustion chamber (CVCC) The result was compared with the spark ignition. The initial pressure and temperature of the mixture was 0.1 MP and 363 K, respectively. The research indicates that within the flammable range, the probability increases when the ignition energy increases and the distribution of MIE with the equivalence ratios is U-shape for both laser and spark ignition. For laser ignition with 532 nm, when the incident energy is higher than 110 mJ or the absorbed energy is high than 31 mJ, 100% of ignition could be obtained within equivalence ratios of 0.8–1.6. For 1064 nm it is 235 mJ and 30 mJ. To get the same ignition probability of mixture with identical equivalence ratio, the incident energy of 1064 nm is twice more than the incident energy of 532 nm, while the absorbed energy values are virtually the same. It indicates that significant wavelength dependence is expected for the initial free electrons but irrelevant for the process of absorbing energy. The initial free electrons are produced from impurities in gasoline–air mixture because the intensity in the focus (1012 W/cm2) is too low to ionize gas molecules via the multi-photon ionization process, which requires higher irradiance (?1014 W/cm2). The MIE obtained with a laser-spark ignition is greater than that measured by electrical sparks. The MIE for laser ignition was obtained at equivalence ratio of 1.0 both of 532 nm and 1064 nm, and it was 13.5 mJ and 9.5 mJ, respectively. But for spark ignition, the MIE is 3.76 mJ with equivalence ratio of 1.6. What?s more, laser ignition extends the lean flammability limit from 0.8 to 0.6.

Cangsu Xu; Donghua Fang; Qiyuan Luo; Jian Ma; Yang Xie

2014-01-01T23:59:59.000Z

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

Burner ignition system  

DOE Patents [OSTI]

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

22

Laser induced spark ignition of coaxial methane/oxygen/nitrogen diffusion flames  

Science Journals Connector (OSTI)

We report the laser induced spark ignition (LSI) of coaxial methane/oxygen/nitrogen diffusion flames using the 1064 nm output of a Q-switched Nd:YAG laser. The minimum ignition energy...

Li, Xiaohui; Yu, Yang; Yu, Xin; Liu, Chang; Fan, Rongwei; Chen, Deying

2014-01-01T23:59:59.000Z

23

Ignition of a combustible gas mixture by a laser spark excited in the reactor volume  

Science Journals Connector (OSTI)

Ignition of a stoichiometric CH4: O2 mixture by a laser spark excited in the reactor volume is ... which indicates fast (involving branching chain reactions) ignition of the gas mixture. A conclusion is ... regar...

S. Yu. Kazantsev; I. G. Kononov; I. A. Kossyi; N. M. Tarasova…

2009-03-01T23:59:59.000Z

24

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

Boyer, Edmond

25

Laser Spark Ignition of Premixed Methane-Air Mixtures: Parameter Measurements and Determination of Key Factors for Ultimate Ignition Results  

Science Journals Connector (OSTI)

In this study, we present an experimental investigation of the parameters of the laser spark ignition of premixed methane-air mixtures and the determination of the key factors for the...

Li, Xiaohui; Smith, Benjamin W; Omenetto, Nicoló

2014-01-01T23:59:59.000Z

26

Turbocharged spark ignition engine modelling and control strategy  

Science Journals Connector (OSTI)

This paper deals with the non-linear modelling and control of a turbocharged spark ignition engine. In the automotive industry, downsizing-based turbocharging is considered as a powerful technique to improve engine performances as fuel economy, pumping loss reduction to increase engine efficiency or driveability optimisation. This method is largely used for diesel engines. For gasoline engines, it is more complex in terms of control. In this work, a simplified control-oriented model is presented and validated using a Smart MCC three cylinders engine data. Then, based on this model, a fuzzy non-linear control law is calculated to achieve the fuel consumption and pumping losses reduction by setting the engine states to a given profile.

D. Khiar; J. Lauber; T.M. Guerra; T. Floquet; G. Colin; Y. Chamaillard

2008-01-01T23:59:59.000Z

27

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

E-Print Network [OSTI]

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

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

2004-01-01T23:59:59.000Z

28

A user-friendly computer simulation of a spark ignition engine  

E-Print Network [OSTI]

A USER-FRIENDLY COMPUTER SIMULATION OF A SPARK IGNITION ENGINE A Thesis by IVAN BERRIOS Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE... August 1993 Major Subject: Mechanical Engineering A USER-FRIENDLY COMPUTER SIMULATION OF A SPARK IGNITION ENGINE A Thesis by IVAN BERRIOS Submitted to Texas A&M University in partial fulfillment of the requirements for the degree of MASTER...

Berrios, Ivan

2012-06-07T23:59:59.000Z

29

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

SciTech Connect (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

30

Thermal ignition combustion system  

SciTech Connect (OSTI)

A thermal ignition combustion system adapted for use with an internal combustion engine is described comprising: (a) means for providing ignition chamber walls defining an ignition chamber, the chamber walls being made of a material having a thermal conductivity greater than 20 W/m/sup 0/C. and a specific heat greater than 480J/kg/sup 0/C., the ignition chamber being in constant communication with the main combustion chamber; (b) means for maintaining the temperature of the chamber walls above a threshold temperature capable of causing ignition of a fuel; and (c) means for conducting fuel to the ignition chamber.

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

1988-04-19T23:59:59.000Z

31

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

32

Thermal ignition combustion system  

SciTech Connect (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.degree. C. and a specific heat greater than 480 J/kg.degree. 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.

Kamo, Roy (Columbus, IN); Kakwani, Ramesh M. (Columbus, IN); Valdmanis, Edgars (Columbus, IN); Woods, Melvins E. (Columbus, IN)

1988-01-01T23:59:59.000Z

33

Laser ignition  

Science Journals Connector (OSTI)

Due to their thermodynamic benefits, second-generation spark-ignition engines with gasoline direct injection systems have ... combination of a spray-guided combustion process with laser-induced ignition allows th...

Bernhard Geringer; Dominikus Klawatsch; Josef Graf; Hans Peter Lenz…

2004-03-01T23:59:59.000Z

34

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

35

Motion planning for experimental air path control of a variable-valve-timing spark ignition engine  

E-Print Network [OSTI]

to driveability problems) and on the fuel/air ratio (FAR) (leading to pollution peaks). To compensateMotion planning for experimental air path control of a variable-valve-timing spark ignition engine Syste´mes, Mines-ParisTech 60, bd St Michel, 75272 Paris, France a r t i c l e i n f o Article history

36

Studies on the effect of turbulence on the performance characteristics of a spark-ignition engine  

Science Journals Connector (OSTI)

Turbulence in a spark-ignition engine significantly influences the performance and emission characteristics. Furthermore, it has been recognised that the presence of turbulence in the inlet manifold of a spark-ignition engine up to a certain level does improve the fuel economy. Hence, in this article, experimental investigations relating to the effect of turbulence generation in the inlet manifold on the overall performance of a spark-ignition engine are reported. Turbulence generators creating 50 and 75 per cent blockage with delta-wing-type blades were used in the inlet manifold of a single-cylinder spark-ignition engine. Subsequently, blade-type turbulence generation were introduced in the same manifold. A comparison between the two cases was made with reference to the overall performance of the engine by measuring the engine power and the turbulence with the help of a hot-wire anemometer. These investigations have shown that blade-type turbulence generators create a significantly larger amount of turbulence, leading to a loss of engine power compared with the delta-wing-shaped generator. However, it is noticed that there is a slight improvement in the performance of the engine when the delta-wing-type of turbulence generator is used compared with the conventional engine.

M.K. Gajendra Babu; R. Sabharwal; P. Sarcar; J.P. Subrahmanyam

1991-01-01T23:59:59.000Z

37

Explicit-Ready Nonlinear Model Predictive Control for Turbocharged Spark-Ignited Engines  

E-Print Network [OSTI]

Explicit-Ready Nonlinear Model Predictive Control for Turbocharged Spark- Ignited Engines J. El with saturated actuators. In this context, the need for model-based control laws is greater than ever with saturated actuators. In this paper, we evaluate the benefits of a nonlinear model predictive control (NMPC

Paris-Sud XI, Université de

38

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

39

Mathematical analysis of spark ignition engine operation via the combination of the first and second laws of thermodynamics  

Science Journals Connector (OSTI)

...cycle simulation of the diesel cycle: exergy as a second...Shapiro, H. N. 2000 Fundamentals of engineering thermodynamic...on a turbo-charged diesel engine performance and exergy...spark ignition engine cycle using first and second...

2008-01-01T23:59:59.000Z

40

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

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

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

E-Print Network [OSTI]

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

Dimou, Iason

42

Ignition study of acetone/air mixtures by using laser-induced spark  

Science Journals Connector (OSTI)

The breakdown and the laser-induced spark ignition of acetone–air mixtures were experimentally studied using a nanosecond pulse at 1064 nm from a Q-switched Nd:YAG laser. The breakdown was first characterized for different mixtures with acetone and air. This part of the work highlighted the wide variation in the energy absorbed by the plasma during a breakdown. We also demonstrated that the presence of acetone in air tends to reduce the energy required to obtain a breakdown. Next, the ignition of acetone–air mixtures in the equivalence ratio range 0.9–2.4 was investigated. The probabilities of ignition were calculated in function to the laser energy. However, according to the variability of energy absorption by the plasma, we preferred to present the result according to the energy absorbed by the plasma. The minimum ignition energies were also provided. The minimum ignition energy was obtained for an equivalence ratio of 1.6 and an absorbed energy of 1.15 mJ. Finally the characteristics of the plasma (absorption coefficient and kernel temperature) were calculated for the experiments corresponding to minimum ignition energies.

Virginie Tihay; Philippe Gillard; Denis Blanc

2012-01-01T23:59:59.000Z

43

Railplug Ignition System for Enhanced Engine Performance and Reduced Maintenance  

SciTech Connect (OSTI)

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

44

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

SciTech Connect (OSTI)

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

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

2009-08-15T23:59:59.000Z

45

Premix charge, compression ignition combustion system optimization...  

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

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

46

Energetic and exergetic analyses of a variable compression ratio spark ignition gas engine  

Science Journals Connector (OSTI)

Abstract Considering the significance of obtaining higher efficiencies from internal combustion engines (ICE) along with the growing role of natural gas as a fuel, the present work is set to explore the effects of compression ratio (CR hereafter) and air/fuel equivalence ratio (AFER hereafter) on the energy and exergy potentials in a gas-fueled spark ignition internal combustion engine. Experiments are carried out using a single cylinder, port injection, water cooled, variable compression ratio (VCR hereafter), spark ignition engine at a constant engine speed of 2000 rpm. The study involves \\{CRs\\} of 12, 14 and 16 and 10 \\{AFERs\\} between 0.8 and 1.25. Pure methane is utilized for the analysis. In addition, a natural gas blend with the minimum methane content among Iranian gas sources is also tested in order to investigate the effect of real natural gas on findings. The energy analysis involves input fuel power, indicated power and losses due to high temperature of exhaust gases and their unburned content, blow-by and heat loss. The exergy analysis is carried out for availability input and piston, exhaust, and losses availabilities along with destructed entropy. The analysis indicates an increase in the ratio of thermo-mechanical exhaust availability to fuel availability by CR with a maximum near stoichiometry, whereas it is shown that chemical exhaust exergy is not dependent on CR and reduces with AFER. In addition, it is indicated that the ratio of actual cycle to Otto cycle thermal efficiencies is about constant (about 0.784) with changing CR, AFER and CNG fuel used.

A. Javaheri; V. Esfahanian; A. Salavati-Zadeh; M. Darzi

2014-01-01T23:59:59.000Z

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

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

E-Print Network [OSTI]

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

Villarroel, Milivoy

2004-11-15T23:59:59.000Z

49

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

Science Journals Connector (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 model for fuel Injection Time (IT) in order to design a neuro-fuzzy controller for improving the performance of the spark ignition engine. The obtained results showed that the developed neuro-fuzzy model is capable of predicting the fuel IT with a mean squared error less than 0.0072. Furthermore, the power produced by the neuro-fuzzy controller has higher values of about 15-73% than the power produced by the PID controller used in the basic engine. The BSFC is reduced by about 2-5% compared to the PID controller.

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

2010-01-01T23:59:59.000Z

50

Combustion behavior of a spark ignition engine fueled with synthetic gases derived from biogas  

Science Journals Connector (OSTI)

Abstract Combustion results obtained from a spark ignition engine fueled with two synthetic gases obtained from catalytic decomposition of biogas are presented in this paper. These results are compared with those obtained when the engine was fueled with gasoline, methane and with the biogas from which synthetic gases are extracted. Experimental tests were performed under a wide range of speeds and at three equivalence ratios. Results showed that fractions of hydrogen in synthetic gases increased maximum pressures inside cylinder. Moreover, peak pressures were detected closer to top dead center than methane and biogas. Despite the fraction of diluents in the composition of synthetic gases, high speeds and lean conditions resulted in higher indicated efficiencies than those obtained with gasoline. Moreover, combustion speed and heat release rate were strongly influenced by the proportion of diluents and hydrogen in gaseous blends. CO and CO2 content in the composition of synthetic gases contributed to increase the exhaust concentrations of these pollutants compared with the other fuels, while HC decreased because of the small fraction of methane which remained unburned. Although \\{NOx\\} emissions were mitigated by diluents, like CO2 and air excess, high hydrogen fraction in composition of syngas involved elevated \\{NOx\\} emissions due to the increase in flame temperature that hydrogen produces.

J. Arroyo; F. Moreno; M. Muńoz; C. Monné; N. Bernal

2014-01-01T23:59:59.000Z

51

Inevitability of Engine-Out Nox Emissions from Spark-Ignition and Diesel Engines  

SciTech Connect (OSTI)

Internal combustion engines, both spark ignition and Diesel, are dominant types of vehicle power sources and also provide power for other important stationary applications. Overall, these engines are a central part of power generation in modern society. However, these engines, burning hydrocarbon fuels from natural gas to gasoline and Diesel fuel, are also responsible for a great deal of pollutant emissions to the environment, especially oxides of nitrogen (NO{sub x}) and unburned hydrocarbons (UHC). In recent years, pollutant species emissions from internal combustion engines have been the object of steadily more stringent limitations from various governmental agencies. Engine designers have responded by developing engines that reduce emissions to accommodate these tighter limitations. However, as these limits become ever more stringent, the ability of engine design modifications to meet those limits must be questioned. Production of NO{sub x} in internal combustion engines is primarily due to the high temperature extended Zeldovich reaction mechanism: (1) O + N{sub 2} = NO + N; (2) N + O{sub 2} = NO + O; and (3) N + OH = NO + H. The rates of these reactions become significant when combustion temperatures reach or exceed about 2000K. This large temperature dependence, characterized by large activation energies for the rates of the reactions listed here, is a direct result of the need to break apart the tightly bonded oxygen and nitrogen molecules. The strongest bond is the triple bond in the N {triple_bond} N molecule, resulting in an activation energy of about 75 kcal/mole for Reaction (1), which is the principal cause for the large temperature dependence of the extended Zeldovich NO{sub x} mechanism. In most engines, NO{sub x} is therefore produced primarily in the high temperature combustion product gases. Using a reliable kinetic model for NO{sub x} production such as the GRI Mechanism [1] or the Miller-Bowman model [2] with hydrocarbon products at temperatures from 1500K through 2500K, the amounts of NO{sub x} produced at a given residence time in an engine can easily be computed, as shown in Figure 1. Figure 1 depicts how temperatures such as those existing in the combustion zones of heavy-duty engines would produce NO{sub x} emissions. This figure was created assuming that a fuel/air equivalence ratio {phi} of 0.65 was used to heat the combustion air. This equivalence ratio would be similar to that of a heavy-duty lean-burn spark-ignition or diesel engine. At temperatures in the neighborhood of 2000K and residence times between 1-5 milliseconds, which are typical of residence times at these temperatures in engines, the production of NO{sub x} increases dramatically. It is evident from Fig. 1 that product temperatures must remain below approximately 2100K to achieve extremely low NO{sub x} production levels in engines. This conclusion led to a combined experimental and modeling study of product gas temperatures in engine combustion and their influence on emission levels.

Flynn, P F; Hunter, G L; Farrell, L A; Durrett, R P; Akinyemi, O C; Westbrook, C K; Pitz, W J

2000-01-11T23:59:59.000Z

52

Spark ignition engine control strategies for minimising cold start fuel consumption under cumulative tailpipe emissions constraints  

Science Journals Connector (OSTI)

Abstract This paper proposes a methodology for minimising the fuel consumption of a gasoline fuelled vehicle during cold starting. It first takes a validated dynamic model of an engine and its aftertreatment reported in a previous study (Andrianov, Brear, & Manzie, 2012) to identify optimised engine control strategies using iterative dynamic programming. This is demonstrated on a family of optimisation problems, in which fuel consumption is minimised subject to different tailpipe emissions constraints and exhaust system designs. Potential benefits of using multi-parameter optimisation, involving spark timing, air–fuel ratio and cam timing, are quantified. Single switching control policies are then proposed that perform close to the optimised strategies obtained from the dynamic programming but which require far less computational effort.

D.I. Andrianov; C. Manzie; M.J. Brear

2013-01-01T23:59:59.000Z

53

Application of semi-direct injection for spark-ignition engine  

Science Journals Connector (OSTI)

This paper proposes an application of a motorcycle engine lean-burn system for improving engine efficiency and reducing exhaust emissions. This Semi-Direct Injection (SDI) system consists of a high swirl charge, injection during intake-valve opening, and air-assisted fuel injection. The fuel enters the cylinder directly through the intake valve near the middle intake stroke for a richer mixture around the spark plug. A 125 cc, 4-valve, Port-Fuel-Injection (PFI) engine was retrofitted by designing a control plate to enhance the swirl. The swirl ratio was increased to 3.8 and the lean limit was extended to 1.7 of lambda (excess air ratio). The engine was tested at the low-load region, which includes most operation points of the ECE-40 driving cycle. A complete engine performance map was conducted for comparison between SDI and original PFI engines. The results show that Brake-Specific Fuel Consumption (BSFC) decreased by 11.3%. Brake-specific exhaust emissions of NOx and CO decreased by 32.0% and 92.9%, respectively. The HC emission increased by 47.7%.

Yuh-Yih Wu; Bo-Chiuan Chen; Anh-Trung Tran

2010-01-01T23:59:59.000Z

54

Characterization of cycle-to-cycle variations in a natural gas spark ignition engine  

Science Journals Connector (OSTI)

Abstract In this work a study of the influence of the fuel/air equivalence ratio and engine rotational speed on the cycle-to-cycle variations in combustion in a natural gas spark ignition engine is presented. The study considers both classic estimators of cyclic dispersion and a new one, based on the burned mass and burning rate. The engine experimental conditions were as follows: Intake pressure 0.5 bar, while fuel/air equivalence ratio was changed from 1.0 to 0.63, and engine rotational speed was varied from 1000 rpm to 2500 rpm. For each equivalence ratio and engine speed, a diagnosis model is used to process the experimentally obtained combustion pressure data in order to provide combustion relevant results such as the mass burning rate at a cycle level. A procedure based on the use of genetic algorithms is used to obtain a very accurate and objective (without human intervention) adjustment of the optimum parameters needed for combustion diagnosis: angular positioning and pressure offset of the pressure register, dynamic compression ratio, and heat transfer coefficients. The model allows making the diagnosis of series of 830 consecutive engine cycles in an automatic way, increasing the objectivity of the combustion diagnosis. The paper focuses on using the values of the mass fraction burned computed from the pressure register and especially on the analysis of the combustion cycle to cycle variation in the natural gas fuelled engine. A new indicator for the study of cycle-to-cycle variations is proposed, i.e. the standard deviation of the mass fraction burning rate. The values of this new indicator are compared with other classic indicators, showing the same general trends. However, a deeper insight is provided on the combustion cyclic variation when the values of the new indicator are plotted as a function of the mass fraction burned, since this allows analyzing the cyclic variation along the combustion development in each cycle from a mass fraction burned of zero to one, with a relevant value at mass fraction burned of 0.5. More important is that the consideration of the dependence of the combustion variables (density, flame front surface, combustion speed) on the mass fraction burned allows ensemble averaging of all registered cycles for each value of mass fraction burned. This permits using the ensemble averaged mass fraction burning rate as an estimator of combustion speed. The analysis of the general trends of cyclic dispersion when engine speed and equivalence ratio are modified (1000, 1750 and 2500 rpm; 0.7, 0.8, 0.9 and 1.0) indicate that cycle-to-cycle variations show, as expected, a strong dependence on the engine rotational speed, increasing the variation with engine rpm. However, when the standard deviation of mass fraction burning rate is plotted as a function of mass fraction burned, there is a linear dependence on engine rpm, but only a very weak dependence on equivalence ratio. This means that the proposed estimator of cyclic dispersion is sensitive to only flow turbulent intensity and not to equivalence ratio.

M. Reyes; F.V. Tinaut; B. Giménez; A. Pérez

2015-01-01T23:59:59.000Z

55

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

SciTech Connect (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

56

Efficiency and emissions of a spark ignition engine fueled with synthetic gases obtained from catalytic decomposition of biogas  

Science Journals Connector (OSTI)

This paper presents the results of the tests developed in a naturally aspirated spark ignition engine, intended for installation in vehicles, fueled with synthetic gases obtained from catalytic decomposition of biogas. The experimental tests were carried out at three equivalence ratios and different speeds and loads. Two synthetic blends were used and the results were compared with those of gasoline and methane. Efficiency and emissions were calculated for the different fuels under the same operation conditions and it was found that at lean equivalence ratios, brake thermal efficiency with synthetic gases approached to the traditional fuels and even improved it at ? = 0.7. BSCO2 emissions increased due to the CO2 content of the gaseous blends. While CO increased at stoichiometric conditions, it decreased at lean conditions because the H2 contained in synthetic gases improved combustion at these conditions. BSHC measured were very low with synthetic gases because of the low content of methane in blends. The change in the fraction of H2 and CO2 of the synthetic blends led to quite different results in BSNOx. Syngas 1 \\{BSNOx\\} emissions were the lowest of all fuels, while syngas 2 \\{BSNOx\\} were the highest because of its high H2 fraction.

J. Arroyo; F. Moreno; M. Muńoz; C. Monné

2013-01-01T23:59:59.000Z

57

Effects of Some Oxygenated Substitutes on Gasoline Properties, Spark Ignition Engine Performance, and Emissions  

Science Journals Connector (OSTI)

It is worthwhile to mention that eucalyptol which can be steam-extracted from eucalyptus leaves has been tested as a co-solvent that prevents alcohol?gasoline blended fuels from phase separation. ... In this table, the compound along with the concentration in the respective base fuel, BRON, and its accuracy as well as relative effectiveness on a molar (RE-M) and a weight (RE-W) basis in comparison with MTBE are shown. ... All the compounds studied exhibited enhanced ignition quality, expressed with their capability to suppress engine knock, performance that can be confirmed from the BRON values of Table 3. From the data in the table, and given the accuracy of the BRON values, which is ±10/x, where x is the w/v % concentration of the compound in the fuel, a decrease of BRON values with the increase of the RON of the base fuel is observed. ...

S. Gouli; E. Lois; S. Stournas

1998-08-12T23:59:59.000Z

58

Use of hollow core fibers, fiber lasers, and photonic crystal fibers for spark delivery and laser ignition in gases  

Science Journals Connector (OSTI)

The fiber-optic delivery of sparks in gases is challenging as the output beam must be refocused to high

Joshi, Sachin; Yalin, Azer P; Galvanauskas, Almantas

2007-01-01T23:59:59.000Z

59

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

SciTech Connect (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

60

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"

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61

Investigation on characteristics of ionization current in a spark-ignition engine fueled with natural gas–hydrogen blends with BSS de-noising method  

Science Journals Connector (OSTI)

Investigation on ionization current characteristic in a spark-ignition engine fueled with natural gas, natural gas–hydrogen bends and gasoline was conducted. Blind Source Separation (BSS) de-noising method is employed to separate the ionization current signal from the interference of spark tail generated by ignition discharge. Cylinder pressure was recorded, and local temperature at spark plug gap is calculated using AVL-FIRE simulation code. Results show that the simulated cylinder pressures are in good agreement with those of measured and the spark tail and ionization current can be separated using BSS method. Front flame stage and post flame stage in ionization current can be used to analyze the combustion characteristics of natural gas–hydrogen blends. De-noised current shows that the appearance of front flame stage and post flame stage (including the peaks in the stages) fueled with natural gas is postponed and compared with that fueled with gasoline, and the appearance of front flame stage and post flame stage advance with the increase of hydrogen fraction in natural gas–hydrogen blends. In addition, the amplitude of ionization currents in both front flame and post flame (including the two peaks) fueled with natural gas gives lower values compared with those fueled with gasoline and hydrogen addition can increase the amplitude. Maximum post flame current shows similar trend to maximum cylinder pressure and it has good correlation between the timing of maximum post flame current and the timing of maximum cylinder pressure. High correlation coefficient between maximum post flame current and maximum pressure is presented.

Zhongquan Gao; Xiaomin Wu; Hui Gao; Bing Liu; Jie Wang; Xiangwen Meng; Zuohua Huang

2010-01-01T23:59:59.000Z

62

Laser ignition of a heterogeneous nickel-aluminum system  

Science Journals Connector (OSTI)

The ignition of a heterogeneous nickel—aluminum system by laser radiation is investigated experimentally. The ignition characteristics are investigated as a function of ... the samples. It is established that the...

Yu. S. Naiborodenko; V. M. Filatov

63

Chemical Kinetics of Hydrocarbon Ignition in Practical Combustion Systems  

SciTech Connect (OSTI)

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

Westbrook, C.K.

2000-07-07T23:59:59.000Z

64

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

65

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

SciTech Connect (OSTI)

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

Ted Bestor

2003-03-04T23:59:59.000Z

66

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

SciTech Connect (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

67

Experimental study on combustion characteristics of a spark-ignition engine fueled with natural gas–hydrogen blends combining with EGR  

Science Journals Connector (OSTI)

An experimental study on the effect of hydrogen fraction and EGR rate on the combustion characteristics of a spark-ignition engine fueled with natural gas–hydrogen blends was investigated. The results show that flame development duration, rapid combustion duration and total combustion duration are increased with the increase of EGR rate and decreased with the increase of hydrogen fraction in the blends. Hydrogen addition shows larger influence on flame development duration than that on rapid combustion duration. The coefficient of variation of the indicated mean effective pressure increases with the increase of EGR rate. And hydrogen addition into natural gas decreases the coefficient of variation of the indicated mean effective pressure, and this effectiveness becomes more obviously at high EGR rate. Engine fueled with natural gas–hydrogen blends combining with proper EGR rate can realize the stable low temperature combustion in gas engine.

Erjiang Hu; Zuohua Huang; Bing Liu; Jianjun Zheng; Xiaolei Gu

2009-01-01T23:59:59.000Z

68

Ignitor with stable low-energy thermite igniting system  

DOE Patents [OSTI]

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

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

1991-02-05T23:59:59.000Z

69

Syngas (H2/CO) in a spark-ignition direct-injection engine. Part 1: Combustion, performance and emissions comparison with CNG  

Science Journals Connector (OSTI)

Abstract The combustion, performance, and emissions of syngas (H2/CO) in a four-stroke, direct-injection, spark-ignition engine were experimentally investigated. The engine was operated at various speeds, ranging from 1500 to 2400 rev/min, with the throttle being held in the wide-open position. The start of fuel injection was fixed at 180° before the top dead center, and the ignition advance was set at the maximal brake torque. The air/fuel ratio was varied from the technically possible lowest excess air ratio (?) to lean operation limits. The results indicated that a wider air/fuel operating ratio is possible with syngas with a very low coefficient of variation. The syngas produced a higher in-cylinder peak pressure and heat-release rate peak and faster combustion than for CNG. However, CNG produced a higher brake thermal efficiency (BTE) and lower brake specific fuel consumption (BSFC). The BTE and BSFC of the syngas were on par to those of CNG at higher speeds. For the syngas, the total hydrocarbon emission was negligible at all load conditions, and the carbon monoxide emission was negligible at higher loads and increased under lower load conditions. However, the emission of nitrogen oxides was higher at higher loads with syngas.

Ftwi Yohaness Hagos; A. Rashid A. Aziz; Shaharin A. Sulaiman

2014-01-01T23:59:59.000Z

70

Effect of flow velocity and temperature on ignition characteristics in laser ignition of natural gas and air mixtures  

Science Journals Connector (OSTI)

Abstract Laser induced spark ignition offers the potential for greater reliability and consistency in ignition of lean air/fuel mixtures. This increased reliability is essential for the application of gas turbines as primary or secondary reserve energy sources in smart grid systems, enabling the integration of renewable energy sources whose output is prone to fluctuation over time. This work details a study into the effect of flow velocity and temperature on minimum ignition energies in laser-induced spark ignition in an atmospheric combustion test rig, representative of a sub 15 MW industrial gas turbine (Siemens Industrial Turbomachinery Ltd., Lincoln, UK). Determination of minimum ignition energies required for a range of temperatures and flow velocities is essential for establishing an operating window in which laser-induced spark ignition can operate under realistic, engine-like start conditions. Ignition of a natural gas and air mixture at atmospheric pressure was conducted using a laser ignition system utilizing a Q-switched Nd:YAG laser source operating at 532 nm wavelength and 4 ns pulse length. Analysis of the influence of flow velocity and temperature on ignition characteristics is presented in terms of required photon flux density, a useful parameter to consider during the development laser ignition systems.

J. Griffiths; M.J.W. Riley; A. Borman; C. Dowding; A. Kirk; R. Bickerton

2015-01-01T23:59:59.000Z

71

Laser Ignition in Internal Combustion Engines- a Novel Approach Based on Advanced Lasers  

Science Journals Connector (OSTI)

Laser ignition with its many potential advantages in comparison to conventional spark plug ignition has been investigated in detail. As ignition source several, to a certain extent...

Weinrotter, Martin; Kopecek, Herbert; Graf, Josef; Klausner, Johann; Herdin, Günther; Wintner, Ernst

72

Transonic Combustion ?- Injection Strategy Development for Supercritical Gasoline Injection-Ignition in a Light Duty Engine  

Broader source: Energy.gov [DOE]

Novel fuel injection equipment enables knock-free ignition with low noise and smoke in compression-ignition engines and low-particulates in spark-ignition engines.

73

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

SciTech Connect (OSTI)

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

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

2011-03-18T23:59:59.000Z

74

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

SciTech Connect (OSTI)

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

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

2013-01-01T23:59:59.000Z

75

Review and recent developments of laser ignition for internal combustion engines applications  

Science Journals Connector (OSTI)

Performance of future ignition system for internal combustion engines should be reliable and efficient to enhance and sustain combustion stability, since ignition not only initiates combustion but also influences subsequent combustion. Lean burn systems have been regarded as an advanced combustion approach that could improve thermal efficiency while reducing exhaust gas emissions. However, current engines cannot be operated sufficiently lean due to ignition related problems such as the sluggish flame initiation and propagation along with potential misfiring. A high exhaust gas recirculation engines also has similar potential for emissions improvement, but could also experience similar ignition problems, particularly at idle operation. Similarly, ignition is an important design factor in gas turbine and rocket combustor. Recently, non-conventional ignition techniques such as laser-induced ignition methods have become an attractive field of research in order to replace the conventional spark ignition systems. The fundamentals of conventional laser-induced spark ignition have been previously reviewed. Therefore, the objective of this article is to review progress on the use of such innovative techniques of laser-induced ignition including laser-induced cavity ignition and laser-induced multi-point ignition. In addition, emphasis is given to recent work to explore the feasibility of this interesting technology for practical applications concerning internal combustion engines.

Mohamed H. Morsy

2012-01-01T23:59:59.000Z

76

Part-load performance and emissions of a spark ignition engine fueled with RON95 and RON97 gasoline: Technical viewpoint on Malaysia’s fuel price debate  

Science Journals Connector (OSTI)

Abstract Due to world crude oil price hike in the recent years, many countries have experienced increase in gasoline price. In Malaysia, where gasoline are sold in two grades; RON95 and RON97, and fuel price are regulated by the government, gasoline price have been gradually increased since 2009. Price rise for RON97 is more significant. By 2014, its per liter price is 38% more than that of RON95. This has resulted in escalated dissatisfaction among the mass. People argued they were denied from using a better fuel (RON97). In order to evaluate the claim, there is a need to investigate engine response to these two gasoline grades. The effect of gasoline RON95 and RON97 on performance and exhaust emissions in spark ignition engine was investigated on a representative engine: 1.6L, 4-cylinder Mitsubishi 4G92 engine with CR 11:1. The engine was run at constant speed between 1500 and 3500 rpm with 500 rpm increment at various part-load conditions. The original engine ECU, a hydraulic dynamometer and control, a combustion analyzer and an exhaust gas analyzer were used to determine engine performance, cylinder pressure and emissions. Results showed that RON95 produced higher engine performance for all part-load conditions within the speed range. RON95 produced on average 4.4% higher brake torque, brake power, brake mean effective pressure as compared to RON97. The difference in engine performance was more significant at higher engine speed and loads. Cylinder pressure and ROHR were evaluated and correlated with engine output. With RON95, the engine produces 2.3% higher fuel conversion efficiency on average but RON97 was advantageous with 2.3% lower brake specific fuel consumption throughout all load condition. In terms of exhaust emissions, RON95 produced 7.7% lower \\{NOx\\} emission but higher CO2, CO and HC emissions by 7.9%, 36.9% and 20.3% respectively. Higher octane rating of gasoline may not necessarily beneficial on engine power, fuel economy and emissions of polluting gases. Even though there is some advantage using RON97 in terms of emission reduction of CO2, CO and HC, the 38% higher price and higher \\{NOx\\} emission is more expensive in the long run. Therefore using RON95 is economically better and environmentally friendlier. The findings provide some techno-economic evaluation on the fuel price debate that surround the Malaysia’s population in the recent years. The increased of fuel price may have limited their ability to use higher octane gasoline but it did not negatively affecting the users as they perceive.

Taib Iskandar Mohamad; Heoy Geok How

2014-01-01T23:59:59.000Z

77

Emissions and fuel economy of a vehicle with a spark-ignition, direct-injection engine : Mitsubishi Legnum GDI{trademark}.  

SciTech Connect (OSTI)

A 1997 Mitsubishi Legnum station wagon with a 150-hp, 1.8-L, spark-ignition, direct-injection (SIDI) engine was tested for emissions by using the FTP-75, HWFET, SC03, and US06 test cycles and four different fuels. The purpose of the tests was to obtain fuel-economy and emissions data on SIDI vehicles and to compare the measurements obtained with those of a port-fuel-injection (PFI) vehicle. The PFI vehicle chosen for the comparison was a 1995 Dodge Neon, which meets the Partnership for a New Generation of Vehicles (PNGV) emissions goals of nonmethane hydrocarbons (NMHC) less than 0.125 g/mi, carbon monoxide (CO) less than 1.7 g/mi, nitrogen oxides (NO{sub x} ) less than 0.2 g/mi, and particulate matter (PM) less than 0.01 g/mi. The Mitsubishi was manufactured for sale in Japan and was not certified to meet current US emissions regulations. Results show that the SIDI vehicle can provide up to 24% better fuel economy than the PFI vehicle does, with correspondingly lower greenhouse gas emissions. The SIDI vehicle as designed does not meet the PNGV goals for NMHC or NO{sub x} emissions, but it does meet the goal for CO emissions. Meeting the goal for PM emissions appears to be contingent upon using low-sulfur fuel and an oxidation catalyst. One reason for the difficulty in meeting the NMHC and NO{sub x} goals is the slow (200 s) warm-up of the catalyst. Catalyst warm-up time is primarily a matter of design. The SIDI engine produces more NMHC and NO{sub x} than the PFI engine does, which puts a greater burden on the catalyst to meet the emissions goals than is the case with the PFI engine. Oxidation of NMHC is aided by unconsumed oxygen in the exhaust when the SIDI engine operates in stratified-charge mode, but the same unconsumed oxygen inhibits chemical reduction of NO{sub x} . Thus, meeting the NO{sub x} emissions goal is likely to be the greatest challenge for the SIDI engine.

Cole, R. L.; Poola, R. B.; Sekar, R.

1999-04-08T23:59:59.000Z

78

Experimental Investigation of Spark-Ignited Combustion with High-Octane Biofuels and EGR. 2. Fuel and EGR Effects on Knock-Limited Load and Speed  

SciTech Connect (OSTI)

The present study experimentally investigates spark-ignited combustion with 87 AKI E0 gasoline in its neat form and in midlevel alcohol gasoline blends with 24% vol/vol isobutanol gasoline (IB24) and 30% vol/vol ethanol gasoline (E30). A single-cylinder research engine is used with an 11.85:1 compression ratio, hydraulically actuated valves, laboratory intake air, and was capable of external exhaust gas recirculation (EGR). Experiments were conducted with all fuels to full-load conditions with = 1, using both 0% and 15% external-cooled EGR. Higher octane number biofuel blends exhibited increased stoichiometric torque capability at this compression ratio, where the unique properties of ethanol enabled a doubling of the stoichiometric torque capability with E30 as compared to that of 87AKI, up to 20 bar IMEPg (indicating mean effective pressure gross) at = 1. The results demonstrate that for all fuels, EGR is a key enabler for increasing engine efficiency but is less useful for knock mitigation with E30 than for 87AKI gasoline or IB24. Under knocking conditions, 15% EGR is found to offer 1 CA of CA50 timing advance with E30, whereas up to 5 CA of CA50 advance is possible with knock-limited 87AKI gasoline. Compared to 87AKI, both E30 and IB24 are found to have reduced adiabatic flame temperature and shorter combustion durations, which reduce knocking propensity beyond that indicated by the octane number. However, E30+0% EGR is found to exhibit the better antiknock properties than either 87AKI+15% EGR or IB24+15% EGR, expanding the knock limited operating range and engine stoichiometric torque capability at high compression ratio. Furthermore, the fuel sensitivity (S) of E30 was attributed to reduced speed sensitivity of E30, expanding the low-speed stoichiometric torque capability at high compression ratio. The results illustrate that intermediate alcohol gasoline blends exhibit exceptional antiknock properties and performance beyond that indicated by the octane number tests, particularly E30.

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

2013-01-01T23:59:59.000Z

79

Laser Ignition of Alternative Liquid Fuels  

Science Journals Connector (OSTI)

Within a research project at the TU Vienna, the potential and mechanism of laser-induced ignition with respect to mixture inflammation and combustion were investigated compared to conventional spark ignition. A s...

Dr. Josef Graf; Dr. Thomas Lauer; Univ.-Prof. Dr. Bernhard Geringer

2012-05-01T23:59:59.000Z

80

State of Development of Laser Ignition  

Science Journals Connector (OSTI)

A holistic optimization of combustion engines with the aim of conserving resources has to include an improvement of the ignition mechanism as well. In the field of spark-ignition combustion engines the developmen...

Prof. Dr.-Ing. Dieter Brüggeman; Dipl.-Ing. Christian Hüttl

2009-03-01T23:59:59.000Z

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.


81

A Numerical Study of Transient Ignition in a Counter ow Nonpremixed Methane-Air Flame using  

E-Print Network [OSTI]

of hydrocarbon fuels, for example in diesel engines or in knocking of spark-ignition engines. Such processes

Petzold, Linda R.

82

Laser Ignition  

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

83

National Ignition Facility Cryogenic Target Systems Interim Management Plan  

SciTech Connect (OSTI)

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

Warner, B

2002-04-25T23:59:59.000Z

84

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

85

Effect of ignition location on the in-process removal of combustion deposits from the output window of a gas turbine laser ignition system  

Science Journals Connector (OSTI)

The effect of ignition location on the effectiveness of combustion deposit removal from the reverse side of an optical window in a laser ignition system for use in gas turbines is presented. Such deposits consist of carbon and other by-products which accumulate on the walls of the chamber as a result of incomplete combustion. In laser based ignition systems this accumulation of combustion deposits has the potential to reduce the transmissive properties of the output window required for transmission of the laser radiation into the combustion chamber, adversely affecting the likelihood of successful ignition. In this work, a full empirical study into the in-process removal of combustion deposits from the reverse side of the optical window in a laser ignition system using a Q-switched Nd:YAG laser is presented, with an emphasis on the effect of ignition location on the effectiveness of combustion deposit removal. In addition, the mechanism of deposit removal is discussed.

J. Griffiths; J. Lawrence; P. Fitzsimons

2013-01-01T23:59:59.000Z

86

Target diagnostic system for the national ignition facility (invited)  

SciTech Connect (OSTI)

A review of recent progress on the design of a diagnostic system proposed for ignition target experiments on the National Ignition Facility (NIF) will be presented. This diagnostic package contains an extensive suite of optical, x ray, gamma ray, and neutron diagnostics that enable measurements of the performance of both direct and indirect driven NIF targets. The philosophy used in designing all of the diagnostics in the set has emphasized redundant and independent measurement of fundamental physical quantities relevant to the operation of the NIF target. A unique feature of these diagnostics is that they are being designed to be capable of operating in the high radiation, electromagnetic pulse, and debris backgrounds expected on the NIF facility. The diagnostic system proposed can be categorized into three broad areas: laser characterization, hohlraum characterization, and capsule performance diagnostics. The operating principles of a representative instrument from each class of diagnostic employed in this package will be summarized and illustrated with data obtained in recent prototype diagnostic tests. {copyright} {ital 1997 American Institute of Physics.}

Leeper, R.J.; Chandler, G.A.; Cooper, G.W.; Derzon, M.S.; Fehl, D.L.; Hebron, D.E.; Moats, A.R.; Noack, D.D.; Porter, J.L.; Ruggles, L.E.; Ruiz, C.L.; Torres, J.A. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)] [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Cable, M.D.; Bell, P.M.; Clower, C.A.; Hammel, B.A.; Kalantar, D.H.; Karpenko, V.P.; Kauffman, R.L.; Kilkenny, J.D.; Lee, F.D.; Lerche, R.A.; MacGowan, B.J.; Moran, M.J.; Nelson, M.B.; Olson, W.; Orzechowski, T.J.; Phillips, T.W.; Ress, D.; Tietbohl, G.L.; Trebes, J.E. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)] [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Bartlett, R.J.; Berggren, R.; Caldwell, S.E.; Chrien, R.E.; Failor, B.H.; Fernandez, J.C.; Hauer, A.; Idzorek, G.; Hockaday, R.G.; Murphy, T.J.; Oertel, J.; Watt, R.; Wilke, M. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Bradley, D.K.; Knauer, J. [University of Rochester, Rochester, New York 14627 (United States)] [University of Rochester, Rochester, New York 14627 (United States); Petrasso, R.D.; Li, C.K. [Massachusetts Institute of Technology, Plasma Fusion Center, Cambridge, Massachusetts 02139 (United States)] [Massachusetts Institute of Technology, Plasma Fusion Center, Cambridge, Massachusetts 02139 (United States)

1997-01-01T23:59:59.000Z

87

A sonic spark chamber system with on-line computation for studying the reaction $\\pi^{-} + p -> f^{0} + n$ at 3 GeV/c  

E-Print Network [OSTI]

A sonic spark chamber system with on-line computation for studying the reaction $\\pi^{-} + p -> f^{0} + n$ at 3 GeV/c

Bird, L; West, D; Whitehead, G; Wood, E; Crabb, D G; Hutchinson, G W; McEwen, J G; Ott, R; Aitken, D; Hague, J; Jennings, R; Parsons, A J; Auld, E G

1964-01-01T23:59:59.000Z

88

HYDROGEN IGNITION MECHANISM FOR EXPLOSIONS IN NUCLEAR FACILITY PIPE SYSTEMS  

SciTech Connect (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

89

Investigation on Firing Behavior of the Spark-Ignition Engine Fueled with Methanol, Liquefied Petroleum Gas (LPG), and Methanol/LPG During Cold Start  

Science Journals Connector (OSTI)

It can be produced from synthesis gas (a mixture of carbon monoxide (CO) and hydrogen) that is formed by steam reforming of natural gas, by gasification of coal, or from biomass, all of which are available in abundance or renewable. ... Liguang et al.,(16) based on cycle-by-cycle control strategy on an EFI (electronic fuel injection) LPG engine, studied how to control the ignition cycle and performed both single-cycle and multicycle tests. ...

Changming Gong; Baoqing Deng; Shu Wang; Yan Su; Qing Gao; Xunjun Liu

2008-10-04T23:59:59.000Z

90

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

91

Programmable Beam Spatial Shaping System for the National Ignition Facility  

SciTech Connect (OSTI)

A system of customized spatial light modulators has been installed onto the front end of the laser system at the National Ignition Facility (NIF). The devices are capable of shaping the beam profile at a low-fluence relay plane upstream of the amplifier chain. Their primary function is to introduce 'blocker' obscurations at programmed locations within the beam profile. These obscurations are positioned to shadow small, isolated flaws on downstream optical components that might otherwise limit the system operating energy. The modulators were designed to enable a drop-in retrofit of each of the 48 existing Pre Amplifier Modules (PAMs) without compromising their original performance specifications. This was accomplished by use of transmissive Optically Addressable Light Valves (OALV) based on a Bismuth Silicon Oxide photoconductive layer in series with a twisted nematic liquid crystal (LC) layer. These Programmable Spatial Shaper packages in combination with a flaw inspection system and optic registration strategy have provided a robust approach for extending the operational lifetime of high fluence laser optics on NIF.

Heebner, J; Borden, M; Miller, P; Hunter, S; Christensen, K; Scanlan, M; Haynam, C; Wegner, P; Hermann, M; Brunton, G; Tse, E; Awwal, A; Wong, N; Seppala, L; Franks, M; Marley, E; Wong, N; Seppala, L; Franks, M; Marley, E; Williams, K; Budge, T; Henesian, M; Stolz, C; Suratwala, T; Monticelli, M; Walmer, D; Dixit, S; Widmayer, C; Wolfe, J; Bude, J; McCarty, K; DiNicola, J M

2011-01-21T23:59:59.000Z

92

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

SciTech Connect (OSTI)

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

Yalin, Azer [Seaforth, LLC

2014-03-30T23:59:59.000Z

93

Combustion system development of a two-stroke, spark-assisted DI diesel engine  

SciTech Connect (OSTI)

A loop-scavenged, two-stroke, spark-assisted DI diesel engine was developed by modifying an outboard marine gasoline engine to operate on diesel fuel with high fuel efficiency similar to a diesel engine, yet retain the two-stroke engine advantages of low cost, light weight, and high power-to-weight ratio. Engine modification was concentrated in the area of the combustion system, including transfer port design to generate air swirl in the cylinder, and combustion chamber design to generate air squish and turbulence. Bore and stroke (84 x 72 mm) remained the same as those of the base engine. The experimental engine used the production engine's piston, crankshaft, connecting rod, bearings, and cylinder block. The transfer port design was optimized using a flow test bench for best swirl and air flow pattern with a simple flow visualization technique. The best combustion chamber geometry, compression ratio, and fuel injection spray pattern were determined through engine experiments.

Ariga, S.; Matsushita, Y.

1988-01-01T23:59:59.000Z

94

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

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

95

Target diagnostic system for the national ignition facility (invited) R. J. Leeper, G. A. Chandler, G. W. Cooper, M. S. Derzon, D. L. Fehl, D. E. Hebron,  

E-Print Network [OSTI]

is a glass laser which will initially be used to demonstrate ignition and gain in an inertially confinedTarget diagnostic system for the national ignition facility (invited) R. J. Leeper, G. A. Chandler of a diagnostic system proposed for ignition target experiments on the National Ignition Facility NIF

96

Laser Ignition and Laser Induced Breakdown Spectroscopy in Engines Using Hollow Core Fiber Delivery  

Science Journals Connector (OSTI)

We describe the use of hollow core optical fibers to deliver laser sparks. The sparks are used to ignite engines and to enable air-to-fuel measurements by laser induced breakdown...

Joshi, Sachin; Yalin, Azer P; Dumitrescu, Cosmin; Olcmen, Semih; Puzinauskas, Paul

97

Large eddy simulation of forced ignition of an annular bluff-body burner  

SciTech Connect (OSTI)

The optimization of the ignition process is a crucial issue in the design of many combustion systems. Large eddy simulation (LES) of a conical shaped bluff-body turbulent nonpremixed burner has been performed to study the impact of spark location on ignition success. This burner was experimentally investigated by Ahmed et al. [Combust. Flame 151 (2007) 366-385]. The present work focuses on the case without swirl, for which detailed measurements are available. First, cold-flow measurements of velocities and mixture fractions are compared with their LES counterparts, to assess the prediction capabilities of simulations in terms of flow and turbulent mixing. Time histories of velocities and mixture fractions are recorded at selected spots, to probe the resolved probability density function (pdf) of flow variables, in an attempt to reproduce, from the knowledge of LES-resolved instantaneous flow conditions, the experimentally observed reasons for success or failure of spark ignition. A flammability map is also constructed from the resolved mixture fraction pdf and compared with its experimental counterpart. LES of forced ignition is then performed using flamelet fully detailed tabulated chemistry combined with presumed pdfs. Various scenarios of flame kernel development are analyzed and correlated with typical flow conditions observed in this burner. The correlations between, velocities and mixture fraction values at the sparking time and the success or failure of ignition, are then further discussed and analyzed. (author)

Subramanian, V.; Domingo, P.; Vervisch, L. [CORIA-CNRS and INSA de Rouen, Technopole du Madrillet, BP 8, 76801 Saint-Etienne-du-Rouvray (France)

2010-03-15T23:59:59.000Z

98

Fast Ignition  

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

ignition. The approach being taken by the National Ignition Facility to achieve thermonuclear ignition and burn is called the "central hot spot" scenario. This technique relies...

99

Development of an energy efficient curtain flame ignition system for sintering of iron ore fines  

Science Journals Connector (OSTI)

Research and Development Centre for Iron and Steel (RDCIS) of Steel Authority of India Limited (SAIL) has developed a 'curtain flame' ignition system for sinter mix ignition. Conventionally, either horizontal fired burners or top fired or a combination of both are used for ignition of sinter mix. These burners big in size but few in number are mounted on a rectangular box type furnace. This is associated with non-uniform heating of sinter mix. In the new system, small capacity burners are installed on the roof across the sinter bed in a single row. Here, the top layer of the sinter bed gets heated by the direct impingement of the flame. This has resulted in reduction in specific fuel gas consumption by more than 30% and savings in refractory consumption. Implementation of the system led to reduction in green house gas (GHG) emission also.

V.T. Selvan; T.S. Reddy; A. Das

2012-01-01T23:59:59.000Z

100

Advanced aircraft ignition CRADA final report  

SciTech Connect (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

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

Ignition and Flame Quenching of Quiescent Fuel Mists  

Science Journals Connector (OSTI)

...Ignition and Flame Quenching of Quiescent Fuel Mists D. R. Ballal A. H. Lefebvre A...the ignition of quiescent multidroplet fuel mists which assumes that chemical reaction...spark, of an adequate concentration of fuel vapour in the ignition zone. From analysis...

1978-01-01T23:59:59.000Z

102

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

103

Laser ignition  

DOE Patents [OSTI]

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

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

2002-01-01T23:59:59.000Z

104

Laser ignition  

DOE Patents [OSTI]

In the apparatus of the invention, a first excitation laser or other excitation light source is used in tandem with an ignitor laser to provide a compact, durable, engine deployable fuel ignition laser system. The beam from the excitation light source is split with a portion of it going to the ignitor laser and a second portion of it being recombined with the first portion after a delay before injection into the ignitor laser. 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.

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

2002-01-01T23:59:59.000Z

105

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

SciTech Connect (OSTI)

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

Stolz, C J

2007-10-15T23:59:59.000Z

106

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

E-Print Network [OSTI]

to electrical energy consumed to produce the discharge.) Consequently, ignition by laser sources has beenEFFECT OF FUEL TYPE ON FLAME IGNITION BY TRANSIENT PLASMA DISCHARGES Jianbang Liu1,2 , Fei Wang1 with air ignited by transient plasma discharge were investigated and compared with spark discharge ignition

107

Large discharge-volume, silent discharge spark plug  

DOE Patents [OSTI]

A large discharge-volume spark plug for providing self-limiting microdischarges. The apparatus includes a generally spark plug-shaped arrangement of a pair of electrodes, where either of the two coaxial electrodes is substantially shielded by a dielectric barrier from a direct discharge from the other electrode, the unshielded electrode and the dielectric barrier forming an annular volume in which self-terminating microdischarges occur when alternating high voltage is applied to the center electrode. The large area over which the discharges occur, and the large number of possible discharges within the period of an engine cycle, make the present silent discharge plasma spark plug suitable for use as an ignition source for engines. In the situation, where a single discharge is effective in causing ignition of the combustible gases, a conventional single-polarity, single-pulse, spark plug voltage supply may be used.

Kang, Michael (Los Alamos, NM)

1995-01-01T23:59:59.000Z

108

Laser Ignition  

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

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...

109

Laser ignition of hypersonic air–hydrogen flow  

Science Journals Connector (OSTI)

An experimental investigation of the behaviour of laser-induced ignition in a hypersonic air–hydrogen flow is ... /s. This study is the first comprehensive laser spark study in a hypersonic flow and demonstrates ...

S. Brieschenk; H. Kleine; S. O’Byrne

2013-09-01T23:59:59.000Z

110

Application of laser ignition on laminar flame front investigation  

Science Journals Connector (OSTI)

The first stages of laser-induced spark ignition were investigated as a function of time....4/air burner. Laser-induced breakdown was achieved by focusing a ... nanosecond pulse from a Q-switched Nd:YAG laser. An...

J.-L. Beduneau; Y. Ikeda

2004-01-01T23:59:59.000Z

111

Characterisation of laser ignition in hydrogen–air mixtures in a combustion bomb  

Science Journals Connector (OSTI)

Laser-induced spark ignition of lean hydrogen–air mixtures was experimentally investigated using nanosecond pulses generated by Q-switched Nd:YAG laser (wavelength 1064 nm) at initial pressure of 3 MPa and temperature 323 K in a constant volume combustion chamber. Laser ignition has several advantages over conventional ignition systems especially in internal combustion engines, hence it is necessary to characterise the combustion phenomena from start of plasma formation to end of combustion. In the present experimental investigation, the formation of laser plasma by spontaneous emission technique and subsequently developing flame kernel was measured. Initially, the plasma propagates towards the incoming laser. This backward moving plasma (towards the focusing lens) grows much faster than the forward moving plasma (along the direction of laser). A piezoelectric pressure transducer was used to measure the pressure rise in the combustion chamber. Hydrogen–air mixtures were also ignited using a spark plug under identical experimental conditions and results are compared with the laser ignition ones.

Dhananjay Kumar Srivastava; Martin Weinrotter; Kurt Iskra; Avinash Kumar Agarwal; Ernst Wintner

2009-01-01T23:59:59.000Z

112

Laser ignition  

DOE Patents [OSTI]

In the apparatus of the invention, a first excitation laser or other excitation light source is used in tandem with an ignitor laser to provide a compact, durable, engine deployable fuel ignition laser system. Reliable fuel ignition is provided over a wide range of fuel conditions by using a single remote excitation light source for one or more small lasers located proximate to one or more fuel combustion zones. In the embodiment of the invention claimed herein, the beam from the excitation light source is split with a portion of it going to the ignitor laser and a second portion of it being combined with either the first portion after a delay before injection into the ignitor laser.

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

2002-01-01T23:59:59.000Z

113

Laser ignition  

DOE Patents [OSTI]

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

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

2003-01-01T23:59:59.000Z

114

Effect of focal size on the laser ignition of compressed natural gas–air mixture  

Science Journals Connector (OSTI)

Abstract Laser ignition of compressed natural gas–air mixtures was investigated in a constant volume combustion chamber (CVCC) as well as in a single cylinder engine. Laser ignition has several potential advantages over conventional spark ignition system. Laser ignition relies on the fact that optical breakdown (plasma generation) in gases occurs at high intensities of ?1011 W/cm2. Such high intensities can be achieved by focusing a pulsed laser beam to small focal sizes. The focal spot size depends on several parameters such as laser wavelength, beam diameter at the converging lens, beam quality and focal length. In this investigation, the focal length of the converging lens and the beam quality were varied and the corresponding effects on minimum ignition energy as well as pressure rise were recorded. The flame kernel was visualized and correlated with the rate of pressure rise inside the combustion chamber. This investigation will be helpful in the optimization of laser and optics parameters in laser ignition. It was found that beam quality factor and focal length of focusing lens have a strong impact on the minimum ignition energy required for combustion. Combustion duration depends on the energy density at the focal spot and size of the flame kernel.

Dhananjay Kumar Srivastava; Ernst Wintner; Avinash Kumar Agarwal

2014-01-01T23:59:59.000Z

115

Target Diagnostic Control System Implementation for the National Ignition Facility  

SciTech Connect (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

116

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...

Suter, William Gregory

2012-06-07T23:59:59.000Z

117

Potassium-Calcium Exchange in a Multireactive Soil System: II. Thermodynamics1 P. M. JARDINE ANDD. L. SPARKS2  

E-Print Network [OSTI]

ions and sup- ports the hypothesis of the multireactive natureof the soil. Although K was selectively energy of ex- change, enthalpy of exchange, entropy of exchange. Jardine, P.M., and D.L. Sparks. 1984

Sparks, Donald L.

118

Control System For Cryogenic THD Layering At The National Ignition Facility  

SciTech Connect (OSTI)

The National Ignition Facility (NIF) is the world largest and most energetic laser system for Inertial Confinement Fusion (ICF). In 2010, NIF began ignition experiments using cryogenically cooled targets containing layers of the tritium-hydrogen-deuterium (THD) fuel. The 75 {micro}m thick layer is formed inside of the 2 mm target capsule at temperatures of approximately 18 K. The ICF target designs require sub-micron smoothness of the THD ice layers. Formation of such layers is still an active research area, requiring a flexible control system capable of executing the evolving layering protocols. This task is performed by the Cryogenic Target Subsystem (CTS) of the NIF Integrated Computer Control System (ICCS). The CTS provides cryogenic temperature control with the 1 mK resolution required for beta-layering and for the thermal gradient fill of the capsule. The CTS also includes a 3-axis x-ray radiography engine for phase contrast imaging of the ice layers inside of the plastic and beryllium capsules. In addition to automatic control engines, CTS is integrated with the Matlab interactive programming environment to allow flexibility in experimental layering protocols. The CTS Layering Matlab Toolbox provides the tools for layer image analysis, system characterization and cryogenic control. The CTS Layering Report tool generates qualification metrics of the layers, such as concentricity of the layer and roughness of the growth boundary grooves. The CTS activities are automatically coordinated with other NIF controls in the carefully orchestrated NIF Shot Sequence.

Fedorov, M; Blubaugh, J; Edwards, O; Mauvais, M; Sanchez, R; Wilson, B

2011-03-18T23:59:59.000Z

119

IGNITION IMPROVEMENT OF LEAN NATURAL GAS MIXTURES  

SciTech Connect (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

120

Spark-safe low-voltage detonator  

DOE Patents [OSTI]

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

Lieberman, Morton L. (Albuquerque, NM)

1989-01-01T23:59:59.000Z

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.


121

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

SciTech Connect (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, 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

122

Laser Ignition in Internal Combustion Engines - A Novel Approach Based on Advanced Lasers  

Science Journals Connector (OSTI)

Advantages of laser ignition compared to spark plugs are illustrated. Experiments involving optimized optics and passively Q-switched remotely diode-pumped mJ-Nd:YAG laser have been...

Weinrotter, Martin; Kopecek, Herbert; Wintner, Ernst

123

Laser Fusion — High Density Compression Experiment and Ignition Program with Gekko XII  

Science Journals Connector (OSTI)

High density compression of main fuel and stable formation of hot spark at the center of imploded core have been investigated to obtain the scaling and the requirements for fusion ignition and high gain. For t...

S. Nakai; K. Mima; H. Azechi; N. Miyanaga…

1992-01-01T23:59:59.000Z

124

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

SciTech Connect (OSTI)

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

125

COTTON WEED MANAGEMENT SYSTEMS WITH IGNITE. P. A. Dotray, T. A. Baughman, K.M McCormick, and J. W. Keeling. Texas Tech University, Lubbock; Texas Agricultural Experiment Station, Lubbock;  

E-Print Network [OSTI]

COTTON WEED MANAGEMENT SYSTEMS WITH IGNITE. P. A. Dotray, T. A. Baughman, K.M McCormick, and J. WLink cotton will be an option for growers in 2004. Ignite is a postemergence herbicide that has broad that has limited systemic movement in plants. Previous studies have shown that cotton tolerance to Ignite

Mukhtar, Saqib

126

Ignition Experiments  

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

Ignition Experiments The goal of many NIF experiments is to create a self-sustaining "burn" of fusion fuel (the hydrogen isotopes deuterium and tritium) that produces as much or...

127

Ignition reactor and pump pulse parameters in a reactor–laser system  

Science Journals Connector (OSTI)

The experience gained in operating a demonstration nuclear-pumped laser in stand B (Physics and Power- Engineering Institute (FEI)) with a pulsed ignition reactor based on the 235U BARS-6 reactor is analyzed. It ...

P. P. D’yachenko; G. N. Fokin

2012-09-01T23:59:59.000Z

128

Multi-strike ignition to improve performance, reduce misfiring of large gas engines  

SciTech Connect (OSTI)

New product and application information is now available on the advanced `CPU-2OOO` digital ignition system introduced by Altronic earlier this year for large-bore gas engines and integral compressors. The system is designed to improve performance, reduce misfiring, and be easily retrofitted to existing large-bore engines. including those that are being converted to lean-burn combustion in order to reduce emissions. To do this, the CPU-2OOO system features a selectable multi-striking mode, a selectable energy level and second spark plug cut-off control, a choice of global or individual cylinder timing control, and a high-energy long-duration spark. The 24 Vdc-powered system also offers comprehensive display and communications capabilities, plus system diagnostics and self-test functions. The system uses existing Altronic II-CPU coils, pickups, primary wiring harnesses and other hardware, allowing for easy upgrades of existing II-CPU installations. Also, a detonation avoidance system is being developed as an option for engine protection. Altronic says the field tests have demonstrated the ability of the CPU-20OO system to ignite extra-lean mixtures created when turbochargers are added to engines that previously operated at much richer levels. NO{sub x} emissions have been reduced by as much as 88%, to less than 2.7 g/kWh.

NONE

1995-10-01T23:59:59.000Z

129

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

SciTech Connect (OSTI)

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

130

National Ignition Facility & Photon Science What  

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

What is NiF? the national ignition Facility: bringing star Power to earth The National Ignition Facility (NIF) is the world's largest and highest energy laser system. NIF is an...

131

Fast Ignition Program Presented at  

E-Print Network [OSTI]

Laser drive Direct Laser drive #12;Fast Ignition may allow longer wavelength laser implosion systemsFast Ignition Program Presented at FESAC Development Path Panel General Atomics January 14, 2003 E. Michael Campbell ·Promise ·Status ·Challenges ·Implementation ·Plan #12;The original FI concept uses laser

132

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

E-Print Network [OSTI]

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

Paris-Sud XI, Université de

133

Using SPARK as a Solver for Modelica  

SciTech Connect (OSTI)

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

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

2008-06-30T23:59:59.000Z

134

A polar-drive shock-ignition design for the National Ignition Facility  

SciTech Connect (OSTI)

Shock ignition [R. Betti et al., Phys. Rev. Lett. 98, 155001 (2007)] is being pursued as a viable option to achieve ignition on the National Ignition Facility (NIF). Shock-ignition target designs use a high-intensity laser spike at the end of a low-adiabat assembly pulse to launch a spherically convergent strong shock to ignite the hot spot of an imploding capsule. A shock-ignition target design for the NIF is presented. One-dimensional simulations indicate an ignition threshold factor of 4.1 with a gain of 58. A polar-drive beam-pointing configuration for shock-ignition experiments on the NIF at 750 kJ is proposed. The capsule design is shown to be robust to the various one- and two-dimensional effects and nonuniformities anticipated on the NIF. The target is predicted to ignite with a gain of 38 when including all anticipated levels of nonuniformity and system uncertainty.

Anderson, K. S.; McKenty, P. W.; Collins, T. J. B.; Craxton, R. S.; Delettrez, J. A.; Marozas, J. A.; Skupsky, S.; Shvydky, A. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States)] [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States); Betti, R. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States) [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States); Fusion Science Center, University of Rochester, Rochester, New York 14623 (United States); Departments of Mechanical Engineering and Physics, University of Rochester, Rochester, New York 14627 (United States); Hohenberger, M.; Theobald, W.; Lafon, M.; Nora, R. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States) [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States); Fusion Science Center, University of Rochester, Rochester, New York 14623 (United States)

2013-05-15T23:59:59.000Z

135

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

SciTech Connect (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

136

Achievement of stable and clean combustion over a wide operating range in a spark-assisted IDI diesel engine with neat ethanol  

SciTech Connect (OSTI)

Spark-assisted diesel engines operated with alcohol fuels usually display misfiring or knocking problems. This paper presents an analysis of the factors influencing the ignition characteristics of ethanol in a swirl chamber diesel engine with a multi-spark ignitor. In the experiments, cycle-to-cycle combustion variations and the degree of knocking were investigated by changing engine parameters over a wide operating range. The results of the investigations showed that stable ignition and smooth combustion is achieved when a flammable mixture is formed in the vicinity of the spark plug when only a small amount of the injected fuel has evaporated.

Murayama, T.; Ogawa, H.; Miyamoto, N.; Chikahisa, T.

1984-01-01T23:59:59.000Z

137

SPARK! 2012 | ornl.gov  

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

Magnetic Filtration Process - Sherrill Advanced Credentialing For Trusted Networks - Sims Content Recommendation Solution - Tech Info Consumers - Morris Spark 2012 Request For...

138

SPARK! 2013 | ornl.gov  

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

139

Simulation of turbulent flames relevant to spark-ignition engines  

E-Print Network [OSTI]

- merous interesting and fruitful discussions. In addition, the comput- ing help I received from Mr Peter Benie and the staff at the Cambridge High Performance Computing Service is gratefully acknowledged. This work would not have been possible without...

Ahmed, Irufan

2014-04-29T23:59:59.000Z

140

Advanced Lean-Burn DI Spark Ignition Fuels Research  

Broader source: Energy.gov [DOE]

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

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

Advanced Lean-Burn DI Spark Ignition Fuels Research  

Broader source: Energy.gov [DOE]

2011 DOE Hydrogen and Fuel Cells Program, and Vehicle Technologies Program Annual Merit Review and Peer Evaluation

142

End gas autoignition and knock in a spark ignition engine  

SciTech Connect (OSTI)

The paper is concerned with end-gas autoignition, subsequent knock severity and magnitude of induced gas velocity. An optically accessed single cylinder two stroke engine was modified to give complete overhead optical access to the disc-shaped combustion chamber. Flame propagation and end-gas autoignition events were recorded using high speed natural light and schlieren photography; local gas motions, prior to and induced by the knock event, were determined using an oil droplet trajectory technique. Cylinder pressure was synchronously recorded at three positions around the cylinder head; one transducer's output being simultaneously displayed on the film. End gas autoignition generally developed from multiple centers. Autoignition was usually, but not invariably, followed by knock. The severity of knock increased as the onset of autoignition occurred closer behind the top dead centre position; knock was characterized by pressure oscillations, carbon formation and high velocity post-knock gas motions. These phenomena were relatively insensitive to mass fraction unburned at the time of autoignition.

Konig, G.; Sheppard, C.G.W.

1990-01-01T23:59:59.000Z

143

Advanced Lean-Burn DI Spark Ignition Fuels Research  

Broader source: Energy.gov [DOE]

2012 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting

144

Crevice volume effect on spark ignition engine efficiency  

E-Print Network [OSTI]

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

Smith, Patrick M. (Patrick Michael)

2013-01-01T23:59:59.000Z

145

Improving the Efficiency of Spark Ignited, Stoichiometric Natural Gas Engines  

Broader source: Energy.gov [DOE]

This work focused on using camless engine technology to improve the efficiency of a natural gas engine. Late intake close timing and cylinder deactivation were utilized to meet a peak BTE > 40%.

146

Special Feature: Energy - The Spark that Ignited DOE Supercomputing  

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

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

147

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

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

- A Fuel Economy Solution for The US Turbocharged SIDI is the most promising advanced gasoline technology; combines existing & proven technologies in a synergistic manner, offers...

148

Pressure-wave supercharged spark-ignition engines  

Science Journals Connector (OSTI)

The modern generation of pressure-wave supercharger (PWS) called Hyprex offers a new approach for supercharging gasoline engines. This type of PWS has the potential to replace complex and costly two-stage supe...

Lucas Flückiger; Stephan Tafel; Peter Spring

2006-12-01T23:59:59.000Z

149

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

E-Print Network [OSTI]

as a step towards laser fusion ignition, Nature, 412 (2001),tip. Full scale fast ignition laser systems are envisionedmodified. Full scale fast ignition laser systems of 100 kJ

Ma, Tammy Yee Wing

2010-01-01T23:59:59.000Z

150

Coke-free dry reforming of model diesel fuel by a pulsed spark plasma at low temperatures using an exhaust gas recirculation (EGR) system  

Science Journals Connector (OSTI)

Dry reforming of diesel fuel, an endothermic reaction, is an attractive process for on-board hydrogen/syngas production to increase energy efficiency. For operating this dry reforming process in a vehicle, we can use the exhaust gas from an exhaust gas recirculation (EGR) system as a source of carbon dioxide. Catalytic dry reforming of heavy hydrocarbon is a very difficult reaction due to the high accumulation of carbon on the catalyst. Therefore, we attempted to use a non-equilibrium pulsed plasma for the dry reforming of model diesel fuel without a catalyst. We investigated dry reforming of model diesel fuel (n-dodecane) with a low-energy pulsed spark plasma, which is a kind of non-equilibrium plasma at a low temperature of 523?K. Through the reaction, we were able to obtain syngas (hydrogen and carbon monoxide) and a small amount of C2 hydrocarbon without coke formation at a ratio of CO2/Cfuel = 1.5 or higher. The reaction can be conducted at very low temperatures such as 523?K. Therefore, it is anticipated as a novel and effective process for on-board syngas production from diesel fuel using an EGR system.

Yasushi Sekine; Naotsugu Furukawa; Masahiko Matsukata; Eiichi Kikuchi

2011-01-01T23:59:59.000Z

151

National Ignition Facility & Photon Science NIF AT A GLANCe  

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

& Photon Science NIF AT A GLANCe the national ignition Facility at a glance The National Ignition Facility (NIF) is the world's largest laser system, housed in a 10-story building...

152

Thermonuclear Ignition of Dark Galaxies  

E-Print Network [OSTI]

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

J. Marvin Herndon

2006-01-01T23:59:59.000Z

153

Tantalum–tungsten oxide thermite composites prepared by sol–gel synthesis and spark plasma sintering  

Science Journals Connector (OSTI)

Energetic composite powders consisting of sol–gel derived nanostructured tungsten oxide were produced with various amounts of micrometer-scale tantalum fuel metal. Such energetic composite powders were ignition-tested and the results show that the powders are not sensitive to friction, spark and/or impact ignition. Initial consolidation experiments, using the High-Pressure Spark Plasma Sintering (HPSPS) technique, on the sol–gel derived nanostructured tungsten oxide produced samples with higher relative density than can be achieved with commercially available tungsten oxide. The sol–gel derived nanostructured tungsten oxide with immobilized tantalum fuel metal (Ta–WO3) energetic composite was consolidated to a density of 9.17 g cm?3 or 93% relative density. In addition, those samples were consolidated without significant pre-reaction of the constituents, thus retaining their stored chemical energy.

Joshua D. Kuntz; Octavio G. Cervantes; Alexander E. Gash; Zuhair A. Munir

2010-01-01T23:59:59.000Z

154

Resistance of a water spark.  

SciTech Connect (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

155

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

156

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. 11 figs.

Early, J.W.

1999-03-02T23:59:59.000Z

157

Status of the National Ignition Campaign Prof. R. Paul Drake  

E-Print Network [OSTI]

Ignition Campaign has the goal of producing net en- ergy gain in a laser-fusion system. I have been keeping Status of the National Ignition Campaign Prof. R. Paul Drake Joint Seminar with Atmospheric progress on the National Ignition Campaign, from a recent conference. This includes a discussion

Shyy, Wei

158

Efficiency Analysis of Natural Gas Residential Micro-cogeneration Systems  

Science Journals Connector (OSTI)

The systems feature different energy conversion technologies: Stirling engine (WhisperGen), spark-ignition internal combustion (IC) engine (FreeWatt), and polymer electrolyte fuel cell (PEFC) (EBARA Ballard). ... The Stirling engine is the least expensive that requires the least maintenance. ... Experimental Determination of the Efficiency and Emissions of a Residential Microcogeneration System Based on a Stirling Engine and Fueled by Diesel and Ethanol ...

Amir A. Aliabadi; Murray J. Thomson; James S. Wallace

2010-01-22T23:59:59.000Z

159

Ignition problems in scramjet testing  

SciTech Connect (OSTI)

Ignition of H{sub 2} in heated air containing H{sub 2}O, radicals, and dust was investigated for scramjet testing. Using a reduced kinetic model for H{sub 2}{minus}O{sub 2} systems, the effects of H{sub 2}O and radicals in nozzles are discussed in relation to engine testing with vitiation heaters. Analysis using linearized rate-equations suggested that the addition of O atoms was 1.5 times more effective than the addition of H atoms for ignition. This result can be applied to the problem of premature ignition caused by residual radicals and to plasma-jet igniters. Thermal and chemical effects of dust, inevitable in storage air heaters, were studied next. The effects of heat capacity and size of dust were expressed in terms of an exponential integral function. It was found that the radical termination on the surface of dust produces an effect equivalent to heat loss. The inhibition of ignition by dust may result, if the mass fraction of dust becomes 10{sup {minus}3}.

Mitani, Tohru [National Aerospace Lab., Miyagi (Japan)] [National Aerospace Lab., Miyagi (Japan)

1995-05-01T23:59:59.000Z

160

Confinement of ignition and yield on the National Ignition Facility  

SciTech Connect (OSTI)

The National Ignition Facility Target Areas and Experimental Systems has reached mid-Title I design. Performance requirements for the Target Area are reviewed and design changes since the Conceptual Design Report are discussed. Development activities confirm a 5-m radius chamber and the viability of a boron carbide first wall. A scheme for cryogenic target integration with the NIF Target Area is presented.

Tobin, M.; Karpenko, V.; Foley, D.; Anderson, A.; Burnham, A.; Reitz, T.; Latkowski, J.; Bernat, T.

1996-06-14T23:59:59.000Z

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.


161

Predictive Modeling of a Homogeneous Charge Compression Ignition (HCCI) Engine with EGR Fueled with Diesel  

Science Journals Connector (OSTI)

Homogeneous charge compression ignition (HCCI) combustion integrates features of both spark ignition (SI) and compression ignition (CI) engines, obtaining a promisingly high efficiency in a diesel engine with virtually almost no NOx and soot emissions. ... The objective of the model is to simulate fundamental engine results such as combustion pressure, heat-release rate, indicated mean pressure (IMEP), gas temperature, and exhaust gas emission from easily measured engine parameters. ... Gordon, P. B. The Design and Simulation of a 4 Stroke Engine; Society of Automotive Engineers: Warrendale, PA, 1999. ...

Miguel Torres García; Fco Jiménez-Espadafor Aguilar; Elisa Carvajal Trujillo; José Antonio Becerra Villanueva

2009-09-10T23:59:59.000Z

162

Laser-induced ignition by optical breakdown  

Science Journals Connector (OSTI)

This paper is an experimental work of the applied methodical character in which as an attempt to optimize a laser ignition system a systematic study of the best incoupling geometry for the employed Nd:YAG laser w...

E. Schwarz; I. Muri; J. Tauer; H. Kofler; E. Wintner

2010-06-01T23:59:59.000Z

163

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

SciTech Connect (OSTI)

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

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

1998-08-01T23:59:59.000Z

164

Target area acquisition and control system survivability for the National Ignition Facility  

SciTech Connect (OSTI)

The hardening of instruments to survive NIF target emission environments presents a significant challenge. Neutron flux is predicted to be as much as six orders of magnitude greater than the highest achieved neutron flux on NOVA. Not withstanding the high prompt radiation fields, the specifications for the instruments are demanding; requiring high resolution imaging and sub nanosecond transient measurements. We present an analysis of the sensitivity of the proposed NIF instrumentation design to EMP, X-rays, gamma rays, and neutrons. Major components assessed include fiber optic cable transport, high bandwidth cable and charge coupled detector (CCD) imaging systems.

Hagans, K.; Stathis, P.; Wiedwald, J.; Campbell, D.

1994-06-01T23:59:59.000Z

165

AIR QUALITY REPORT SPARKS CONTROVERSY  

Science Journals Connector (OSTI)

AIR QUALITY REPORT SPARKS CONTROVERSY ... The National Commission on Air Quality delivered its eagerly awaited report to Congress today, and reaction from industry and environmental groups is expected to be both swift and sharp. ... Created under the 1977 Clean Air Act, the commission was charged with assessing the effectiveness of the law, and recommending changes where the law falls short of achieving the goal of improving the nation's air quality. ...

1981-03-02T23:59:59.000Z

166

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

SciTech Connect (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

167

The use of auxiliary ignition devices to improve combustion of low centane-high volatility fuels in a diesel engine  

SciTech Connect (OSTI)

The use of auxiliary ignition devices to improve the combustion of low cetane-high volatility fuels in a Diesel engine is described. Previous combustion with a low cetane-high volatility fuel (with a spark plug located at the periphery of the cylinder) resulted in engine knock at heavy loads and poor engine operation at light loads. In the present investigation, several new ignition devices were used to ignite the fuel in the center of the cylinder, to allow combustion to be controlled by rate of injection. The devices used were an extended spark electrode, a fuel spray deflector, a nozzle glow ring, and a nozzle fuel cage. High speed photography and heat release were used to characterize the ignition and combustion process of the low cetane fuel in conjunction with the ignition devices. Combustion with all of the ignition devices was initiated in the center of the cylinder, significantly reducing engine knock. The use of the auxiliary ignition devices to ignite the fuel in the center of the chamber demonstrated extended operation of the Diesel engine for all of the devices tested.

Stroia, B.L.; Abata. D.L.

1988-01-01T23:59:59.000Z

168

Achievement of stable and clean combustion over a wide operating range in a spark-assisted IDI diesel engine with neat ethanol  

SciTech Connect (OSTI)

Spark-assisted diesel engines operated with alcohol fuels usually display misfiring or knocking problems. This paper presents an analysis of the factors influencing the ignition characteristics of ethanol in a swirl chamber diesel engine with a multi-spark ignitor. In the experiments, cycle-to-cycle combustion variations and the degree of knocking were investigated by changing engine parameters over a wide operating range. The results of the investigations showed that stable ignition and smooth combustion is achieved when a flammable mixture is formed in the vicinity of the spark plug when only a small amount of the injected fuel has evaporated. By optimizing the design factors, operation with high efficiency and low exhaust emissions was achieved.

Murayama, T.; Chikahisa, T.; Miyamoto, N.; Ogawa, H.

1984-02-01T23:59:59.000Z

169

Effects of temperature on laser diode ignition  

Science Journals Connector (OSTI)

In this paper, the effects of temperature on laser diode ignition and the resulting consequences were discussed in detail through theoretical analysis, experiments and numerical calculations. The results indicated that the output power of laser diode decreases and the wavelength of laser redshifts with elevated working temperature under a certain condition. The threshold conditions of ignition for powders are easily satisfied with increase in ambient temperature. While the temperature reaches a high enough level, ignition can occur and also the self-combustion or thermal induced explosion can do, even if laser power is very low. Therefore, it is of great importance to carefully control the working temperature of laser diode and the ambient temperature of powder system, and in the meanwhile, to install necessary insurance apparatus in order to ensure the normal and safe operation of the ignition system.

Shi-Biao Xiang; Xu Xiang; Chang-Gen Feng

2009-01-01T23:59:59.000Z

170

A photographic study of the combustion of low cetane fuels in a Diesel engine aided with spark assist  

SciTech Connect (OSTI)

An experimental investigation of the ignition and combustion characteristics of two low cetane fuels in a spark assisted Diesel engine is described. A three cylinder Diesel engine was modified for single cylinder operation and fitted with a spark plug located in the periphery of the spray plume. Optical observations of ignition and combustion were obtained with high speed photography. Optical access was provided by a quartz piston crown and extended head arrangement. The low cetane fuels, a light end, low viscosity fuel and a heavy end, high viscosity fuel which were blended to bracket No. 2 Diesel fuel on the distillation curve, demonstrated extended operation in the modified Diesel engine. Qualitative and quantitative experimental observations of ignition delay, pressure rise, heat release, spray penetration and geometery were compared and evaluated against theoretical predictions. Results indicate that controlled combustion of extended fuel blends in a Diesel engine may be possible without inlet air preconditioning and that engine knock may be avoided when heat release is optimized with proper spark and injection timing.

Abata, D.L.; Fritz, S.G.; Stroia, B.J.

1986-01-01T23:59:59.000Z

171

Spark Green Energy Pvt Ltd | Open Energy Information  

Open Energy Info (EERE)

Spark Green Energy Pvt Ltd. Place: Mumbai, Maharashtra, India Zip: 400 050 Sector: Biomass Product: Mumbai-based biomass project developer. References: Spark Green Energy Pvt...

172

Alternative Fuels Data Center: Partnerships Spark Biodiesel Success for  

Alternative Fuels and Advanced Vehicles Data Center [Office of Energy Efficiency and Renewable Energy (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

173

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

174

Laser ignition studies  

SciTech Connect (OSTI)

The goal of this work is to study the details of laser induced ignition and combustion of high-temperature condensed-phase exothermic reactions. In this work high-speed photography (HSP) and real-time optical pyrometry have been combined to provide a diagnostic tool with a 1 ms temporal resolution for studying laser ignition and combustion wave propagation. Previous experiments have involved the use of HSP for studying combustion wave propagation (1) Real-time pyrometry studies of the ignition process have also been performed previously. The present paper describes how HSP has been expanded to include three-view split-frame photography to allow the ignition and combustion processes to be recorded and studied simultaneously. 2 refs., 3 figs.

Fredin, L.; Hansen, G.P.; Margrave, J.L.; Behrens, R.G.

1985-10-01T23:59:59.000Z

175

Groundbreaking at National Ignition Facility | National Nuclear...  

National Nuclear Security Administration (NNSA)

Ignition Facility May 29, 1997 Groundbreaking at National Ignition Facility Livermore, CA Secretary Pena participates in the ground breaking ceremony for the National Ignition...

176

Multidimensional modeling of diesel ignition and combustion using a multistep kinetics model  

SciTech Connect (OSTI)

Ignition and combustion mechanisms in diesel engines were studied using the KIVA code, with modifications to the combustion, heat transfer, crevice flow, and spray models. A laminar-and-turbulent characteristic-time combustion model that has been used successfully for spark-ignited engine studies was extended to allow predictions of ignition and combustion in diesel engines. A more accurate prediction of ignition delay was achieved by using a multistep chemical kinetics model. The Shell knock model was implemented for this purpose and was found to be capable of predicting successfully the autoignition of homogeneous mixtures in a rapid compression machine and diesel spray ignition under engine conditions. The physical significance of the model parameters is discussed and the sensitivity of results to the model constants is assessed. The ignition kinetics model was also applied to simulate the ignition process in a Cummins diesel engine. The post-ignition combustion was simulated using both a single-step Arrhenius kinetics model and also the characteristic-time model to account for the energy release during the mixing-controlled combustion phase. The present model differs from that used in earlier multidimensional computations of diesel ignition in that it also includes state-of-the-art turbulence and spray atomization models. In addition, in this study the model predictions are compared to engine data. It is found that good levels of agreement with the experimental data are obtained using the multistep chemical kinetics model for diesel ignition modeling. However, further study is needed of the effects of turbulent mixing on post-ignition combustion.

Kong, S.C.; Reitz, R.D. (Univ. of Wisconsin, Madison, WI (United States). Dept. of Mechanical Engineering)

1993-10-01T23:59:59.000Z

177

The National Ignition Facility: A New Era in High Energy Density Science  

SciTech Connect (OSTI)

The National Ignition Facility, the world's most energetic laser system, is now operational. This talk will describe NIF, the ignition campaign, and new opportunities in fusion energy and high energy density science enabled by NIF.

Moses, E

2009-06-10T23:59:59.000Z

178

Laser ignition of flammable mixtures via a solid core optical fiber  

Science Journals Connector (OSTI)

To date no commercial fiber coupled laser systems have reached the irradiance and pulse energy required for flammable mixtures ignition. In this work we report preliminary results on the ignition of two-phase mix...

H. El-Rabii; G. Gaborel

2007-03-01T23:59:59.000Z

179

Laser-induced plasma ignition studies in a model scramjet engine  

Science Journals Connector (OSTI)

An experimental investigation of the behavior of laser-induced plasma (LIP) ignition for scramjet inlet injection is presented. The presented results demonstrate for the first time, that LIP can be used to promote the formation of hydroxyl in a hypersonic flow. The temporal evolution of the LIP-ignited region is monitored using the planar laser-induced fluorescence technique on the hydroxyl radical. This study is the first laser spark study in a hypersonic flow, shown to generate combustion products where they would not otherwise occur.

Stefan Brieschenk; Sean O’Byrne; Harald Kleine

2013-01-01T23:59:59.000Z

180

Progress Toward Ignition on the National Ignition Facility  

SciTech Connect (OSTI)

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

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

National Ignition Facility & Photon Science  

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

5 National Ignition Facility & Photon Science how do Lasers work? how Do Lasers work? A laser can be as small as a microscopic computer chip or as immense as the National Ignition...

182

Using SPARK as a Solver for Modelica  

E-Print Network [OSTI]

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

Wetter, Michael

2008-01-01T23:59:59.000Z

183

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

184

Review of the National Ignition Campaign 2009-2012  

SciTech Connect (OSTI)

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

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

2014-02-15T23:59:59.000Z

185

ArcSafe® with Pulsed Arrested Spark Discharge  

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

186

Target Visualization at the National Ignition Facility  

SciTech Connect (OSTI)

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

187

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;Target chamber #12;Target chamber national geographic #12;Target chamber inside #12;Warehouse of laser

188

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

SciTech Connect (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). 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

189

COLLOQUIUM: In Pursuit of Ignition on the National Ignition Facility...  

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

the Lawrence Livermore National Laboratory with the goal of igniting a propagating thermonuclear burn wave in DT fuel leading to energy gain (defined as fusion yieldinput laser...

190

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 References: EIA Form EIA-861 Final Data File for 2010 - File220101 EIA Form 861...

191

A spark chamber for cosmic ray research  

E-Print Network [OSTI]

11. The triggered 'park gap. f 1 29 ;"'he t" igger elec. :ode i a polished 7-mi turgs ~en wire. I+ i he' d t-ut in a Plex' glas frame ard. Positioncdhs, fway bet- ween the spark g p electrodes. The wir e is thus in the equipoten? tia p ane... 11. The triggered 'park gap. f 1 29 ;"'he t" igger elec. :ode i a polished 7-mi turgs ~en wire. I+ i he' d t-ut in a Plex' glas frame ard. Positioncdhs, fway bet- ween the spark g p electrodes. The wir e is thus in the equipoten? tia p ane...

Jelinek, Al Vincent

2012-06-07T23:59:59.000Z

192

Central ignition scenarios for TFTR  

SciTech Connect (OSTI)

The possibility of obtaining ignition in TFTR by means of very centrally peaked density profiles is examined. It is shown that local central alpha heating can be made to exceed local central energy losses (''central ignition'') under global conditions for which Q greater than or equal to 1. Time dependent 1-D transport simulations show that the normal global ignition requirements are substantially relaxed for plasmas with peaked density profiles. 18 refs., 18 figs.

Zweben, S.J.; Redi, M.H.; Bateman, G.

1986-03-01T23:59:59.000Z

193

Ignition enhancement for scramjet combustion.  

E-Print Network [OSTI]

??The process of shock-induced ignition has been investigated both computa- tionally and experimentally, with particular emphasis on the concept of radical farming. The first component… (more)

McGuire, Jeffrey Robert

2007-01-01T23:59:59.000Z

194

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

SciTech Connect (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} (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

195

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

SciTech Connect (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

196

Laser Ignition of Single Magnesium Particles  

Science Journals Connector (OSTI)

The minimum ignition temperature and minimum ignition energy of single magnesium particles was determined ... levitated ultrasonically and was ignited by a short laser pulse. The temperature transient of the part...

J. F. Zevenbergen; A. E. Dahoe…

2000-01-01T23:59:59.000Z

197

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

198

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

199

Princeton Plasma Physics Lab - National Ignition Facility  

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

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

200

Ignition on the National Ignition Facility: a path towards inertial fusion energy  

Science Journals Connector (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 nearing completion at Lawrence Livermore National Laboratory (LLNL). 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. The NIF project is scheduled for completion in March 2009. Currently, all 192 beams have been operationally qualified and have produced over 4.0?MJ of light at the fundamental wavelength of 1053?nm, making NIF the world's first megajoule laser. 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 scientific applications.The plan is to begin 96-beam symmetric indirect-drive ICF experiments early in FY2009. These first experiments represent the next phase of the National Ignition Campaign (NIC). This national effort to achieve fusion ignition is coordinated through a detailed plan that includes the science, technology and equipment such as diagnostics, cryogenic target manipulator and user optics required for ignition experiments. Participants in this effort include LLNL, General Atomics, Los Alamos National Laboratory, Sandia National Laboratory 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 soon after project completion and to conduct a credible ignition campaign in 2010. When the NIF is complete, the long-sought goal of achieving self-sustaining nuclear fusion and energy gain in the laboratory will be 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 (Lindl 1998 Inertial Confinement Fusion: the Quest for Ignition and Energy Gain Using Indirect Drive (New York: American Institute of Physics)) and has a 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 (Tabak et al 1994 Phys. Plasmas 1 1626–34, Tabak et al 2005 Phys. Plasmas 12 057305). Moreover, NIF will have important scientific applications in such diverse fields as astrophysics, nuclear physics and materials science.This paper summarizes the design, performance and status of NIF, experimental plans for NIC, and will present laser inertial confinement fusion–fission energy (LIFE) as a path to achieve carbon-free sustainable energy.

Edward I. Moses

2009-01-01T23:59:59.000Z

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.


201

Feasibility study of a 6V-92TA homogeneous auto-ignited two-stroke (HAT) compressed-natural-gas-engine. Topical report, August 1989-May 1990  

SciTech Connect (OSTI)

The objective of the project was to modify a two-stroke 6V-92TA diesel engine to operate on natural gas using a simple system with gas addition to the compressor inlet and a spark plug for cold start and non-autoignition engine operation. The engine was to be operated at most speed-load conditions by autoignition of the premixed gas-air mixture. This concept is referred to as the Homogeneous Auto-Ignited Two-Stroke (HAT). Autoignition of carbureted natural gas was achieved at various loads and speeds in a 6V-92TA engine modified for operating on natural gas with the HAT concept. However, HAT engine operation up to 277 hp at 2100 rpm (diesel coach rating) was not achieved because early ignition in some cylinders caused knock and excessive heat transfer. Instead, the engine was operated up to 226 hp (767 N.m) at 2100 rpm, 181 hp (780 N.m) at 1650 rpm, 130 hp (773 N.m) at 1200 rpm, and 34 hp (368 N.m) at 650 rpm. Maximum brake thermal efficiency measured was 33.4% at 2100 rpm/219 hp. The corrected efficiency (to compensate for the unburned natural gas lost during the scavenging process) was higher than this. Steady-state emissions show very low NOx, total unburned HC lower than expected and reasonable CO levels. The lean air-fuel mixture and unburned exhaust gases in the cylinder resulted in very low NOx emissions.

Kakwani, R.M.; Winsor, R.E.

1990-08-01T23:59:59.000Z

202

System safety in Stirling engine development  

SciTech Connect (OSTI)

The Department of Energy has established a number of broad programs aimed at reducing highway fuel consumption. One of the programs addresses the Stirling engine propulsion system as a possible alternative to the conventional spark-ignition engine. The objective of this program is the development, by 1984, of a Stirling engine system having at least 30% improvement in fuel economy (mpg) over production vehicles powered by conventional spark-ignition engines of the same weight and performance, based on equal BTU content of fuel used. The DOE/NASA Stirling Engine Project Office has required that contractors make safety considerations an integral part of all phases of the Stirling engine development program. As an integral part of each engine design subtask, analyses are being evolved to determine possible modes of failure. The accepted system safety analysis techniques (Fault Tree, FMEA, Hazards Analysis, etc.) are being applied in various degrees of extent at the system, subsystem and component levels. The primary objectives are to identify critical failure areas, to enable removal of susceptibility to such failures or their effects from the system and to minimize risk.

Bankaitis, H.

1981-01-01T23:59:59.000Z

203

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

204

Ignition distributor voltage generator  

SciTech Connect (OSTI)

This patent describes a voltage pulse generator and ignition distributor comprising, a base, a shaft rotatably supported by the base, a distributor cap supported by the base having a center electrode and circumferentially spaced outer electrodes. The pulse generator and ignition distribution also include a first rotor driven by the shaft formed of electrical insulating material having electrically conductive means connected to the center terminal and a portion that rotates past the outer electrodes. The portion of the electrically conductive means that rotates past the outer electrodes is spaced from the outer electrodes to form a gap therebetween. A voltage pulse generator comprises a second rotor driven by the shaft, at least one permanent magnet and an annular pickup coil supported by the base. The pickup coil has inner turns and outer turns, the beginning turn of the inner turns connected to a first lead and the last turn of the outer turns connected to a second lead, the outer turns enclosing the inner turns. The pickup coil also has a circuit connected directly between the second lead and ground which is operative to provide a direct conductive path to ground for high frequency energy capacitively coupled to the outer turns from the gap discharge between the electrically conductive means of the first rotor and an outer electrode, the outer turns forming a grounded shield for the inner turns.

Boyer, J.A.

1986-11-04T23:59:59.000Z

205

Impact of cetane improvers on ignition delay times of several alternative biofuels  

SciTech Connect (OSTI)

Biofuel technology could be approaching one of its greatest development milestones--being accepted as a standard item on new vehicle technology. In particular, the Partnership for a New Generation Vehicle (PNGV) lists the evaluation and possible utilization of alternative fuels as one of the technological focuses to be evaluated by the year 2000. Synergy 2010, Ford`s newest Taurus model concept car, includes the use of a 20:1 compression-ratio, compression-ignition (CI) engine as the preferred engine. The preferred fuels include diesel, gasoline, and methanol. Cetane improvers make methanol fuel practical with a 20:1 compression ratio engine such as that proposed with Synergy 2010 and are a key technology for biofuel success. CI engines have a high probability of becoming the preferred engines for PNGV vehicles since CI engines are 20% to 30% more efficient than spark-ignition engines. In addition, CI engines allow a wider range of viable biofuels to be used. This paper is on the impact of cetane improvers on methanol and other biofuels. Fuels are evaluated through ignition delay time studies in a constant volume combustor. Ignition delay times measured at several temperatures and with biofuels of different compositions provide much more data than conventional cetane numbers and provide an understanding which is essential to engineer biofuels for the best possible performance in new engines. Ignition delay times are reported for several biofuels including mixtures containing biodiesel, methanol, and syrup.

Suppes, G.J. [Univ. of Kansas, Lawrence, KS (United States); Bryan, M.; Chen, Z. [and others

1996-12-31T23:59:59.000Z

206

Plastic ablator ignition capsule design for the National Ignition Facility  

SciTech Connect (OSTI)

This paper describes current efforts to develop a plastic ablator capsule design for the first ignition attempt on the National Ignition Facility. The trade-offs in capsule scale and laser energy that must be made to achieve ignition probabilities comparable to those with other candidate ablators, beryllium and high-density carbon, are emphasized. Large numbers of 1-D simulations, meant to assess the statistical behavior of the target design, as well as 2-D simulations to assess the target's susceptibility to Rayleigh-Taylor growth are discussed.

Clark, D S; Haan, S W; Hammel, B A; Salmonson, J D; Callahan, D A; Town, R J

2009-10-06T23:59:59.000Z

207

Monitoring system assists in dual-fuel engine knock prevention  

SciTech Connect (OSTI)

ABB Industrietechnik AG recently has introduced an augmented version of its Cyldeyt cylinder pressure monitoring system aimed at spark-ignited and diesel/gas, dual-fuel engines. In addition to recording and evaluating cylinder pressure as a means of assessing engine condition, the new Cyldet version now evaluates the cylinder pressure signals to provide protection against pre-ignition related damage. When pre-ignition reaches critical levels, the Cyldet computer relays alarm signals in two stages to the overriding engine control system of the power plant. On receiving the first-stage alarm signal, the engine control system is programmed to adjust one or more engine settings to eliminate preignition - a typical adjustment is to lower charge-air temperature, for example. If such measures fail to eliminate pre-ignition, in the case of a dual-fuel engine, a second alarm signal triggers a reduction in engine load or, as last resort, changeover of the engine to 100% diesel fuel charge. This paper outlines the advantages and applications of the system. 1 fig., 1 tab.

Not Available

1995-03-01T23:59:59.000Z

208

Advanced ignition options for laser ICF  

E-Print Network [OSTI]

Advanced ignition options for laser ICF FPA Meeting, Washington DC, December 1-3, 2010 R. Betti shock) · Fast Ignition requires major hardware upgrades: 100kJ-class multi-PW laser [also talk by P explore high-gain shock ignition - Polar Shock Ignition (uses half the NIF beams to drive the implosion

209

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

210

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

E-Print Network [OSTI]

indicated that turbocharger does not add considerably to the overall irreversibilities and combustion irreversibility is still the major source of exergy destruction. A comprehensive parametric investigation was also performed to investigate the effects...

Lawand, Vaibhav

2010-07-14T23:59:59.000Z

211

Performance of a spark ignition, lean burn, natural gas internal combustion engine .  

E-Print Network [OSTI]

??Relative to gasoline and diesel, use of natural gas as a transport fuel can produce significantly lower emissions of particulate matter and greenhouse gases. Future… (more)

ABBASI ATIBEH, PAYMAN

2012-01-01T23:59:59.000Z

212

Turbocharged Spark Ignited Direct Injection- A Fuel Economy Solution for The US  

Broader source: Energy.gov [DOE]

Turbocharged SIDI is the most promising advanced gasoline technology; combines existing & proven technologies in a synergistic manner, offers double digit fuel economy benefits, much lower cost than diesel or hybrid.

213

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

E-Print Network [OSTI]

. INTRODUCTION AND COMPARISON WITH DIESEL EXHAUST GAS RECIRCULATION To prevent the malicious knock phenomenon. Scheme of the intake burned gas fraction dynamics. In the seemingly similar context of automotive Diesel

214

Catalytic converter applications for two stroke, spark-ignited marine engines  

SciTech Connect (OSTI)

When catalytic converters are used for cleansing of exhaust gas from two-stroke marine engines, new issues must be brought up in combination with prior technology. Therefore, a study was made of V6, 2600cc engine having a large volume of hydrocarbon emissions with respect to three issues: (1) To what degree seawater effects catalytic converter performance and possible countermeasures; (2) Effects attained on cleansing level and catalyst temperature; (3) Finding abatement levels for catalyst deterioration and exhaust emission output in the marine mode. It was found that physical adsorption was a significant factor in catalytic degradation resulting from direct contact with seawater. The cleansing levels obtained when a marine engine is equipped with a catalyst converter were found by clarifying the extent of effects of catalyst volume, performance and temperature. The reduction obtained in exhaust emission allowing for a deterioration factor, is shown in a catalytic converter heated to the maximum temperature of 960 C.

Fujimoto, Hiroaki; Isogawa, Atsushi; Matsumoto, Naoto

1995-12-31T23:59:59.000Z

215

Impact of N2 dilution on combustion and emissions in a spark ignition CNG engine  

Science Journals Connector (OSTI)

Abstract In order to reduce \\{NOx\\} (nitrogen oxides) emissions, N2 (nitrogen) was introduced as dilution gas to dilute mixture with a specially-designed injection device. The impacts of varying N2 DR (dilution ratio) on the combustion and the exhaust emissions were investigated, including engine heat release rate, indicator diagram, NOx, CO (carbon monoxide), THC (total hydrocarbon) emissions and so on. For this study, a modified 6.6 L CNG (compressed natural gas) engine was tested and N2 was injected into the end of intake manifold by a specially-designed device. The results showed that N2 dilution has a significant influence on the combustion and the exhaust emissions. With the rise of N2 DR, the maximum of pressure in cylinder and the maximum of heat release rate exhibited decrease trends, the centre of heat release curve showed a moving backward tendency. Higher N2 DR exhibited lower \\{NOx\\} (17–81%) emissions, but higher emissions of THC (3–78%) and CO (1–28%). The change of BSFC (brake specific fuel consumption) can be ignored with N2 DR no more than 167%. Satisfactory results can be obtained, with lower \\{NOx\\} (31%) emissions, lower BSFC (0.5%), and relatively higher THC (6%) and CO (1%) emissions, when N2 DR is 67%.

Zhongshu Wang; Hongbin Zuo; Zhongchang Liu; Weifeng Li; Huili Dou

2014-01-01T23:59:59.000Z

216

Short term measures for the reduction of fuel consumption of spark ignition engines  

Science Journals Connector (OSTI)

With regard to the ACEA commitment the question arises as to how the CO2...target values can be met. Measures such as a further increase of the Diesel market share are reaching the limits of what is economically ...

Wolfgang Salber; Jürgen Dohmen; Oliver Lang; Rolf Weinowski

2006-10-01T23:59:59.000Z

217

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

Broader source: Energy.gov [DOE]

Poster presented at the 16th Directions in Engine-Efficiency and Emissions Research (DEER) Conference in Detroit, MI, September 27-30, 2010.

218

Combustion instabilities and nanoparticles emission fluctuations in GDI spark ignition engine  

Science Journals Connector (OSTI)

The main challenge facing the concept of gasoline direct injection is the unfavourable physical conditions at which the premixed charge is prepared and burned. These conditions include the short time available...

A. E. Hassaneen; S. Samuel; I. Whelan

2011-12-01T23:59:59.000Z

219

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

Broader source: Energy.gov [DOE]

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

220

Numerical Simulation of Combustion Processes in Homogeneous and Stratified Charge Spark Ignition Engines  

Science Journals Connector (OSTI)

A three-dimensional simulation technique for stratified combustion process in direct injection gasoline engines is developed....

Hiroshi Miyagawa; Yoshihiro Nomura; Makoto Koike

2001-01-01T23:59:59.000Z

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

Performance of a spark ignition engine fueled with methanol or methanol-gasoline blends  

SciTech Connect (OSTI)

Engine torque and specific energy consumption of an automotive engine were studied under steady state condition using gasoline, methanol gasoline blends and straight methanol as fuel. At first the engine was run without any modification. Next the diameters of metering orifices in carburetor were modified to give the same excess air factor regardless of fuel type under each fixed engine operating condition. Finally the engine was run with 15% mixture methanol in gasoline by volume using the carburetor modified to have approximately 10% larger fuel flow area than the production carburetor. From the results of this study the effects of using methanol on engine torque and specific energy consumption can be explained on the basis of change in stoichiometry caused by the use of methanol.

You, B.C.

1983-11-01T23:59:59.000Z

222

Predicting Ignition Delay for Gas Turbine Fuel Flexibility  

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

Ignition Delay for Ignition Delay for Gas Turbine Fuel Flexibility 15 ÎĽm * 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 Ď„ [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

223

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":""}]}

224

The National Ignition Facility and the Ignition Campaign  

E-Print Network [OSTI]

February 14-18, 2013 Debra A. Callahan Group Leader for ICF/IFE Target design Lawrence Livermore National(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

225

Conceptual Design - Polar Drive Ignition Campaign  

SciTech Connect (OSTI)

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

226

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

227

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

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

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

228

National Ignition Campaign Hohlraum Energetics  

SciTech Connect (OSTI)

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

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

2009-11-16T23:59:59.000Z

229

The National Ignition Campaign: status and progress  

Science Journals Connector (OSTI)

The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) has been operational since March 2009 and a variety of experiments have been completed and many more are planned in support of NIF's mission areas: national security, fundamental science, and fusion energy. NIF capabilities and infrastructure are in place to support all of its missions with nearly 60 x-ray, optical and nuclear diagnostic systems and the ability to shoot cryogenic targets and DT layered capsules. The NIF has also been qualified for the use of tritium and other special materials as well as to perform high-yield experiments and classified experiments. Implosions with record indirect-drive neutron yield of 7.5 ? 1014 neutrons have been achieved. NIF, a Nd?:?Glass laser facility, is routinely operating at 1.6 MJ of ultraviolet (3?) light on target with very high reliability. It recently reached its design goal of 1.8 MJ and 500 TW of 3? light on target, and has performed target experiments with 1.9 MJ at peak powers of 410 TW. The National Ignition Campaign (NIC), an international effort with the goal of demonstrating thermonuclear burn in the laboratory, is making steady progress towards achieving ignition. Other experiments have been completed in support of high-energy science, materials equation of state, and materials strength. In all cases, records of extreme temperatures and pressures, highest neutron yield and highest energy densities have been achieved. This paper describes the unprecedented experimental capabilities of the NIF and the results achieved so far on the path towards ignition.

E.I. Moses; the NIC Collaborators

2013-01-01T23:59:59.000Z

230

Ignition characteristics of laser-ionized fuel injected into a hypersonic crossflow  

Science Journals Connector (OSTI)

Abstract This paper presents an experimental investigation on the ignition characteristics of laser-ionized fuel injected into a hypersonic air-crossflow. A Q-switched laser causes breakdown in the sonic H2 injector stream before interaction with the air-crossflow traveling at 2 km/s with a total specific enthalpy of 2.5 MJ/kg. The flowfield is visualized using schlieren imaging and planar laser-induced fluorescence (PLIF) on the NO molecule. The temporal evolution of the ignition process is visualized using PLIF on the OH molecule. We compare the ignition effectiveness, in terms of the OH PLIF signal, between a series of test cases with different injector pressures and laser energies. These results are also compared to a previous study, where the laser-spark was generated in the jet interaction region, outside the fuel injector. The influence of using H2 fuel diluted with Ar, which serves as a plasma buffer gas, to extend plasma lifetimes is also investigated. The ignition technique is found to be effective in terms of post-plasma hydroxyl production, with a significant increase in performance observed when Ar is used as a plasma buffer gas.

Stefan Brieschenk; Sean O’Byrne; Harald Kleine

2014-01-01T23:59:59.000Z

231

Enhanced Model for Fast Ignition  

SciTech Connect (OSTI)

Laser Fusion is a prime candidate for alternate energy production, capable of serving a major portion of the nationâ??s energy needs, once fusion fuel can be readily ignited. Fast Ignition may well speed achievement of this goal, by reducing net demands on laser pulse energy and timing precision. However, Fast Ignition has presented a major challenge to modeling. This project has enhanced the computer code ePLAS for the simulation of the many specialized phenomena, which arise with Fast Ignition. The improved code has helped researchers to understand better the consequences of laser absorption, energy transport, and laser target hydrodynamics. ePLAS uses efficient implicit methods to acquire solutions for the electromagnetic fields that govern the accelerations of electrons and ions in targets. In many cases, the code implements fluid modeling for these components. These combined features, â??implicitness and fluid modeling,â?ť can greatly facilitate calculations, permitting the rapid scoping and evaluation of experiments. ePLAS can be used on PCs, Macs and Linux machines, providing researchers and students with rapid results. This project has improved the treatment of electromagnetics, hydrodynamics, and atomic physics in the code. It has simplified output graphics, and provided new input that avoids the need for source code access by users. The improved code can now aid university, business and national laboratory users in pursuit of an early path to success with Fast Ignition.

Dr. Rodney J. Mason

2010-10-12T23:59:59.000Z

232

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

Broader source: Energy.gov [DOE]

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

233

Lean burn limit and time to light characteristics of laser ignition in gas turbines  

Science Journals Connector (OSTI)

Abstract This work details a study of laser ignition in a low pressure combustion test rig, representative of an industrial gas turbine (SGT-400, Siemens Industrial Turbomachinery Ltd.) and for the first time investigates the effect of air mass flow rate on combustion characteristics at air/fuel ratios at the lean burn limit. Both the lean burn limit and time taken to light are essential in determining the suitability of a specified air/fuel ratio, especially in multi-chamber ignition applications. Through extension of the lean burn limit and reduction of the time taken to light, the operating window for ignition with regards to the air/fuel ratio can be increased, leading to greater reliability and repeatability of ignition. Ignition of a natural gas and air mixture at atmospheric pressure was conducted using both a standard high energy igniter and a laser ignition system utilizing a Q-switched Nd:YAG laser source operating at 1064 nm wavelength. A detailed comparison of the lean burn limit and time taken to light for standard ignition and laser ignition is presented.

J. Griffiths; M. Riley; A. Kirk; A. Borman; J. Lawrence; C. Dowding

2014-01-01T23:59:59.000Z

234

Thermonuclear Ignition of Dark Galaxies  

E-Print Network [OSTI]

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

J. Marvin Herndon

2006-04-13T23:59:59.000Z

235

The National Ignition Facility and the Path to Fusion Energy  

SciTech Connect (OSTI)

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

236

June 11, 1999: National Ignition Facility  

Broader source: Energy.gov [DOE]

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

237

Heating National Ignition Facility, Realistic Financial Planning...  

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

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

238

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.

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

1998-01-01T23:59:59.000Z

239

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

240

Symmetry tuning for ignition capsules via the symcap technique  

SciTech Connect (OSTI)

Symmetry of an implosion is crucial to get ignition successfully. Several methods of control and measurement of symmetry have been applied on many laser systems with mm size hohlraums and ns pulses. On the National Ignition Facility [Moses et al., Phys. Plasmas 16, 041006 (2009)] we have large hohlraums of cm scale, long drive pulses of 10 s of ns, and a large number of beams with the option to tune their wavelengths. Here we discuss how we used the x-ray self-emission from imploding surrogates to ignition capsules (symcaps) to measure the symmetry of the implosion. We show that symcaps are good surrogates for low order symmetry, though having lower sensitivity to distortions than ignition capsules. We demonstrate the ability to transfer energy between laser beams in a gas-filled hohlraum using wavelength tuning, successfully tuning the lowest order symmetry of the symcaps in different size hohlraums at different laser energies within the specification established by calculations for successful ignition.

Kyrala, G. A.; Kline, J. L. [Los Alamos National Laboratory, P.O. Box 1663, MS E-526, Los Alamos, New Mexico 87544 (United States); Dixit, S.; Glenzer, S.; Kalantar, D.; Bradley, D.; Izumi, N.; Meezan, N.; Landen, O.; Callahan, D.; Weber, S. V.; Holder, J. P.; Glenn, S.; Edwards, M. J.; Koch, J.; Suter, L. J.; Haan, S. W.; Town, R. P. J.; Michel, P.; Jones, O. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)

2011-05-15T23:59:59.000Z

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.


241

Ignition feedback regenerative free electron laser (FEL) amplifier  

DOE Patents [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

242

Fusion Ignition Research Experiment Princeton Plasma Physics Laboratory  

E-Print Network [OSTI]

Fusion Ignition Research Experiment Dale Meade Princeton Plasma Physics Laboratory Abstract Understanding the properties of high gain (alpha­dominated) fusion plasmas in an advanced toroidal configuration­dominated plasmas in advanced toroidal systems. Technical Challenges for Major Next Steps in Magnetic Fusion Energy

243

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

SciTech Connect (OSTI)

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

244

NEVADA SPARKS RESIDENTS TO IMPROVE ENERGY FITNESS | Department...  

Energy Savers [EERE]

and Sparks, Nevada. The program's goals included creating the foundation for a self-sustaining program that would help the state meet its goal to upgrade 5% of all...

245

Diagnostics for Fast Ignition Science  

SciTech Connect (OSTI)

The concept for Electron Fast Ignition Inertial Confinement Fusion demands sufficient laser energy be transferred from the ignitor pulse to the assembled fuel core via {approx}MeV electrons. We have assembled a suite of diagnostics to characterize such transfer. Recent experiments have simultaneously fielded absolutely calibrated extreme ultraviolet multilayer imagers at 68 and 256eV; spherically bent crystal imagers at 4 and 8keV; multi-keV crystal spectrometers; MeV x-ray bremmstrahlung and electron and proton spectrometers (along the same line of sight); nuclear activation samples and a picosecond optical probe based interferometer. These diagnostics allow careful measurement of energy transport and deposition during and following laser-plasma interactions at extremely high intensities in both planar and conical targets. Augmented with accurate on-shot laser focal spot and pre-pulse characterization, these measurements are yielding new insight into energy coupling and are providing critical data for validating numerical PIC and hybrid PIC simulation codes in an area that is crucial for many applications, particularly fast ignition. Novel aspects of these diagnostics and how they are combined to extract quantitative data on ultra high intensity laser plasma interactions are discussed, together with implications for full-scale fast ignition experiments.

MacPhee, A; Akli, K; Beg, F; Chen, C; Chen, H; Clarke, R; Hey, D; Freeman, R; Kemp, A; Key, M; King, J; LePape, S; Link, A; Ma, T; Nakamura, N; Offermann, D; Ovchinnikov, V; Patel, P; Phillips, T; Stephens, R; Town, R; Wei, M; VanWoerkom, L; Mackinnon, A

2008-05-06T23:59:59.000Z

246

Fast ignition of inertial confinement fusion targets  

SciTech Connect (OSTI)

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

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

2013-01-15T23:59:59.000Z

247

First Hot Electron Measurements in Near-ignition Scale Hohlraums on the National Ignition Facility  

SciTech Connect (OSTI)

On the National Ignition Facility (NIF), the hot electrons generated in laser heated hohlraums are inferred from the >20 keV bremsstrahlung emission measured with the FFLEX broadband spectrometer. New high energy (>200 keV) time resolved channels were added to meet requirements for ignition and to infer the generated >170 keV hot electrons that can cause ignition capsule preheat. First hot electron measurements in near ignition scaled hohlraums heated by 96-192 NIF laser beams are presented.

Dewald, E L; Suter, L J; Thomas, C; Hunter, S; Meeker, D; Meezan, N; Glenzer, S H; Bond, E; Kauffman, R L; Kilkenny, J; Landen, O

2009-10-08T23:59:59.000Z

248

The National Ignition Facility National Ignition Campaign Short Pulse Lasers High-Average-Power Laser  

E-Print Network [OSTI]

#12;The National Ignition Facility National Ignition Campaign Short Pulse Lasers High hole shields SSD, Polarization smoothing Improvements in ignition point designs have reduced laser Campaign NIF-0905-11310 09EIM/dj 1997 1.7 MJ ignition point design 0.5 0.4 0.3 0.2 0.1 0 0 0.5 1 1.5 Laser

249

Stoichiometric Compression Ignition (SCI) Engine Concept | Department...  

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

More Documents & Publications An Experimental Investigation of the Origin of Increased NOx Emissions When Fueling a Heavy-Duty Compression-Ignition Engine with...

250

Physics Guidelines for the Compact Ignition Tokamak  

Science Journals Connector (OSTI)

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

J. Sheffield; R. A. Dory; W. A. Houlberg; N. A. Uckan; M. Bell; P. Colestock; J. Hosea; S. Kaye; M. Petravic; D. Post; S. D. Scott; K. M. Young; K. H. Burrell; N. Ohyabu; R. Stambaugh; M. Greenwald; P. Liewer; D. Ross; C. Singer; H. Weitzner

251

Achieving laser ignition using zero index metamaterials  

Science Journals Connector (OSTI)

The possibility of laser ignition using zero index metamaterials (ZIM) is investigated theoretically. Using this method, multiple laser beams can be focused automatically regardless of...

Zhai, Tianrui; Shi, Jinwei; Chen, Shujing; Liu, Dahe; Zhang, Xinping

2011-01-01T23:59:59.000Z

252

Laser Fusion: The Uncertain Road to Ignition  

Science Journals Connector (OSTI)

In early 2014, the U.S. National Ignition Facility announced that it had achieved a fusion reaction that produced net positive energy. Fusion scientists have applauded that...

Rose, Melinda

2014-01-01T23:59:59.000Z

253

National Ignition Facility | National Nuclear Security Administration  

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

other ICF high energy density facilities leading to demonstrate fusion ignition and thermonuclear burn in the laboratory. The NIF is also being used to support basic science and...

254

Fast Ignition Program in Japan "Progress of Fast Ignition Project; FIREX"  

E-Print Network [OSTI]

1 Fast Ignition Program in Japan "Progress of Fast Ignition Project; FIREX" Fast Ignition.4 Fusion , Laser Astrophysics, EUV, and so on are main projects Laser Spectroscopy NIFS, Okayama Univ., High Pressure EOS AIST Tokyo Inst. Tech Laser Acceleration, Terahertz Coherent X-Ray JAEA KPRI Fusion

255

Assessment of Potential for Ion Driven Fast Ignition  

E-Print Network [OSTI]

mm radius ion beams Fast Ignition (laser or fast ion pulse)deg half cone angle Fast Ignition (laser or fast ion pulse)ion beam pulses for fast ignition, laser generated ion beams

2005-01-01T23:59:59.000Z

256

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

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

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

257

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

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

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

258

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":""}]}

259

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

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

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

260

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

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

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

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.


262

Target Diagnostics Supports NIF's Path to Ignition  

SciTech Connect (OSTI)

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

263

Turbulent decay of after-spark channels M. N. Shneider  

E-Print Network [OSTI]

of the entire evolution of a spark discharge and the subsequent cooling of the postdischarge channel are discussed. The stabilizing effect of the continuous residual electric current on the plasma cooling The pulsed arcs have been traditionally used in high- current and high-voltage commutators1

Miles, Richard

264

Inertial Confinement Fusion: steady progressInertial Confinement Fusion: steady progress towards ignition and high gaintowards ignition and high gain  

E-Print Network [OSTI]

, Vilamoura, Portugal. #12;Main route to ignition: indirect laser drive with central hot-spot ignition and ignition implosion DT capsule hohlraum case ~ 30 m of Au (or Pb)µ laser beams 5.5 mm 9.5 mm ablator DT ice constantly accumulated on currently operating non- ignition-scale lasers at Rochester, LANL, ILE, UK

265

Fast Ignition: Nuclear Fusion with UltraFast Ignition: Nuclear Fusion with Ultra--intenseintense LASERsLASERs  

E-Print Network [OSTI]

pellet composed of deuterium and tritium. In the fast ignition regime a secondy p g g p p g g laser, nearly limitless, fuel source. Fusion via Fast Ignition MethodUltra-Intense Laser Research atFusion via Direct Drive Method U Strathclyde IgnitionCompression IgnitionCompression · Very intense lasers (shown

Strathclyde, University of

266

Hot electron measurements in ignition relevant Hohlraums on the National Ignition Facility  

SciTech Connect (OSTI)

On the National Ignition Facility (NIF), hot electrons generated in laser heated Hohlraums are inferred from the >20 keV bremsstrahlung emission measured with the time integrated FFLEX broadband spectrometer. New high energy (>200 keV) time resolved channels were added to infer the generated >170 keV hot electrons that can cause ignition capsule preheat. First hot electron measurements in near ignition scaled Hohlraums heated by 96-192 NIF laser beams are presented.

Dewald, E. L.; Thomas, C.; Hunter, S.; Divol, L.; Meezan, N.; Glenzer, S. H.; Suter, L. J.; Bond, E.; Celeste, J.; Bradley, D.; Bell, P.; Kauffman, R. L.; Landen, O. L. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States); Kline, J. L. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Kilkenny, J. [General Atomics, P.O. Box 85608, San Diego, California 92186 (United States)

2010-10-15T23:59:59.000Z

267

Inertial-confinement fusion with fast ignition  

Science Journals Connector (OSTI)

...achieve ignition and thermonuclear burn. For a fusion power plant, gains...the ratio of the thermonuclear energy to the initial...released by the thermonuclear burn in unit mass...compressed spherical fusion fuel. Higher gain...

1999-01-01T23:59:59.000Z

268

History of the approach to ignition  

Science Journals Connector (OSTI)

...International Thermonuclear Experimental Reactor...recommended. plasma|fusion|tokamak|ignition...density plasma to thermonuclear temperatures...in the quest for fusion power. Such an...temperatures of thermonuclear interest, this...for an acceptable fusion reactor. By a...

1999-01-01T23:59:59.000Z

269

Ignition with Laser Break-Down  

Science Journals Connector (OSTI)

It is considered that ignition with laser break-down is one of the applications of solid-state lasers. This paper shows basic experimental results indicating the advantages of laser...

Furutani, Hirohide; Saito, Takeshi

270

Focus issue introduction: Laser Ignition Conference  

Science Journals Connector (OSTI)

The purpose of this feature issue is to share information on laser ignition and related sciences and technologies. This feature offers five papers in the field that cover aspects of...

Taira, Takunori; Furutani, Hirohide; Guo, Chunlei; Wintner, Ernst; Akamatsu, Fumiteru; Lucht, Robert; Washio, Kunihiko

2014-01-01T23:59:59.000Z

271

Confinement scaling and ignition in tokamaks  

SciTech Connect (OSTI)

A drift wave turbulence model is used to compute the scaling and magnitude of central electron temperature and confinement time of tokamak plasmas. The results are in accord with experiment. Application to ignition experiments shows that high density (1 to 2) . 10/sup 15/ cm/sup -3/, high field, B/sub T/ > 10 T, but low temperature T approx. 6 keV constitute the optimum path to ignition.

Perkins, F.W.; Sun, Y.C.

1985-10-01T23:59:59.000Z

272

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

273

Mathematical analysis of spark ignition engine operation via the combination of the first and second laws of thermodynamics  

Science Journals Connector (OSTI)

...exh exergy transfer with exhaust gases, J A f area of flame front, m2...diameter, m E energy, J f mass residual gas fraction, dimensionless h specific...engine. Trans. ASME J. Eng. Gas Turbines Power. 110, 462-469. Bayraktar...

2008-01-01T23:59:59.000Z

274

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

E-Print Network [OSTI]

Products Product Mole Fractions CO COP H OH H2 N H 0 NO N2 0 02 . 8788D 00 . 7120D 01 . 2990D-01 . 2122D 00 . 1970D 00 . 8680D 01 . 1601D-05 . 1665D 00 . II705D 02 . 21IIOD-01 ~ 3990D oo . 8809D 00 . 7119D ol 2991D-ol ~ 2037D 00... . 1976D 00 . 8685D ol 1593D-o5 . 1654D 00 ~ 4704D 02 ~ 2123D-01 . 3942D 00 Table 2 Comparison of Adiabatic Flame Temperatures and Equilibrium Compositions for Combustion of C8H18 with Air at a Constant Volume, Stoichiometric Fuel/Air ratio...

Brown, William Charles

2012-06-07T23:59:59.000Z

275

Combustion Characteristics and Heat Release Analysis of a Spark-Ignited Engine Fueled with Natural Gas?Hydrogen Blends  

Science Journals Connector (OSTI)

It can be seen that the laminar-burning velocity of hydrogen is 5 times that of natural gas and that the quenching distance of hydrogen is one-third that of natural gas, while the latter is beneficial to reduce the unburned hydrocarbons near the wall and from the top-land crevice. ... The signal of cylinder pressure was acquired for every 0.5 deg CA, the acquisition process covered 254 completed cycles, and the averaged value of these 254 cycles was outputted as the pressure data for calculation of the combustion parameters. ... Two factors are considered to influence the cylinder pressure:? one is the increase in flame propagation speed or combustion speed with the increase of the hydrogen fraction in the blends, and this will cause a rapid rising in the cylinder pressure and bring a higher value of the peak cylinder pressure; another is the decrease in the heating value of the fuel blends with the increase of the hydrogen fraction in natural gas?hydrogen blends, and this will decrease the volumetric heat release rate and the cylinder pressure rising, leading to the lower value of the peak cylinder pressure. ...

Zuohua Huang; Bing Liu; Ke Zeng; Yinyu Huang; Deming Jiang; Xibin Wang; Haiyan Miao

2007-08-15T23:59:59.000Z

276

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

277

Modeling of homogeneous charge compression ignition (HCCI) of methane  

SciTech Connect (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

278

GREET Development and Applications for Life-Cycle Analysis of...  

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

Gas Animal Waste Waste water treatment 6 Coke Oven Gas Petroleum Coke Nuclear Energy Hydrogen GREET Examines More Than 85 VehicleFuel Systems Conventional Spark-Ignition...

279

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

280

High Radon Levels in Homes Spark Moves To Combat Pollutant  

Science Journals Connector (OSTI)

High Radon Levels in Homes Spark Moves To Combat Pollutant ... Federal, state agencies have initiated programs to monitor levels of this inert radioactive gas in homes in certain areas and work out control strategy ... Health care officials have been concerned about radon for more than 20 years, but public attention reached a new high recently with the discovery of high levels of radon inside homes in the New Jersey- Pennsylvania-New York area. ...

DAVID J. HANSON

1985-11-18T23:59:59.000Z

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

The role of the National Ignition Facility in energy production from inertial fusion  

Science Journals Connector (OSTI)

...in IFE attractive. inertial fusion energy|laser fusion|ignition (lasers)|thermonuclear gain|National Ignition Facility...inertial fusion energy; laser fusion; ignition (lasers); thermonuclear gain; National Ignition Facility...

1999-01-01T23:59:59.000Z

282

Analytical model for fast-shock ignition  

SciTech Connect (OSTI)

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

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

2014-07-15T23:59:59.000Z

283

Thermonuclear supernova simulations with stochastic ignition  

E-Print Network [OSTI]

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

W. Schmidt; J. C. Niemeyer

2005-10-14T23:59:59.000Z

284

Single-cylinder engine as a tool for developing new combustion processes  

Science Journals Connector (OSTI)

In the race to perfect the combustion process of tomorrow engine developers are focusing on ... ignition and diesel systems with stratified spark-ignition combustion processes along with a variety of technologies...

Frank Menzel; Thomas Seidel; Wulf Schmidt; Julius Pape; Lutz Stiegler

2006-03-01T23:59:59.000Z

285

Numerical simulation of laser ignition of a liquid fuel film  

Science Journals Connector (OSTI)

Numerical simulations were used to examine a set of interrelated physicochemical processes involved in the ignition of a liquid fuel film by a low-power laser beam. The delay time of ignition of a liquid fuel fil...

G. V. Kuznetsov; P. A. Strizhak

2010-08-01T23:59:59.000Z

286

Laser ignition in internal-combustion engines: Sparkless initiation  

Science Journals Connector (OSTI)

Laser ignition has been implemented in a single-cylinder ... pressure versus crank angle) were obtained for laser ignition with nano- and microsecond pulses of an Nd:YAG laser. The maximum power of microsecond pu...

A. A. Andronov; V. A. Gurin; A. V. Marugin; A. P. Savikin…

2014-08-01T23:59:59.000Z

287

National Ignition Facility & Photon Science NIF Fun Facts  

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

7 National Ignition Facility & Photon Science NIF Fun Facts niF Fun Facts The National Ignition Facility (NIF), became operational in march 2009. Planning began in the early 1990s,...

288

The velocity campaign for ignition on NIF  

SciTech Connect (OSTI)

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

289

Ignition of deuterium-tritium fuel targets  

DOE Patents [OSTI]

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

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

1991-08-27T23:59:59.000Z

290

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

Energy Savers [EERE]

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

291

Shock Ignition: A New Approach to High Gain Inertial Confinement Fusion on the National Ignition Facility  

Science Journals Connector (OSTI)

Shock ignition, an alternative concept for igniting thermonuclear fuel, is explored as a new approach to high gain, inertial confinement fusion targets for the National Ignition Facility (NIF). Results indicate thermonuclear yields of ?120–250??MJ may be possible with laser drive energies of 1–1.6 MJ, while gains of ?50 may still be achievable at only ?0.2??MJ drive energy. The scaling of NIF energy gain with laser energy is found to be G?126E??(MJ)0.510. This offers the potential for high-gain targets that may lead to smaller, more economic fusion power reactors and a cheaper fusion energy development path.

L. J. Perkins; R. Betti; K. N. LaFortune; W. H. Williams

2009-07-23T23:59:59.000Z

292

Scaling laws for ignition at the National Ignition Facility from first principles  

Science Journals Connector (OSTI)

We have developed an analytical physics model from fundamental physics principles and used the reduced one-dimensional model to derive a thermonuclear ignition criterion and implosion energy scaling laws applicable to inertial confinement fusion capsules. The scaling laws relate the fuel pressure and the minimum implosion energy required for ignition to the peak implosion velocity and the equation of state of the pusher and the hot fuel. When a specific low-entropy adiabat path is used for the cold fuel, our scaling laws recover the ignition threshold factor dependence on the implosion velocity, but when a high-entropy adiabat path is chosen, the model agrees with recent measurements.

Baolian Cheng; Thomas J. T. Kwan; Yi-Ming Wang; Steven H. Batha

2013-10-07T23:59:59.000Z

293

Experimental basis for laser-plasma interactions in ignition hohlraums at the National Ignition Facility  

SciTech Connect (OSTI)

A series of laser plasma interaction experiments at OMEGA (LLE, Rochester) using gas-filled hohlraums shed light on the behavior of stimulated Raman scattering and stimulated Brillouin scattering at various plasma conditions encountered in indirect drive ignition designs. We present detailed experimental results that quantify the density, temperature, and intensity thresholds for both of these instabilities. In addition to controlling plasma parameters, the National Ignition Campaign relies on optical beam smoothing techniques to mitigate backscatter. We show that polarization smoothing is effective at controlling backscatter. These results provide an experimental basis for forthcoming experiments on National Ignition Facility.

Froula, D H; Divol, L; London, R A; Berger, R L; Doeppner, T; Meezan, N B; Ralph, J; Ross, J S; Suter, L J; Glenzer, S H

2009-11-12T23:59:59.000Z

294

Laser-Plasma Coupling with Ignition-Scale Targets: New Regimes and Frontiers on the National Ignition Facility  

Science Journals Connector (OSTI)

It is very exciting that the National Ignition Facility (NIF) is now operational and being used to irradiate ignition-scale hohlraums. As discussed in the last ... Summer School in Physics on the topic of laser-p...

William L. Kruer

2013-01-01T23:59:59.000Z

295

Homogeneous Charge Compression Ignition Free Piston Linear Alternator  

SciTech Connect (OSTI)

An experimental and theoretical investigation of a homogeneous charge compression ignition (HCCI) free piston powered linear alternator has been conducted to determine if improvements can be made in the thermal and conversion efficiencies of modern electrical generator systems. Performance of a free piston engine was investigated using a rapid compression expansion machine and a full cycle thermodynamic model. Linear alternator performance was investigated with a computer model. In addition linear alternator testing and permanent magnet characterization hardware were developed. The development of the two-stroke cycle scavenging process has begun.

Janson Wu; Nicholas Paradiso; Peter Van Blarigan; Scott Goldsborough

1998-11-01T23:59:59.000Z

296

Thermite powder ignition by localized microwaves Yehuda Meir, Eli Jerby  

E-Print Network [OSTI]

, there is a considerable motivation to develop practical means to ignite pure thermites. Laser beams were found effectiveThermite powder ignition by localized microwaves Yehuda Meir, Eli Jerby Faculty of Engineering 2012 Keywords: Thermite Microwave heating Hotspots Thermal runaway Ignition a b s t r a c t This paper

Jerby, Eli

297

Planning for the National Ignition Campaign on NIF Presentation to  

E-Print Network [OSTI]

yields>1 MJ (an ignition margin >1) with the expected precision of target experiments, laser performance by melting with the first shock ·We predict an ignition margin >1 at the point design laser energy #12;A CH that roll up to set the ignition conditions ~150 lower parameters 1D quantities, e.g: Peak Laser Power Foot

298

Thermite powder ignition by localized microwaves Yehuda Meir, Eli Jerby  

E-Print Network [OSTI]

, there is a considerable motivation to develop practical means to ignite pure thermites. Laser beams were found effectiveThermite powder ignition by localized microwaves Yehuda Meir, Eli Jerby Faculty of Engineering Keywords: Thermite Microwave heating Hotspots Thermal runaway Ignition a b s t r a c t This paper presents

Jerby, Eli

299

Inertial Confinement Fusion Ignition and High Yield Campaign  

E-Print Network [OSTI]

to redirect High Average Power Lasers to be synergistic with NIF ignition and other defense missions #12 · Predicted gains (fusion energy produced/laser energy input) have increased · Direct drive ignition shows) Project has begun · Will add two high-energy petawatt lasers for OMEGA for advanced backlighting and fast-ignition

300

Status of Experiments on National Ignition Facility Presented to  

E-Print Network [OSTI]

into the hohlraum temperature range for ignition experiments at 280-300 eV · The laser, diagnostic, targetStatus of Experiments on National Ignition Facility Presented to 31st Annual Meeting and Symposium Associates 4NIF­1110-20542.ppt #12;National Ignition Campaign goals Moses - 31st Annual Meeting and Symposium

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

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

SciTech Connect (OSTI)

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

302

FUSION IGNITION RESEARCH EXPERIMENT SYSTEM INTEGRATION *  

E-Print Network [OSTI]

in an arrangement that allows remote maintenance of in-vessel components and hands-on maintenance by integrating the two components into a single module. This was done to increase the baffle heat. An in­vessel remote maintenance module is also shown attached to one port. Figure 2 highlights

303

National Ignition Facility Title II Design Plan  

SciTech Connect (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

304

Impacts assessment for the National Ignition Facility  

SciTech Connect (OSTI)

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

Bay Area Economics

1996-12-01T23:59:59.000Z

305

Weapons Activities/ Inertial Confinement Fusion Ignition  

E-Print Network [OSTI]

a safe, secure, and reliable nuclear weapons stockpile without underground testing. Science-based weapons and certify the stockpile without nuclear testing. The National Ignition Facility (NIF) extends HEDP under extreme conditions that approach the high energy density (HED) environments found in a nuclear

306

Weapons Activities/ Inertial Confinement Fusion Ignition  

E-Print Network [OSTI]

, and reliability of the Nation's nuclear weapons without nuclear testing. The program provides this capability models that are used to assess and certify the stockpile without nuclear testing. The National Ignition that approach the high-energy density (HED) environments found in a nuclear explosion. Virtually all

307

Spark Plasma Sintering of Fuel Cermets for Nuclear Reactor Applications  

SciTech Connect (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

308

Spark Plasma Sintering of W-UO2 Cermets  

SciTech Connect (OSTI)

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

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

2013-02-01T23:59:59.000Z

309

Low-pressure spark gap triggered by an ion diode  

DOE Patents [OSTI]

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

Prono, D.S.

1982-08-31T23:59:59.000Z

310

Groundbreaking at National Ignition Facility | National Nuclear Security  

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

311

X-ray driven implosions at ignition relevant velocities on the National Ignition Facility  

SciTech Connect (OSTI)

Backlit convergent ablator experiments on the National Ignition Facility [E. I. Moses et al., Phys. Plasmas 16, 041006 (2009)] are indirect drive implosions that study the inflight dynamics of an imploding capsule. Side-on, backlit radiography provides data used by the National Ignition Campaign to measure time-dependent properties of the capsule ablator including its center of mass radius, velocity, and unablated mass. Previously, Callahan [D. A. Callahan et al., Phys. Plasmas 19, 056305 (2012)] and Hicks [D. H. Hicks et al., Phys. Plasmas 19, 122702 (2012)] reported backlit convergent ablator experiments demonstrating velocities approaching those required for ignition. This paper focuses on implosion performance data in the “rocket curve” plane, velocity vs. ablator mass. These rocket curve data, along with supporting numerical simulations, show that the nominal 195 ?m-thick ignition capsule would reach the ignition velocity goal V = 370 km/s with low ablator mass remaining–below the goal of M = 0.25 mg. This finding led to experiments with thicker capsule ablators. A recent symmetry capsule experiment with a 20 ?m thicker capsule driven by 520 TW, 1.86 MJ laser pulse (along with a companion backlit convergent ablator experiment) appears to have demonstrated V?350 km/s with ablator mass remaining above the ignition goal.

Meezan, N. B.; MacKinnon, A. J.; Hicks, D. G.; Dewald, E. L.; Tommasini, R.; Le Pape, S.; Döppner, T.; Ma, T.; Farley, D. R.; Kalantar, D. H.; Di Nicola, P.; Callahan, D. A.; Robey, H. F.; Thomas, C. A.; Prisbrey, S. T.; Jones, O. S.; Milovich, J. L.; Clark, D. S.; Eder, D. C.; Schneider, M. B. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808 (United States)] [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808 (United States); and others

2013-05-15T23:59:59.000Z

312

Point design targets, specifications, and requirements for the 2010 ignition campaign on the National Ignition Facility  

SciTech Connect (OSTI)

Point design targets have been specified for the initial ignition campaign on the National Ignition Facility [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 443, 2841 (2004)]. The targets contain D-T fusion fuel in an ablator of either CH with Ge doping, or Be with Cu. These shells are imploded in a U or Au hohlraum with a peak radiation temperature set between 270 and 300 eV. Considerations determining the point design include laser-plasma interactions, hydrodynamic instabilities, laser operations, and target fabrication. Simulations were used to evaluate choices, and to define requirements and specifications. Simulation techniques and their experimental validation are summarized. Simulations were used to estimate the sensitivity of target performance to uncertainties and variations in experimental conditions. A formalism is described that evaluates margin for ignition, summarized in a parameter the Ignition Threshold Factor (ITF). Uncertainty and shot-to-shot variability in ITF are evaluated, and sensitivity of the margin to characteristics of the experiment. The formalism is used to estimate probability of ignition. The ignition experiment will be preceded with an experimental campaign that determines features of the design that cannot be defined with simulations alone. The requirements for this campaign are summarized. Requirements are summarized for the laser and target fabrication.

Haan, S. W.; Lindl, J. D.; Callahan, D. A.; Clark, D. S.; Salmonson, J. D.; Hammel, B. A.; Atherton, L. J.; Cook, R. C.; Edwards, M. J.; Glenzer, S.; Hamza, A. V.; Hatchett, S. P.; Hinkel, D. E.; Ho, D. D.; Jones, O. S.; Landen, O. L.; MacGowan, B. J.; Marinak, M. M.; Milovich, J. L.; Moses, E. I. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

2011-05-15T23:59:59.000Z

313

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

SciTech Connect (OSTI)

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

314

A study of ignition of oil shale and char  

SciTech Connect (OSTI)

The ignition characteristics of Fushun, Maoming and Jordan oil shale samples have been determined experimentally by using thermogravimetric analyzer (TGA) and CO/CO{sub 2} analyzer. Their chars have been investigated, too. Two ignition mechanisms for oil shale and shale char are suggested. One is called heterogeneous, according to which, the ignition takes place on the surface of the oil shale and/or shale char sample. Another is called homogeneous, the ignition occurring in the gas phase surrounding the particles. The ignition mechanism occurred mainly depends on the condition of the combustion, physical properties of samples and the rate of volatile release. The experimental equations of ignition for three kinds of oil shale and their char particles (Fushun, Maoming and Jordan) are given. The difference of ignition temperatures for these oil shale and their char particles are compared in terms of chemical compositions and physical properties.

Min, L.; Changshan, L. (Fushun Research Institute of Petroleum and Petrochemicals, Sinopec (CN))

1989-01-01T23:59:59.000Z

315

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

316

IMPLODING IGNITION WAVES. I. ONE-DIMENSIONAL ANALYSIS  

SciTech Connect (OSTI)

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

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

2012-06-20T23:59:59.000Z

317

Visualization of Target Inspection data at the National Ignition Facility  

SciTech Connect (OSTI)

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

318

The National Ignition Facility: enabling fusion ignition for the 21st century  

Science Journals Connector (OSTI)

The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory, when completed in 2008, will contain a 192-beam, 1.8?MJ, 500?TW, ultraviolet laser system together with a 10?m diameter target chamber and room for 100 diagnostics. NIF is housed in a 26?000?m2 environmentally controlled building and is the world's largest and most energetic laser experimental system. NIF provides a scientific centre for the study of inertial confinement fusion and the physics of matter at extreme energy densities and pressures. NIF's energetic laser beams will compress fusion targets to conditions required for thermonuclear burn, liberating more energy than required to initiate the fusion reactions. Other NIF experiments will study physical processes at temperatures and pressures approaching 108?K and 1011?bar, respectively, conditions that exist naturally only in the interior of stars and planets. NIF is currently configured with four laser beams activated in late 2002. These beams are being regularly used for laser performance and physics experiments, and to date nearly 250 system shots have been conducted. NIF's laser beams have generated 106?kJ in 23?ns pulses of infrared light and over 16?kJ in 3.5?ns pulses at the third harmonic (351?nm). A number of target experimental systems are being commissioned in support of experimental campaigns. This paper provides a detailed look at the NIF laser systems, laser and optical performance, and results from laser commissioning shots. We also discuss NIF's high-energy density and inertial fusion experimental capabilities, the first experiments on NIF, and plans for future capabilities of this unique facility.

George H. Miller; Edward I. Moses; Craig R. Wuest

2004-01-01T23:59:59.000Z

319

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

E-Print Network [OSTI]

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

Tillack, Mark

320

Precision Diagnostic System  

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

Precision Diagnostic System For NIF to reach the goal of ignition, it needs to produce highly shaped pulses that are precisely controlled. NIF's precision diagnostic system (PDS)...

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.


321

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

322

Optical and electrical investigations into cathode ignition and diode closure  

SciTech Connect (OSTI)

The temporal behavior of high-power diodes is closely related to the impedance collapse caused by the movement of the cathode and/or anode plasmas. This impedance collapse can be especially problematic when a constant power electron beam is required. This is the case for the very large area (square meters) diodes used to pump the amplifiers within the Aurora KrF laser system. The electron beam technology development program at Los Alamos utilizes the Electron Beam Test Facility (EGTF) to study diode physics in an attempt to better understand the basic phenomenology of ignition and closure. A combination of optical and electric diagnostics has been fielded on the Electron Beam Test Facility to study ignition and closure in large area electron beam diodes. A four-channel framing camera is used to observe the formation of microplasmas on the surface of the cathode and the subsequent movement of these plasmas toward the anode. Additionally, a perveance model is used to extract information about this plasma from voltage and current profiles. Results from the two diagnostics are compared. Closure velocity measurements are presented showing little dependence on applied magnetic field for both velvet and carbon felt emitters. We also report the first observation of the screening effect in large area cold cathode diodes. 13 refs., 11 figs.

Coogan, J.J.; Rose, E.A.; Shurter, R.P.

1991-01-01T23:59:59.000Z

323

Neutron source reconstruction from pinhole imaging at National Ignition Facility  

SciTech Connect (OSTI)

The neutron imaging system at the National Ignition Facility (NIF) is an important diagnostic tool for measuring the two-dimensional size and shape of the neutrons produced in the burning deuterium-tritium plasma during the ignition stage of inertial confinement fusion (ICF) implosions at NIF. Since the neutron source is small (?100 ?m) and neutrons are deeply penetrating (>3 cm) in all materials, the apertures used to achieve the desired 10-?m resolution are 20-cm long, single-sided tapers in gold. These apertures, which have triangular cross sections, produce distortions in the image, and the extended nature of the pinhole results in a non-stationary or spatially varying point spread function across the pinhole field of view. In this work, we have used iterative Maximum Likelihood techniques to remove the non-stationary distortions introduced by the aperture to reconstruct the underlying neutron source distributions. We present the detailed algorithms used for these reconstructions, the stopping criteria used and reconstructed sources from data collected at NIF with a discussion of the neutron imaging performance in light of other diagnostics.

Volegov, P.; Danly, C. R.; Grim, G. P.; Guler, N.; Merrill, F. E.; Wilde, C. H.; Wilson, D. C. [Los Alamos National Laboratory, Los Alamos, New Mexico 87544 (United States)] [Los Alamos National Laboratory, Los Alamos, New Mexico 87544 (United States); Fittinghoff, D. N.; Izumi, N.; Ma, T.; Warrick, A. L. [Livermore National Laboratory, Livermore, California 94550 (United States)] [Livermore National Laboratory, Livermore, California 94550 (United States)

2014-02-15T23:59:59.000Z

324

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

SciTech Connect (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

325

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

326

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

327

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

328

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

SciTech Connect (OSTI)

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

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

2010-06-29T23:59:59.000Z

329

Laser-induced ignition modeling of HMX  

Science Journals Connector (OSTI)

Abstract The laser-induced ignition response of HMX has been investigated using a detailed numerical model. The model is one-dimensional, fully transient, and solves the conservation equations for both the condensed and gas phases. The condensed phase representation includes radiation absorption, solid-phase transitions, melting, evaporation, and distributed semi-global decomposition kinetics. The gas phase utilizes a detailed kinetic mechanism to predict species formation and destruction. Ignition occurs in the gas phase and the flame propagates back toward the surface of the HMX in what is known as the ‘snap-back’ effect. The model then transitions to steady-state combustion. Calculations were performed in which the solid HMX is irradiated with heat fluxes ranging from 50 to 1600 W/cm2. Results are compared to empirical data for the laser-induced ignition of HMX. Good agreement with these data and other steady-state data (burning rate, surface temperature, melt thickness) provide the necessary validation of the developed model.

Karl V. Meredith; Matthew L. Gross; Merrill W. Beckstead

2014-01-01T23:59:59.000Z

330

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

SciTech Connect (OSTI)

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

331

Manifestation of constrained dynamics in a low pressure spark  

E-Print Network [OSTI]

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

Auluck, S K H

2013-01-01T23:59:59.000Z

332

Capsule performance optimization in the National Ignition Campaign  

SciTech Connect (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

333

Capsule Performance Optimization in the National Ignition Campaign  

SciTech Connect (OSTI)

A capsule performance optimization campaign will be conducted at the National Ignition Facility to substantially increase the probability of ignition. 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; MacGowan, B J; Haan, S W; Edwards, J

2009-10-13T23:59:59.000Z

334

High resolution simulations of ignition capsule designs for the National Ignition Facility  

SciTech Connect (OSTI)

Ignition capsule designs for the National Ignition Facility (NIF) [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 443, 2841 (2004)] have continued to evolve in light of improved physical data inputs, improving simulation techniques, and - most recently - experimental data from a growing number of NIF sub-ignition experiments. This paper summarizes a number of recent changes to the cryogenic capsule design and some of our latest techniques in simulating its performance. Specifically, recent experimental results indicated harder x-ray drive spectra in NIF hohlraums than were predicted and used in previous capsule optimization studies. To accommodate this harder drive spectrum, a series of high-resolution 2-D simulations, resolving Legendre mode numbers as high as two thousand, were run and the germanium dopant concentration and ablator shell thicknesses re-optimized accordingly. Simultaneously, the possibility of cooperative or nonlinear interaction between neighboring ablator surface defects has motivated a series of fully 3-D simulations run with the massively parallel HYDRA code. These last simulations include perturbations seeded on all capsule interfaces and can use actual measured shell surfaces as initial conditions. 3-D simulations resolving Legendre modes up to two hundred on large capsule sectors have run through ignition and burn, and higher resolution simulations resolving as high as mode twelve hundred have been run to benchmark high-resolution 2-D runs. Finally, highly resolved 3-D simulations have also been run of the jet-type perturbation caused by the fill tube fitted to the capsule. These 3-D simulations compare well with the more typical 2-D simulations used in assessing the fill tube's impact on ignition. Coupled with the latest experimental inputs from NIF, our improving simulation capability yields a fuller and more accurate picture of NIF ignition capsule performance.

Clark, D S; Haan, S W; Cook, A W; Edwards, M J; Hammel, B A; Koning, J M; Marinak, M M

2011-02-17T23:59:59.000Z

335

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

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

Ignition and Their Impact on Advanced Combustion Engines Joshua D. Taylor - National Renewable Energy Laboratory Stuart Neill, Hailin Li - National Research Council Canada...

336

HEC-DPSSL 2012 Workshop, Directions: National Ignition Facility...  

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

Road Keep left at the fork Destination will be on the right Directions to Lawrence Livermore National Laboratory and the National Ignition Facility can be found on the...

337

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

Office of Environmental Management (EM)

Developing Prediction Limits for Overdispersed Count Data Authors: Elizabeth J. Kelly and Raymond N. Tell Modeling the Number of Ignitions Following an Earthquake:...

338

Advanced CFD Models for High Efficiency Compression Ignition Engines  

Broader source: Energy.gov [DOE]

Advanced CFD models for high efficiency compression-ignition engines can be used to show how turbulence-chemistry interactions influence autoignition and combustion.

339

Synthesizing aluminum particles towards controlling electrostatic discharge ignition sensitivity  

SciTech Connect (OSTI)

Aluminum particles were synthesized with shell thicknesses ranging from 2.7 to 8.3 nm and a constant diameter of 95 nm. These fuel particles were combined with molybdenum trioxide particles and the electrostatic discharge (ESD) sensitivity of the mixture was measured. Results show ignition delay increased as the alumina shell thickness increased. These results correlated with electrical resistivity measurements of the mixture which increased with alumina concentration. A model was developed using COMSOL for ignition of a single Al particle. The ignition delay in the model was consistent with the experimental results suggesting that the primary ESD ignition mechanism is joule heating.

Eric S. Collins; Jeffery P. Gesner; Michelle L. Pantoya; Michael A. Daniels

2014-02-01T23:59:59.000Z

340

Pulsed Laser Ignition Thresholds of Energetic Multilayer Foils  

Science Journals Connector (OSTI)

Ignition thresholds for energetic multilayer foils comprised of aluminum (Al) and platinum (Pt) layers are presented as a function of foil properties for laser pulse durations of 100...

McDonald, Joel P; Picard, Yoosuf N; Yalisove, Steven M; Adams, David P

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

HEC-DPSSL 2012 Workshop, NIF Tour: National Ignition Facility...  

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

Deadline: August 10, 2012 Lawrence Livermore National Laboratory is home to the National Ignition Facility (NIF). NIF is a national resource a unique experimental facility...

342

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

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

Multi-cylinder, turbocharged, common rail, direct injection study in which high ignition quality fuel was found avoid NO X , PM, THC and CO emissions while maintaining...

343

High power fiber delivery for laser ignition applications  

Science Journals Connector (OSTI)

The present contribution provides a concise review of high power fiber delivery research for laser ignition applications. The fiber delivery requirements are discussed in terms of exit...

Yalin, Azer P

2013-01-01T23:59:59.000Z

344

Advanced CFD Models for High Efficiency Compression Ignition...  

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

for high efficiency compression-ignition engines can be used to show how turbulence-chemistry interactions influence autoignition and combustion. p-19raja.pdf More Documents &...

345

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

SciTech Connect (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

346

Investigation of proton focusing and conversion efficiency for proton fast ignition  

E-Print Network [OSTI]

as a step towards laser fusion ignition,” nature, vol. 412,laser in order for the ignition laser to be absorbed in areason being that the ignition laser energy would otherwise

Bartal, Teresa Jean

2012-01-01T23:59:59.000Z

347

The National Ignition Facility and the Promise of Inertial Fusion Energy  

SciTech Connect (OSTI)

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

Moses, E I

2010-12-13T23:59:59.000Z

348

Diesol: an alternative fuel for compression ignition engines  

SciTech Connect (OSTI)

Physical properties including specific gravity, kinematic viscosity, heat of combustion, flash point, cetane number and distillation curves are presented for several blends of No. 2 diesel fuel and soybean oil. The mixture is referred to as Diesol. The soybean oil received a minimal amount of refining by water-washing to remove most of the lecithin type gums. The Diesol fuels were tested in a Cooperative Fuel Research single cylinder diesel test engine to determine the short time engine performance using soybean oil as a diesel fuel extender. Brake specific fuel consumption, volumetric fuel consumption, exhaust smoke opacity and power were determined. Various blends of Diesol were also tested in a multicylinder diesel commercial power system. Results are presented to show the comparison between Diesol blends and diesel fuel. The fuel properties and engine performance test results indicate that soybean oil would be a viable extender of diesel fuel for compression-ignition engines.

Cochran, B.J.; Baldwin, J.D.C.; Daniel, L.R. Jr.

1981-01-01T23:59:59.000Z

349

Determination of trace impurities in zircaloy-2 and tellurium by spark source mass spectrometry  

Science Journals Connector (OSTI)

Determination of trace impurities in zircaloy-2 and tellurium by Spark Source Mass Spectrometry (SSMS) is reported. The advantage of SSMS lies in the fact that along with metallic trace constituents even the n...

K. L. Ramakumar; V. A. Raman; V. L. Sant…

1988-12-01T23:59:59.000Z

350

Systems Alliance, Inc. 34 Loveton Circle  

E-Print Network [OSTI]

Contact: Systems Alliance, Inc. 34 Loveton Circle Sparks, Maryland 21152 Phone: 410.584.0595 / 877-081222a Printed December 30, 2008 This information is ©December 2008 by Systems Alliance, 34 Loveton Alliance, 34 Loveton Circle / Sparks, MD 21152 / 410.584.0595 Table of Contents Table of Contents

Scharfstein, Daniel

351

Recent progress on the Compact Ignition Tokamak (CIT)  

SciTech Connect (OSTI)

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

Ignat, D.W.

1987-01-01T23:59:59.000Z

352

Conceptual design of fast-ignition laser fusion reactor FALCON-D  

Science Journals Connector (OSTI)

A new conceptual design of the laser fusion power plant FALCON-D (Fast-ignition Advanced Laser fusion reactor CONcept with a Dry wall chamber) has been proposed. The fast-ignition method can achieve sufficient fusion gain for a commercial operation (~100) with about 10 times smaller fusion yield than the conventional central ignition method. FALCON-D makes full use of this property and aims at designing with a compact dry wall chamber (5–6?m radius). 1D/2D simulations by hydrodynamic codes showed a possibility of achieving sufficient gain with a laser energy of 400?kJ, i.e. a 40?MJ target yield. The design feasibility of the compact dry wall chamber and the solid breeder blanket system was shown through thermomechanical analysis of the dry wall and neutronics analysis of the blanket system. Moderate electric output (~400?MWe) can be achieved with a high repetition (30?Hz) laser. This dry wall reactor concept not only reduces several difficulties associated with a liquid wall system but also enables a simple cask maintenance method for the replacement of the blanket system, which can shorten the maintenance period. The basic idea of the maintenance method for the final optics system has also been proposed. Some critical R&D issues required for this design are also discussed.

T. Goto; Y. Someya; Y. Ogawa; R. Hiwatari; Y. Asaoka; K Okano; A. Sunahara; T. Johzaki

2009-01-01T23:59:59.000Z

353

Status of the National Ignition Facility project  

SciTech Connect (OSTI)

The ultimate goal of worldwide research in inertial confinement fusion (ICF) is to develop fusion as an inexhaustible, economic, environmentally safe source of electric power. Following nearly thirty years of laboratory and underground fusion experiments, the next step toward this goal is to demonstrate ignition and propagating burn of fusion fuel in the laboratory. The National Ignition Facility(NIF) Project is being constructed at Lawrence Livermore National Laboratory (LLNL), for just this purpose. NIF will use advanced Nd-glass laser technology to deliver 1.8 MJ of 0.35-um laser light in a shaped pulse, several nanoseconds in duration, achieving a peak power of 500 TW. A national community of U.S. laboratories is participating in this project, now in its final design phase. Franceand the United Kingdom are collaborating on development of required technology under bilateral agreements with the US. This paper presents thestatus of the laser design and development of its principal components and optical elements.

Paisner, J.A.; Lowdermilk, W.H.; Boyes, J.D.; Sorem, M.S.; Soures, J.M.

1997-04-01T23:59:59.000Z

354

National Ignition Facility project acquisition plan  

SciTech Connect (OSTI)

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

355

Saffman-Taylor streamers: Mutual finger interaction in spark formation  

Science Journals Connector (OSTI)

Bunches of streamers form the early stages of sparks and lightning but theory presently concentrates on single streamers or on coarse approximations of whole breakdown trees. Here a periodic array of interacting streamer discharges in a strong homogeneous electric field is studied in density or fluid approximation in two dimensions. If the period of the streamer array is small enough, the streamers do not branch, but approach uniform translation. When the streamers are close to the branching regime, the enhanced field at the tip of the streamer is close to 2E?, where E? is the homogeneous field applied between the electrodes. We discuss a moving boundary approximation to the density model. This moving boundary model turns out to be essentially the same as the one for two-fluid Hele-Shaw flows. In two dimensions, this model possesses a known analytical solution. The shape of the two-dimensional interacting streamers in uniform motion obtained from the PDE simulations is actually well fitted by the analytically known “selected Saffman-Taylor finger.” This finding helps to understand streamer interactions and raises new questions on the general theory of finger selection in moving boundary problems.

Alejandro Luque, Fabian Brau, and Ute Ebert

2008-07-11T23:59:59.000Z

356

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

SciTech Connect (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

357

Vacuum arc ignition by penning discharge in a strong magnetic field  

SciTech Connect (OSTI)

Vacuum arc with cathode spots on the cold electrode is widely used as a plasma generator in a such kind of devices like metal ion sources, plasma cathode electron guns, thing films deposition facilities and others. Most vacuum arc devices utilize a high voltage discharge across an insulator surface to provide a trigger plasma which in turn initiates the main arc discharge. Operation of vacuum arc in a repetitively pulsed mode required a stable triggering system for the long time. But with a discharge across the insulators the number of stable pulses is limited by 100,000 or little bit more. The better method for vacuum arc ignition is low pressure discharge. As shown in this paper it is possible to increase the lifetime of the ignition system in 10 times at least, but negative characteristic of this system is a relatively high pressure (about 0.1 mtorr). In some kinds of vacuum arc applications it is impermissible because it leads to the {open_quotes}contamination{close_quotes} of the metal plasma by the gaseous one. In order to decrease the background pressure, using the gas discharge ignition system for vacuum arc, Penning discharge is suggested. The main new feature of this system is an applying the strong magnetic field not only for stabilization of the cathode spot moving and for the rise the high charge states of ions in metal plasma, but also for the essential decrease the lowest point of the background gas pressure when the Penning discharge is still in a stable operation. Under the stable mode of Penning discharge there was always a stable vacuum arc ignition.

Nikolaev, A.G.; Schanin, P.M.; Yushkov, G.Yu. [High Current Electronics Inst., Tomsk (Russian Federation)] [and others

1995-12-31T23:59:59.000Z

358

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

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

359

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

DOE Patents [OSTI]

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

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

1988-01-01T23:59:59.000Z

360

Investigation of ignition of thermoplastics through the Hot Wire Ignition Test  

E-Print Network [OSTI]

. . . . , . . . . , . Ignition Temperature Ranges of PMMA, PE, Nylon and PC ' . . . Plot of Temperature Measurements for Plexiglas 1/16". . . . . . . . . . . . . Plot of Temperature Measurements for Plexiglas 1/8". . . . . . . . . . . . . . . Plot of Temperature Measurements... and Quintiere Materials PMMA Nylon Polyethylene Polypropylene Description Polycast, black, polymethylmeth acr ylate, 2. 5 cm Polypenco, extruded, unfilled, type 6/6, 2. 5 cm Allied Resinous products, Inc. , type tO', 2. 5 cm Poly-Hi, clear, high...

De Araujo, Luiz Claudio Bonilla

1998-01-01T23:59:59.000Z

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.


361

Catalytic ignition of fuel/oxygen/nitrogen mixtures over platinum  

SciTech Connect (OSTI)

Ignition of fuel/oxygen/nitrogen mixtures over platinum wire is experimentally studied by using microcalorimetry and by restricting the flow to the low Reynolds number range so that axisymmetry prevails. The fuels studied are propane, butane, propylene, ethylene, carbon monoxide, and hydrogen. Parameters investigated include flow velocity, fuel type and concentration, and oxygen concentration. The catalytic ignition temperatures of the various fuels are accurately determined over extensive ranges of fuel/oxygen/nitrogen concentrations. Results show two distinctly opposite ignition trends depending on the nature of the fuel. That is, the ignition temperature of lean propane/air and butane/air mixtures decreases as their fuel concentration is increased, while the reverse trend is observed for lean mixtures of propylene, ethylene, carbon monoxide, and hydrogen with air. Furthermore, the ignition of propane depends primarily on fuel concentration, while the ignition of carbon monoxide depends on fuel and oxygen concentrations to a comparable extent. These results are explained on the basis of hierarchical surface adsorption strengths of the different reactants in effecting catalytic ignition. Additional phenomena of interest are observed and discussed.

Cho, P.; Law, C.K.

1986-11-01T23:59:59.000Z

362

Pre-ignition laser ablation of nanocomposite energetic materials  

SciTech Connect (OSTI)

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

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

2013-06-07T23:59:59.000Z

363

Laser ignition of dust clouds INERIS, BP. 2, F-60550 Vemeuil-en-Halatte  

E-Print Network [OSTI]

Laser ignition of dust clouds Ch. PROUST INERIS, BP. 2, F-60550 Vemeuil-en-Halatte ineris-00961863.1051/jp4:20020269 #12;Abstract. In a previous paper [1], the possibility of igniting a combustible dust the scope of the investigated ignition phenomena. In particular a relationship between the standard ignition

Paris-Sud XI, Université de

364

On the mechanism of aluminum ignition in steam explosions  

Science Journals Connector (OSTI)

An available theory [Epstein, M., Fauske, H.K., 1994. A crystallization theory of underwater aluminum ignition. Nucl. Eng. Des. 146, 147–164] of the ignition of aluminum melt drops under water, which is based on the assumption that the aluminum oxide (Al2O3) drop-surface skin first appears in a metastable molten state, is compared with existing experimental data on the ignition of aluminum drops behind shock waves in water [Theofanous, T.G., Chen, X., DiPiazza, P., Epstein, M., Fauske, H.K., 1994. Ignition of aluminum droplets behind shock waves in water, Phys. Fluids 6, 3513–3515]. The predicted and measured ignition temperature of about 1770 K coincides approximately with the spontaneous nucleation temperature of supercooled liquid Al2O3 (1760 K). This suggests that the crystallization of the oxide layer represents a strong ‘barrier’ to aluminum drop ignition under water. Apparently a similar interpretation is applicable to aluminum drop ignition in gaseous oxidizing atmospheres. We conclude from the theory that the low-temperature aluminum ignitions (in the range 1100–1600 K) that have been observed during steam explosions are a consequence of the short aluminum drop oxidation times in this environment relative to the characteristic time for Al2O3 crystallization. Several aspects of the aluminum drop/shock interaction experiments besides ignition are discussed in the paper. In particular, the experiments provide strong evidence that during the course of a vapor explosion metal fragmentation occurs via a thermal mechanism at low pressure and precedes the development of a high-pressure shock.

M Epstein; H.K Fauske; T.G Theofanous

2000-01-01T23:59:59.000Z

365

Instrumentation and controls of an ignited tokamak  

SciTech Connect (OSTI)

The instrumentation and controls (I and C) of an ignited plasma magnetically confined in a tokamak configuration needs increased emphasis in the following areas: (1) physics implications for control; (2) plasma shaping/position control; and (3) control to prevent disruptive instabilities. This document reports on the FY 1979 efforts in these and other areas. Also presented are discusssions in the areas of: (1) diagnostics suitable for the Engineering Test Facility (ETF); and (2) future research and development (R and D) needs. The appendices focus attention on some preliminary ideas about the measurement of the deuteron-triton (D-T) ratio in the plasma, synchrotron radiation, and divertor control. Finally, an appendix documenting the thermal consequences to the first wall of a MPD is presented.

Becraft, W.R.; Golzy, J.; Houlberg, W.A.; Kukielka, C.A.; Onega R.J.; Raju, G.V.S.; Stone, R.S.

1980-10-01T23:59:59.000Z

366

Director of the National Ignition Facility, Lawrence Livermore National  

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

367

IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 39, NO. 12, DECEMBER 2011 3307 Microwave-Plasma-Coupled Re-Ignition of  

E-Print Network [OSTI]

-ignition phenomenon is observed when fuel/ oxidizer is re-introduced into an atmospheric-pressure plasma dischargeIEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 39, NO. 12, DECEMBER 2011 3307 Microwave-Plasma generated by cutting off the gas flow in a re-entrant microwave-plasma applicator system used for plasma

Lee, Tonghun

368

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

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

369

Effects of Fuel Ignition Quality on Critical Equivalence Ratio for Autoignition  

Science Journals Connector (OSTI)

This hypothesis is based on the work of Musculus et al.,(2) who introduced the concept of a “critical” equivalence ratio (?), below which fuel in localized regions of the chamber is a potential source for incomplete combustion. ... The evaporative steam cooling system, used to maintain water jacket temperatures of the engine in the standard CFR engine design,(12) was replaced with an 8 L 1000 W refrigerated/heating circulator. ... Musculus et al.,(2) who first presented the concept of critical ?, stated that “UHC emissions may arise from jets that ignite before EOI (negative ignition dwell) if the mixtures near the injector become too lean either to autoignite in the time available or to support propagation of the downstream reaction zone into the near-injector region.” ...

Gregory K. Lilik; André L. Boehman

2013-02-11T23:59:59.000Z

370

Frictionally induced ignition processes in drop and skid tests  

SciTech Connect (OSTI)

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

371

Ignition of gas mixtures containing natural gas and oxygen  

Science Journals Connector (OSTI)

Gases released during the thermal treatment of a coal-gas suspension exhibit a strong inhibiting effect on the self-ignition of natural gas but have a minor influence on the...

N. M. Rubtsov; B. S. Seplyarskii; G. I. Tsvetkov…

2010-01-01T23:59:59.000Z

372

The National Ignition Facility and Laser Fusion Energy  

Science Journals Connector (OSTI)

This talk provides an update of the NIC on the National Ignition Facility at the Lawrence Livermore National Laboratory and the roadmap to demonstrate laser fusion as a viable source...

Moses, E I

373

National Ignition Facility & Photon Science HOW NIF WORKS  

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

NIF WORKS beam me up: how niF works In the National Ignition Facility (NIF), 192 laser beams travel a long path, about 1,500 meters, from their birth at the master oscillator-a...

374

Detonation along laser generated micropinch for fast ignition  

E-Print Network [OSTI]

The proposed fast ignition of highly compressed deuterium-tritium (DT) targets by petawatt lasers requires energy of about 100kJ. To lower the power of the laser, it is proposed to accomplish fast ignition with two lasers, one with lower power in the infrared, and a second one with high power in the visible to ultraviolet region. The infrared laser of lower power shall by its radiation pressure drive a large current in a less than solid density plasma placed inside a capillary, while the second high power-shorter wave length-laser shall ignite at one end of the capillary a magnetic field supported thermonuclear detonation wave in a blanket made from solid DT along the outer surface of the capillary. The other end of the capillary, together with its DT blanket, is stuck in the DT target, where following the compression of the target the detonation wave ignites the target.

Winterberg, F

2008-01-01T23:59:59.000Z

375

Laser-Matter Interaction Above the Plasma Ignition Threshold Intensity  

Science Journals Connector (OSTI)

In this chapter we present the process of laser-matter interaction above the plasma ignition threshold intensity. The physics of the pulsed laser ablation process at high intensities is very complex since it invo...

Mihai Stafe; Aurelian Marcu; Niculae N. Puscas

2014-01-01T23:59:59.000Z

376

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

377

Fast ignition of fusion targets by laser-driven electrons  

E-Print Network [OSTI]

We present hybrid PIC simulations of fast electron transport and energy deposition in pre-compressed fusion targets, taking full account of collective magnetic effects and the hydrodynamic response of the background plasma. Results on actual ignition of an imploded fast ignition configuration are shown accounting for the increased beam divergence found in recent experiments [J.S. Green et al., Phys. Rev. Lett. 100, 015003 (2008)] and the reduction of the electron kinetic energy due to profile steepening predicted by advanced PIC simulations [B. Chrisman et al. Phys. Plasmas 15, 056309 (2008)]. Target ignition is studied as a function of injected electron energy, distance of cone-tip to dense core, initial divergence and kinetic energy of the relativistic electron beam. We found that beam collimation reduces substantially the ignition energies of the cone-guided fuel configuration assumed here.

Honrubia, J J

2008-01-01T23:59:59.000Z

378

Laser-Matter Interaction Below the Plasma Ignition Threshold Intensity  

Science Journals Connector (OSTI)

In this chapter we present the process of laser-matter interaction below the plasma ignition threshold intensity. When the high power laser radiation characterized by electric field intensities around ...

Mihai Stafe; Aurelian Marcu; Niculae N. Puscas

2014-01-01T23:59:59.000Z

379

High Fidelity Modeling of Premixed Charge Compression Ignition Engines  

Broader source: Energy.gov [DOE]

Most accurate and detailed chemical kinetic models for fuels of practical interest to engine manufacturers and fuels developers are applied for high fidelity engine analysis of premixed charge compression ignition engines.

380

Plasma-assisted ignition and deflagration-to-detonation transition  

Science Journals Connector (OSTI)

...Forman A. Williams Plasma-assisted ignition...correspondence ( astariko@princeton.edu ). 1 Mechanical...Aerospace Engineering, Princeton University, , Princeton, NJ-08544, USA...Non-equilibrium plasma demonstrates great...

2012-01-01T23:59:59.000Z

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.


381

Theory of Fast Electron Transport for Fast Ignition  

E-Print Network [OSTI]

Fast Ignition Inertial Confinement Fusion is a variant of inertial fusion in which DT fuel is first compressed to high density and then ignited by a relativistic electron beam generated by a fast (laser pulse, which is usually brought in to the dense plasma via the inclusion of a re-entrant cone. The transport of this beam from the cone apex into the dense fuel is a critical part of this scheme, as it can strongly influence the overall energetics. Here we review progress in the theory and numerical simulation of fast electron transport in the context of Fast Ignition. Important aspects of the basic plasma physics, descriptions of the numerical methods used, a review of ignition-scale simulations, and a survey of schemes for controlling the propagation of fast electrons are included. Considerable progress has taken place in this area, but the development of a robust, high-gain FI `point design' is still an ongoing challenge.

Robinson, A P L; Davies, J R; Gremillet, L; Honrubia, J J; Johzaki, T; Kingham, R J; Sherlock, M; Solodov, A A

2013-01-01T23:59:59.000Z

382

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

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

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

383

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

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

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,

384

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

385

Optimally Controlled Flexible Fuel Powertrain System  

SciTech Connect (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

386

Management Of Experiments And Data At The National Ignition Facility  

SciTech Connect (OSTI)

Experiments, or 'shots', conducted at the National Ignition Facility (NIF) are discrete events that occur over a very short time frame (tens of nanoseconds) separated by many hours. Each shot is part of a larger campaign of shots to advance scientific understanding in high-energy-density physics. In one campaign, scientists use energy from the 192-beam, 1.8-Megajoule pulsed laser in the NIF system to symmetrically implode a hydrogen-filled target, thereby creating conditions similar to the interior of stars in a demonstration of controlled fusion. Each NIF shot generates gigabytes of data from over 30 diagnostics that measure optical, x-ray, and nuclear phenomena from the imploding target. We have developed systems to manage all aspects of the shot cycle. Other papers will discuss the control of the lasers and targets, while this paper focuses on the setup and management of campaigns and diagnostics. Because of the low duty cycle of shots, and the thousands of adjustments for each shot (target type, composition, shape; laser beams used, their power profiles, pointing; diagnostic systems used, their configuration, calibration, settings) it is imperative that we accurately define all equipment prior to the shot. Following the shot, and capture of the data by the automatic control system, it is equally imperative that we archive, analyze and visualize the results within the required 30 minutes post-shot. Results must be securely archived, approved, web-visible and downloadable in order to facilitate subsequent publication. To-date NIF has successfully fired over 2,500 system shots, as well as thousands of test firings and dry-runs. We will present an overview of the highly-flexible and scalable campaign management systems and tools employed at NIF that control experiment configuration of the facility all the way through presentation of analyzed results.

Azevedo, S; Casey, A; Beeler, R; Bettenhausen, R; Bond, E; Chandrasekaran, H; Foxworthy, C; Hutton, M; Krammen, J; Liebman, J; Marsh, A; Pannell, T; Rhodes, J; Tappero, J; Warrick, A

2011-03-18T23:59:59.000Z

387

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

SciTech Connect (OSTI)

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

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

2014-05-15T23:59:59.000Z

388

National Ignition Facility Project Site Safety Program  

SciTech Connect (OSTI)

This Safety Program for the National Ignition Facility (NIF) presents safety protocols and requirements that management and workers shall follow to assure a safe and healthful work environment during activities performed on the NIF Project site. The NIF Project Site Safety Program (NPSSP) requires that activities at the NIF Project site be performed in accordance with the ''LLNL ES&H Manual'' and the augmented set of controls and processes described in this NIF Project Site Safety Program. Specifically, this document: (1) Defines the fundamental NIF site safety philosophy. (2) Defines the areas covered by this safety program (see Appendix B). (3) Identifies management roles and responsibilities. (4) Defines core safety management processes. (5) Identifies NIF site-specific safety requirements. This NPSSP sets forth the responsibilities, requirements, rules, policies, and regulations for workers involved in work activities performed on the NIF Project site. Workers are required to implement measures to create a universal awareness that promotes safe practice at the work site and will achieve NIF management objectives in preventing accidents and illnesses. ES&H requirements are consistent with the ''LLNL ES&H Manual''. This NPSSP and implementing procedures (e.g., Management Walkabout, special work procedures, etc.,) are a comprehensive safety program that applies to NIF workers on the NIF Project site. The NIF Project site includes the B581/B681 site and support areas shown in Appendix B.

Dun, C

2003-09-30T23:59:59.000Z

389

A polar-drive-ignition design for the National Ignition Facility  

SciTech Connect (OSTI)

Polar drive [Skupsky et al., Phys. Plasmas 11, 2763 (2004)] will enable direct-drive experiments to be conducted on the National Ignition Facility (NIF) [Miller et al., Opt. Eng. 43, 2841 (2004)], while the facility is configured for x-ray drive. A polar-drive ignition design for the NIF has been developed that achieves a gain of 32 in two-dimensional (2-D) simulations, which include single- and multiple-beam nonuniformities and ice and outer-surface roughness. This design requires both single-beam UV polarization smoothing and one-dimensional (1-D) multi-frequency modulator (MFM) single-beam smoothing to achieve the required laser uniformity. The multi-FM smoothing is employed only during the low-intensity portion of the laser pulse, allowing for the use of sufficient smoothing-by-spectral-dispersion bandwidth while maintaining safe laser operations during the high-intensity part of the pulse. This target is robust to all expected sources of perturbations.

Collins, T. J. B.; Marozas, J. A.; Anderson, K. S.; Craxton, R. S.; Delettrez, J. A.; Goncharov, V. N.; Harding, D. R.; Marshall, F. J.; McCrory, R. L.; McKenty, P. W.; Radha, P. B.; Shvydky, A.; Skupsky, S.; Zuegel, J. D. [Laboratory for Laser Energetics, 250E. River Rd, Rochester, New York 14623 (United States); Betti, R.; Meyerhofer, D. D. [Laboratory for Laser Energetics, 250E. River Rd, Rochester, New York 14623 (United States); Departments of Mechanical Engineering and Physics, University of Rochester, Rochester, New York 14623 (United States); Fusion Science Center, University of Rochester, Rochester, New York 14623 (United States)

2012-05-15T23:59:59.000Z

390

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

SciTech Connect (OSTI)

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

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

2014-10-01T23:59:59.000Z

391

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

E-Print Network [OSTI]

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

Yang, Zong-Liang

392

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

SciTech Connect (OSTI)

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

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

2014-05-15T23:59:59.000Z

393

Flame kernel characterization of laser ignition of natural gas–air mixture in a constant volume combustion chamber  

Science Journals Connector (OSTI)

In this paper, laser-induced ignition was investigated for compressed natural gas–air mixtures. Experiments were performed in a constant volume combustion chamber, which simulate end of the compression stroke conditions of a SI engine. This chamber simulates the engine combustion chamber conditions except turbulence of air–fuel mixture. It has four optical windows at diametrically opposite locations, which are used for laser ignition and optical diagnostics simultaneously. All experiments were conducted at 10 bar chamber pressure and 373 K chamber temperature. Initial stage of combustion phenomena was visualized by employing Shadowgraphy technique using a high speed CMOS camera. Flame kernel development of the combustible fuel–air mixture was investigated under different relative air–fuel ratios (?=1.2?1.7) and the images were interrogated for temporal propagation of flame front. Pressure-time history inside the combustion chamber was recorded and analyzed. This data is useful in characterizing the laser ignition of natural gas–air mixture and can be used in developing an appropriate laser ignition system for commercial use in SI engines.

Dhananjay Kumar Srivastava; Kewal Dharamshi; Avinash Kumar Agarwal

2011-01-01T23:59:59.000Z

394

Methanol vaporization and injection system for internal combustion engine  

SciTech Connect (OSTI)

An engine equipped with an alcohol vaporization injection system operates as a four stroke cycle diesel engine that transfers the heat of exiting exhaust gases and cylinder head walls to the fuel. The engine runs on alcohol. The alcohol becomes vaporized and its pressure is high enough so that when a valve is opened between the high pressure fuel line and the combustion chamber (when it is at the peak of its compression ratio) enough alcohol will enter the combustion chamber to allow proper combustion. The overall advantages to this type of alcohol vaporization injection system is that it adds relatively few new mechanisms to the spark ignition four cycle internal combustion engine to enable it to operate as a diesel engine with a high thermal efficiency. This alcohol injection system exploits the engine's need for greater volumes of alcohol caused by the alcohol's relatively low heat of combustion (When compared to gasoline) by using this greater volume of fuel to return greater quantities of heat back to the engine to a much greater degree than other fuels can.

Bayley, R.I.

1980-05-06T23:59:59.000Z

395

Evaluating the ignition sensitivity of thermal battery heat pellets  

SciTech Connect (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

396

THE AUTOIGNITION OF CYCLOPENTANE IN AN IGNITION QUALITY TESTER  

SciTech Connect (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

397

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

Broader source: Energy.gov [DOE]

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

398

Ignition characteristics of methane/air premixed mixture by microwave-enhanced laser-induced breakdown plasma  

Science Journals Connector (OSTI)

A microwave-enhanced plasma generation technique was combined with laser-induced ignition to improve ignition characteristics. A locally intensified microwave field was formed near the...

Nishiyama, Atsushi; Moon, Ahsa; Ikeda, Yuji; Hayashi, Jun; Akamatsu, Fumiteru

2013-01-01T23:59:59.000Z

399

The influence of feedstock drying on the performance and economics of a biomass gasifier–engine CHP system  

Science Journals Connector (OSTI)

The need to dry biomass feedstocks before they can be gasified can place a large energy and capital cost burden on small-to-medium scale biomass gasification plants for the production of heat and power. Drying may not always be unavoidable, but as biomass moisture content to the gasifier increases, the quality of the product gas deteriorates along with the overall performance of the whole system. This system modelling study addresses the influence of feedstock moisture content both before and after drying on the performance and cost of a biomass gasifier–engine system for combined heat and power at a given scale and feedstock cost. The scale range considered 0.5–3.0 MWe. The system comprises an updraft gasifier with external thermal and catalytic tar cracking reactors, gas clean-up and a spark-ignition gas engine. A spreadsheet-based system model is constructed, with individual worksheets corresponding to sub-models of system components, and a number of drying technology options and modes of operation are examined. Wherever possible, data supplied by manufacturers or taken from real systems is used in the construction of the sub-models, particularly in the derivation of cost functions.

J.G. Brammer; A.V. Bridgwater

2002-01-01T23:59:59.000Z

400

Planetary and Protostellar Nuclear Fission: Implications for Planetary Change, Stellar Ignition and Dark Matter  

Science Journals Connector (OSTI)

...changes in the geomagnetic field. The concept that thermonuclear fusion reactions in stars are ignited by nuclear fission...protostellar nuclear fission reactors failed to ignite thermonuclear fusion reactions. The Royal Society is collaborating...

1994-01-01T23:59:59.000Z

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.


401

The effects of EGR and ignition timing on emissions of GDI engine  

Science Journals Connector (OSTI)

The effects of EGR and ignition timing on engine emissions and combustion were studied through an experiment carried out on an air-guided GDI engine. The test results showed that the ignition timing significantly...

LiFeng Zhao; XiuMin Yu; DingChao Qian; Wei Dong…

2013-12-01T23:59:59.000Z

402

Laser ablation ignition of premixed methane and oxygen-enriched air mixtures using a tantalum target  

Science Journals Connector (OSTI)

We report the laser ablation ignition of premixed methane and oxygen-enriched air mixtures using a tantalum target. The minimum laser pulse energy (MPE) of the ablation ignition was...

Li, Xiaohui; Yu, Xin; Fan, Rongwei; Yu, Yang; Liu, Chang; Chen, Deying

2014-01-01T23:59:59.000Z

403

Laser-induced ignition and combustion in a SI engine with direct injection  

Science Journals Connector (OSTI)

Laser-induced ignition has shown huge advantages for the combustion ... (KIT) to investigate the potential of the laser-induced ignition. The emphasis was on improving combustion initiation...

Dipl.-Ing. Volker Gross; Dr.-Ing. Heiko Kubach…

2010-07-01T23:59:59.000Z

404

Diagnosing and controlling mix in National Ignition Facility implosion experiments  

SciTech Connect (OSTI)

High mode number instability growth of ''isolated defects'' on the surfaces of National Ignition Facility [Moses et al., Phys. Plasmas 16, 041006 (2009)] capsules can be large enough for the perturbation to penetrate the imploding shell, and produce a jet of ablator material that enters the hot-spot. Since internal regions of the CH ablator are doped with Ge, mixing of this material into the hot-spot results in a clear signature of Ge K-shell emission. Evidence of jets entering the hot-spot has been recorded in x-ray images and spectra, consistent with simulation predictions [Hammel et al., High Energy Density Phys. 6, 171 (2010)]. Ignition targets have been designed to minimize instability growth, and capsule fabrication improvements are underway to reduce ''isolated defects.'' An experimental strategy has been developed where the final requirements for ignition targets can be adjusted through direct measurements of mix and experimental tuning.

Hammel, B. A.; Scott, H. A.; Cerjan, C.; Clark, D. S.; Edwards, M. J.; Glenzer, S. H.; Haan, S. W.; Izumi, N.; Koch, J. A.; Landen, O. L.; Langer, S. H.; Smalyuk, V. A.; Suter, L. J. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Regan, S. P.; Epstein, R. [University of Rochester, Laboratory for Laser Energetics, Rochester, New York 14623 (United States); Kyrala, G. A.; Wilson, D. C. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Peterson, K. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)

2011-05-15T23:59:59.000Z

405

WILDFIRE IGNITION RESISTANCE ESTIMATOR WIZARD SOFTWARE DEVELOPMENT REPORT  

SciTech Connect (OSTI)

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

406

Ignition Delay Times of Kerosene(Jet-A)/Air Mixtures  

E-Print Network [OSTI]

Ignition of Jet-A/air mixtures was studied behind reflected shock waves. Heating of shock tube at temperature of 150 C was used to prepare a homogeneous fuel mixture. Ignition delay times were measured from OH emission at 309 nm and from absorption of He-Ne laser radiation at 3.3922 micrometers. The conditions behind shock waves were calculated by one-dimensional shock wave theory from initial conditions T1, P1, mixture composition and incident shock wave velocity. The ignition delay times were obtained at two fixed pressures 10, 20 atm for lean, stoichiometric and rich mixtures (ER=0.5, 1, 2) at an overall temperature range of 1040-1380 K.

Zhukov, V P; Starikovskii, A Yu

2012-01-01T23:59:59.000Z

407

Shock timing on the National Ignition Facility: First Experiments  

SciTech Connect (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

408

Ion beam requirements for fast ignition of inertial fusion targets  

E-Print Network [OSTI]

Ion beam requirements for fast ignition are investigated by numerical simulation taking into account new effects such as ion beam divergence not included before. We assume that ions are generated by the TNSA scheme in a curved foil placed inside a re-entrant cone and focused on the cone apex or beyond. From the focusing point to the compressed core ions propagate with a given divergence angle. Ignition energies are obtained for two compressed fuel configurations heated by proton and carbon ion beams. The dependence of the ignition energies on the beam divergence angle and on the position of the ion beam focusing point have been analysed. Comparison between TNSA and quasi-monoenergetic ions is also shown.

Honrubia, J J

2015-01-01T23:59:59.000Z

409

Reconfigurable Assembly Station for Precision Manufacture of Nuclear Fusion Ignition Targets  

SciTech Connect (OSTI)

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

410

A TUTORIAL ON IGNITION AND GAIN FOR SMALL FUSION TARGETS  

SciTech Connect (OSTI)

Nuclear fusion was discovered experimentally in 1933-34 and other charged particle nuclear reactions were documented shortly thereafter. Work in earnest on the fusion ignition problem began with Edward Teller's group at Los Alamos during the war years. His group quantified all the important basic atomic and nuclear processes and summarized their interactions. A few years later, the success of the early theory developed at Los Alamos led to very successful thermonuclear weapons, but also to decades of unsuccessful attempts to harness fusion as an energy source of the future. The reasons for this history are many, but it seems appropriate to review some of the basics with the objective of identifying what is essential for success and what is not. This tutorial discusses only the conditions required for ignition in small fusion targets and how the target design impacts driver requirements. Generally speaking, the driver must meet the energy, power and power density requirements needed by the fusion target. The most relevant parameters for ignition of the fusion fuel are the minimum temperature and areal density (rhoR), but these parameters set secondary conditions that must be achieved, namely an implosion velocity, target size and pressure, which are interrelated. Despite the apparent simplicity of inertial fusion targets, there is not a single mode of fusion ignition, and the necessary combination of minimum temperature and areal density depends on the mode of ignition. However, by providing a magnetic field of sufficient strength, the conditions needed for fusion ignition can be drastically altered. Magnetized target fusion potentially opens up a vast parameter space between the extremes of magnetic and inertial fusion.

Kirkpatrick, R. C. [Los Alamos National Laboratory, Los Alamos, NM 087545 (United States)

2009-07-26T23:59:59.000Z

411

National Ignition Facility core x-ray streak camera  

SciTech Connect (OSTI)

The National Ignition Facility (NIF) core x-ray streak camera will be used for laser performance verification experiments as well as a wide range of physics experiments in the areas of high-energy-density science, inertial confinement fusion, and basic science. The x-ray streak camera system is being designed to record time-dependent x-ray emission from NIF targets using an interchangeable family of snouts for measurements such as one-dimensional (1D) spatial imaging or spectroscopy. the NIF core x-ray streak camera will consist of an x-ray-sensitive photocathode that detects x rays with 1D spatial resolution coupled to an electron streak tube to detect a continuous time history of the x rays incident on the photocathode over selected time periods. A charge-coupled-device (CCD) readout will record the signal from the streak tube. The streak tube, CCD, and associated electronics will reside in an electromagnetic interference, and electromagnetic pulse protected, hermetically sealed, temperature-controlled box whose internal pressure is approximately 1 atm. The streak tube itself will penetrate through the wall of the box into the target chamber vacuum. We are working with a goal of a spatial resolution of 15 lp/mm with 50% contrast transfer function at the photocathode and adjustment sweep intervals of 1--50 ns. The camera spectral sensitivity extends from soft x rays to 20 keV x rays, with varying quantum efficiency based on photocathode selection. The system will have remote control, monitoring, and Ethernet communications through an embedded controller. The core streak camera will be compatible with the instrument manipulators at the OMEGA (University of Rochester) and NIF facilities.

Kimbrough, J. R.; Bell, P. M.; Christianson, G. B.; Lee, F. D.; Kalantar, D. H.; Perry, T. S.; Sewall, N. R.; Wootton, A. J.

2001-01-01T23:59:59.000Z

412

Ignition and combustion drive by powerful laser radiation acting on a water surface  

Science Journals Connector (OSTI)

The ignition and combustion effects in water vapor generated...2-laser radiation on a water surface are investigated...

G. I. Kozlov; V. A. Kuznetsov

413

Features of a point design for fast ignition  

SciTech Connect (OSTI)

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

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

2009-10-26T23:59:59.000Z

414

Progress toward Ignition with Noncryogenic Double-Shell Capsules  

SciTech Connect (OSTI)

Inertial confinement fusion implosions using capsules with two concentric shells separated by a low density region (double shells) are reported which closely follow one dimensional (1D) radiatively driven hydrodynamics simulations. Capsule designs which mitigate Au M -band radiation asymmetries appear to correspond more closely to 1D simulations than targets lacking mitigation of hohlraum drive M -band nonuniformities. One capsule design achieves over 50% of the unperturbed 1D calculated yield at a convergence ratio of 25.5, comparable to that of a double-shell design for an ignition capsule at the National Ignition Facility. (c) 2000 The American Physical Society.

Varnum, W. S.; Delamater, N. D.; Evans, S. C.; Gobby, P. L.; Moore, J. E.; Wallace, J. M.; Watt, R. G.; Colvin, J. D.; Turner, R.; Glebov, V. (and others) [and others

2000-05-29T23:59:59.000Z

415

High Performance Imaging Streak Camera for the National Ignition Facility  

SciTech Connect (OSTI)

An x-ray streak camera platform has been characterized and implemented for use at the National Ignition Facility. The camera has been modified to meet the experiment requirements of the National Ignition Campaign and to perform reliably in conditions that produce high EMI. A train of temporal UV timing markers has been added to the diagnostic in order to calibrate the temporal axis of the instrument and the detector efficiency of the streak camera was improved by using a CsI photocathode. The performance of the streak camera has been characterized and is summarized in this paper. The detector efficiency and cathode measurements are also presented.

Opachich, Y. P. [LLNL; Kalantar, D. [LLNL; MacPhee, A. [LLNL; Holder, J. [LLNL; Kimbrough, J. [LLNL; Bell, P. M. [LLNL; Bradley, D. [LLNL; Hatch, B. [LLNL; Brown, C. [LLNL; Landen, O. [LLNL; Perfect, B. H. [LLNL, HMC; Guidry, B. [LLNL; Mead, A. [NSTec; Charest, M. [NSTec; Palmer, N. [LLNL; Homoelle, D. [LLNL; Browning, D. [LLNL; Silbernagel, C. [NSTec; Brienza-Larsen, G. [NSTec; Griffin, M. [NSTec; Lee, J. J. [NSTec; Haugh, M. J. [NSTec

2012-12-01T23:59:59.000Z

416

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

417

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

E-Print Network [OSTI]

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

418

Time-dependent laser ignition of a combustible stagnant boundary layer  

Science Journals Connector (OSTI)

......research-article Articles Time-dependent laser ignition of a combustible stagnant boundary...55,257-268 Time-dependent laser ignition of a combustible stagnant boundary...examines the conditions for laser ignition of a number of industrial gases......

J. ADLER

1995-12-01T23:59:59.000Z

419

Initial experiments on the shock-ignition inertial confinement fusion concepta...  

E-Print Network [OSTI]

ignition is a concept for direct-drive laser inertial confinement fusion ICF Refs. 1­3 that was recently for conven- tional ignition to occur. Then a strong shock wave launched at the end of the laser pulseInitial experiments on the shock-ignition inertial confinement fusion concepta... W. Theobald,1,b R

420

Plasma channel from EP beam Direct-drive ignition is the main thrust in LLE  

E-Print Network [OSTI]

ignition and radiography I2094 The OMEGA laser at the University of Rochester's Laboratory for LaserPlasma channel from EP beam #12;Direct-drive ignition is the main thrust in LLE fusion research activities I2092 · FusionresearchatLLEisfocusedonbuildingthefoundations for a direct-drive­ignition

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

Capsule implosion optimization during the indirect-drive National Ignition Campaign  

E-Print Network [OSTI]

and systematic uncertainties in setting the key ignition laser and target parameters due to residual measurement. INTRODUCTION A. Indirect-drive design The National Ignition Facility (NIF)1 is a 192 beam, 1.8 MJ 0.35 lm laserCapsule implosion optimization during the indirect-drive National Ignition Campaign O. L. Landen,1

422

A metamodeling approach for studying ignition target robustness in a highly dimensional parameter space  

E-Print Network [OSTI]

-up, kinetic energy ignition margin, laser-plasma instabilities, etc. As there are several design parametersA metamodeling approach for studying ignition target robustness in a highly dimensional parameter designed to ignite their central hot spots and burn. Changes in the optimal implosion could reduce

Garnier, Josselin

423

Distributed Feedback Fiber Laser The Heart of the National Ignition Facility  

SciTech Connect (OSTI)

The National Ignition Facility (NIF) is a world-class laser fusion machine that is currently under construction at Lawrence Livermore National Laboratory (LLNL). The 192 laser beams that converge on the target at the output of the NIF laser system originate from a low power fiber laser in the Master Oscillator Room (MOR). The MOR is responsible for generating the single pulse that seeds the entire NIF laser system. This single pulse is phase-modulated to add bandwidth, and then amplified and split into 48 separate beam lines all in single-mode polarizing fiber. Before leaving the MOR, each of the 48 output beams are temporally sculpted into high contrast shapes using Arbitrary Waveform Generators. The 48 output beams of the MOR are amplified in the Preamplifier Modules (PAMs), split and amplified again to generate 192 laser beams. The 192 laser beams are frequency converted to the third harmonic and then focused at the center of a 10-meter diameter target chamber. The MOR is an all fiber-based system utilizing highly reliable Telecom-Industry type hardware. The nearly 2,000,000 joules of energy at the output of the NIF laser system starts from a single fiber oscillator that fits in the palm of your hand. This paper describes the design and performance of the laser source that provides the precision light to the National Ignition Facility. Shown below is a simplified diagram illustrating the MOR's basic functions.

Browning, D F; Erbert, G V

2003-12-01T23:59:59.000Z

424

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...

Lee, Joori

2013-08-01T23:59:59.000Z

425

Fast ignition: Dependence of the ignition energy on source and target parameters for particle-in-cell-modelled energy and angular distributions of the fast electrons  

SciTech Connect (OSTI)

The energy and angular distributions of the fast electrons predicted by particle-in-cell (PIC) simulations differ from those historically assumed in ignition designs of the fast ignition scheme. Using a particular 3D PIC calculation, we show how the ignition energy varies as a function of source-fuel distance, source size, and density of the pre-compressed fuel. The large divergence of the electron beam implies that the ignition energy scales with density more weakly than the ?{sup ?2} scaling for an idealized beam [S. Atzeni, Phys. Plasmas 6, 3316 (1999)], for any realistic source that is at some distance from the dense deuterium-tritium fuel. Due to the strong dependence of ignition energy with source-fuel distance, the use of magnetic or electric fields seems essential for the purpose of decreasing the ignition energy.

Bellei, C.; Divol, L.; Kemp, A. J.; Key, M. H.; Larson, D. J.; Strozzi, D. J.; Marinak, M. M.; Tabak, M.; Patel, P. K. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States)] [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States)

2013-05-15T23:59:59.000Z

426

Ignition and Burn in a Small Magnetized Fuel Target  

E-Print Network [OSTI]

LASNEX calculations of a small magnetized target show high gain at a velocity significantly lower than needed for unmagnetized targets. Its cryogenic fuel layer appears to be raised to an equilibrium ignition temperature of about 2 keV by the radiation from the burning magnetized fuel.

Kirkpatrick, Ronald C

2014-01-01T23:59:59.000Z

427

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.

428

National Ignition Facility faces an uncertain future David Kramer  

E-Print Network [OSTI]

-member user group, with 22% of its members coming from host Lawrence Livermore National Laboratory (LLNL 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

429

Semiconductor bridge: A plasma generator for the ignition of explosives  

SciTech Connect (OSTI)

Small metal bridgewires are commonly used to ignite energetic powders such as pyrotechnics, propellants, and primary or secondary explosives. In this paper we describe a new means for igniting explosive materials using a semiconductor bridge (SCB). When driven with a short (20 ..mu..s), low-energy pulse (less than 3.5 mJ), the SCB produces a hot plasma that ignites explosives. The SCB, a heavily n-doped silicon film, typically 100 ..mu..m long by 380 ..mu..m wide by 2 ..mu..m thick, is 30 times smaller in volume than a conventional bridgewire. SCB devices produce a usable explosive output in a few tens of microseconds and operate at one-tenth the input energy of metal bridgewires. In spite of the low energies for ignition, SCB devices are explosively safe. We describe SCB processing and experiments evaluating SCB operation. Also discussed are the SCB vaporization process, plasma formation, optical spectra from the discharge, heat transfer mechanisms from the SCB to the explosive powders, and SCB device applications.

Benson, D.A.; Larsen, M.E.; Renlund, A.M.; Trott, W.M.; Bickes R.W. Jr.

1987-09-01T23:59:59.000Z

430

Semiconductor bridge: A plasma generator for the ignition of explosives  

Science Journals Connector (OSTI)

Small metal bridgewires are commonly used to ignite energetic powders such as pyrotechnics propellants and primary or secondary explosives. In this paper we describe a new means for igniting explosive materials using a semiconductor bridge (SCB). When driven with a short (20 ?s) low?energy pulse (less than 3.5 mJ) the SCB produces a hot plasma that ignites explosives. The SCB a heavily n?doped silicon film typically 100 ?m long by 380 ?m wide by 2 ?m thick is 30 times smaller in volume than a conventional bridgewire. SCB devices produce a usable explosive output in a few tens of microseconds and operate at one?tenth the input energy of metal bridgewires. In spite of the low energies for ignition SCB devices are explosively safe. We describe SCB processing and experiments evaluating SCB operation. Also discussed are the SCB vaporization process plasma formation optical spectra from the discharge heat transfer mechanisms from the SCB to the explosive powders and SCB device applications.

D. A. Benson; M. E. Larsen; A. M. Renlund; W. M. Trott; R. W. Bickes Jr.

1987-01-01T23:59:59.000Z

431

Transverse liquid fuel jet breakup, burning, and ignition  

SciTech Connect (OSTI)

An analytical/numerical study of the breakup, burning, and ignition of liquid fuels injected transversely into a hot air stream is conducted. The non-reacting liquid jet breakup location is determined by the local sonic point criterion first proposed by Schetz, et al. (1980). Two models, one employing analysis of an elliptical jet cross-section and the other employing a two-dimensional blunt body to represent the transverse jet, have been used for sonic point calculations. An auxiliary criterion based on surface tension stability is used as a separate means of determining the breakup location. For the reacting liquid jet problem, a diffusion flame supported by a one-step chemical reaction within the gaseous boundary layer is solved along the ellipse surface in subsonic crossflow. Typical flame structures and concentration profiles have been calculated for various locations along the jet cross-section as a function of upstream Mach numbers. The integrated reaction rate along the jet cross-section is used to predict ignition position, which is found to be situated near the stagnation point. While a multi-step reaction is needed to represent the ignition process more accurately, the present calculation does yield reasonable predictions concerning ignition along a curved surface.

Li, H.

1990-01-01T23:59:59.000Z

432

Transverse liquid fuel jet breakup, burning, and ignition  

SciTech Connect (OSTI)

An analytical/numerical study of the breakup, burning, and ignition of liquid fuels injected transversely into a hot air stream is conducted. The non-reacting liquid jet breakup location is determined by the local sonic point criterion first proposed by Schetz, et al. (1980). Two models, one employing analysis of an elliptical jet cross-section and the other employing a two-dimensional blunt body to represent the transverse jet, have been used for sonic point calculations. An auxiliary criterion based on surface tension stability is used as a separate means of determining the breakup location. For the reacting liquid jet problem, a diffusion flame supported by a one-step chemical reaction within the gaseous boundary layer is solved along the ellipse surface in subsonic crossflow. Typical flame structures and concentration profiles have been calculated for various locations along the jet cross-section as a function of upstream Mach numbers. The integrated reaction rate along the jet cross-section is used to predict ignition position, which is found to be situated near the stagnation point. While a multi-step reaction is needed to represent the ignition process more accurately, the present calculation does yield reasonable predictions concerning ignition along a curved surface.

Li, H.

1990-12-31T23:59:59.000Z

433

Ignition of HMX (cyclotetramethylenetetranitramine) using low energy laser diodes  

SciTech Connect (OSTI)

The sensitivity of blends of cyclotetramethylenetetranitramine (HMX) with carbon black and graphite to laser diode ignition was investigated. Using a 100-{mu}m optical fiber, a blend of 15,700 cm{sup 2}/g HMX with 3{percent} carbon black by weight was the most sensitive material tested, with a threshold of 72 mW. Pure, or undoped, HMX could not be ignited using 10 ms laser diode pulses with power levels up to 880 mW. In general, the HMX/carbon black blends were more sensitive than the HMX/graphite blends. HMX specific surface area also had a significant effect on sensitivity. Doubling the spot size increased the ignition threshold by a factor of approximately 2.7. Increasing the pulse width from 10 to 100 ms did not significantly reduce the laser diode power required for ignition. Photoacoustic spectrometer was used to compare the absorption characteristics of the HMX blends. The absorption spectra obtained correlated well with the sensitivity test data. 11 refs., 5 figs., 3 tabs.

Ewick, D.W.; Beckman, T.M.; Holy, J.A.; Thorpe, R.

1990-01-01T23:59:59.000Z

434

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

435

A study of in-cylinder combustion processes by using high speed multi-spectral infrared imaging and a robust statistical analysis method.  

E-Print Network [OSTI]

??Combustion processes in a spark-ignition engine were studied by using a high speed multi-spectral infrared camera system and a new robust statistical analysis method. Among… (more)

VanderVeer, Joseph R.

2008-01-01T23:59:59.000Z

436

Ignition characteristics of laser-ablated aluminum at shock pressures up to 2?GPa  

SciTech Connect (OSTI)

The ignition of aluminum particles under high pressure and temperature conditions is considered. The laser ablation method is used to generate oxide-free aluminum particles exposed to pressures ranging between 0.35 and 2.2?GPa. A continuous wave CO{sub 2} laser radiation heats the surface of the aluminum target until ignition is observed. We confirm ignition by a spectroscopic analysis of AlO vibronic band of 484?nm wavelength, and the radiant temperature is measured with respect to various pressures for estimating the heating energy for ignition. The ignition characteristics of the oxide-free aluminum particles exposed to extremely high pressures are reported.

Lee, Kyung-Cheol; Young Lee, Jae; Yoh, Jack J., E-mail: jjyoh@snu.ac.kr [Department of Mechanical and Aerospace Engineering, Seoul National University, 1 Gwanakro, Gwanakgu, Seoul 151-742 (Korea, Republic of); Taira, Tsubasa [Division of Applied Physics, Hokkaido University, Sapporo (Japan); Mo Koo, Goon [Department of Aerospace Engineering, University of Maryland, College Park, Maryland 20742 (United States)

2014-01-07T23:59:59.000Z

437

Investigation of the energy dependence of breakdown properties with a DC spark setup  

E-Print Network [OSTI]

The Compact LInear Collider (CLIC) study is a site independent feasibility study aiming at the development of a realistic technology at an affordable cost for a future linear electron-positron collider. The European Organization for Nuclear Research (CERN) is one of the collaborators for the CLIC study.The CLIC Test Facility (CTF3) positioned at CERN provides testing of this technology, including the testing of the proposed radio-frequency (RF) structures in a two-beam concept to produce the necessary accelerating electric field as high as 100 MV/m to reach the goal of a nominal total energy of 3 TeV. One problem at such high accelerating fields is electrical discharges, i.e. sparks, damaging the inside of the RF structures as well as deflecting the trajectories of accelerated particles. A Direct Current (DC) spark test setup is in use at CERN to aid the understanding of electrical discharges under vacuum conditions, also called vacuum arcs. In contrast to the more complex CTF3 setup, the DC spark setup is si...

Hansen, Anita; Calatroni, S

2009-01-01T23:59:59.000Z

438

Automobile Electrical Systems  

Science Journals Connector (OSTI)

The modern electrical system has been developed, over a period of some fifty years from the days of the early motor-car which usually had only one electrical system, namely, that of the ignition comp...

Arthur W. Judge

1970-01-01T23:59:59.000Z

439

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

SciTech Connect (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

440

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

SciTech Connect (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

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.


441

Target area and diagnostic interface issues on the National Ignition Facility (invited)  

SciTech Connect (OSTI)

The National Ignition Facility (NIF) is under construction at Lawrence Livermore National Laboratory for the DOE Stockpile Stewardship Program. It will be used for experiments for inertial confinement fusion ignition, high energy density science, and basic science. Many interface issues confront the experimentalist who wishes to design, fabricate, and install diagnostics, and to help this process, a set of standards and guideline documents is being prepared. Compliance with these will be part of a formal diagnostic design review process. In this article we provide a short description of each, with reference to more complete documentation. The complete documentation will also be available through the NIF Diagnostics web page. Target area interface issues are grouped into three categories. First are the layout and utility interface issues which include the safety analysis report, target area facility layout; target chamber port locations; diagnostic interferences and envelopes; utilities and cable tray distribution; and timing and fiducial systems. Second are the environment interface issues which include radiation electromagnetic interference/electromagnetic pulse effects and mitigation; electrical grounding, shielding, and isolation; and cleanliness and vacuum guidelines. Third are the operational interface issues which include manipulator based target diagnostics, diagnostic alignment, shot life cycle and setup, diagnostic controllers; integrated computer control system; shot data archival; classified operations; and remote operations.

Bell, Perry; Lee, Dean; Wootton, Alan; Mascio, Bill; Kimbrough, Joe; Sewall, Noel; Hibbard, Wilthea; Dohoney, Pat; Landon, Mark; Christianson, George (and others) [and others

2001-01-01T23:59:59.000Z

442

Performance and Emissions of a Compression Ignition Engine Fueled with Diesel/Oxygenate Blends for Various Fuel Delivery Advance Angles  

Science Journals Connector (OSTI)

State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, Xi'an, People's Republic of China ... In the application of pure oxygenated fuels, Fleisch et al.,1 Kapus and Ofner,2 and Sorenson and Mikkelsen3 have studied dimethyl ether (DME) in a modified diesel engine, and their results showed that the engine could achieve ultralow-emission prospects without a fundamental change in combustion systems. ... Although some previous work has revealed the characteristics of diesel/ethanol blends in a compression ignition engine (Satge de Caro et al.,14 Ali et al.15), there, however, is still much work that needs to be done in regard to the application of diesel/methanol blends in compression ignition engines, especially in clarifying the basic combustion and emission. ...

Zuohua Huang; Hongbing Lu; Deming Jiang; Ke Zeng; Bing Liu; Junqiang Zhang; Xibin Wang

2005-02-02T23:59:59.000Z

443

Observation of strong electromagnetic fields around laser-entrance holes of ignition-scale hohlraums in inertial-confinement fusion experiments at the National Ignition Facility  

E-Print Network [OSTI]

Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA 02139 USA 2 Lawrence Livermore National Laboratory, Livermore, CA 94550 USA 3 Los Alamos National Laboratory, Los Alamos, NM) experiments utilizing ignition-scaled hohlraums at the National Ignition Facility (NIF). A striking

444

Optimal conditions for shock ignition of scaled cryogenic deuterium-tritium targets  

SciTech Connect (OSTI)

Within the framework of the shock-ignition (SI) scheme, ignition conditions are reached following the separation of the compression and heating phases. First, the shell is compressed at a sub-ignition implosion velocity; then an intense laser spike is launched at the end of the main drive, leading to the propagation of a strong shock through the precompressed fuel. The minimal laser energy required for ignition of scaled deuterium-tritium (DT) targets is assessed by calculations. A semi-empiric model describing the ignitor shock generation and propagation in the fuel assembly is defined. The minimal power needed in the laser spike pulse to achieve ignition is derived from the hydrodynamic model. Optimal conditions for ignition of scaled targets are explored in terms of laser intensity, shell-implosion velocity, and target scale range for the SI process. Curves of minimal laser requirements for ignition are plotted in the energy-power diagram. The most economic and reliable conditions for ignition of a millimeter DT target are observed in the 240- to 320-km/s implosion velocity range and for the peak laser intensity ranging from {approx}2 Multiplication-Sign 10{sup 15} W/cm{sup 2} up to 5 Multiplication-Sign 10{sup 15} W/cm{sup 2}. These optimal conditions correspond to shock-ignited targets for a laser energy of {approx}250 kJ and a laser power of 100 to 200 TW. Large, self-ignited targets are particularly attractive by offering ignition at a lower implosion velocity and a reduced laser intensity than for conventional ignition. The SI scheme allows for the compression and heating phases of the high power laser energy research facility target to be performed at a peak laser intensity below 10{sup 16} W/cm{sup 2}. A better control of parametric and hydrodynamic instabilities within the SI scheme sets it as an optimal and reliable approach to attain ignition of large targets.

Lafon, M. [Laboratory for Laser Energetics and Fusion Science Center, University of Rochester, Rochester, New York 14623 (United States); University of Bordeaux-CNRS-CEA, Centre Lasers Intenses et Applications, UMR 5107, 33405 Talence (France); Ribeyre, X.; Schurtz, G. [University of Bordeaux-CNRS-CEA, Centre Lasers Intenses et Applications, UMR 5107, 33405 Talence (France)

2013-02-15T23:59:59.000Z

445

Laser design basis for the National Ignition Facility  

SciTech Connect (OSTI)

Controlled nuclear fusion initiated by highly intense laser beams has been the subject of experiment for many years. The National Ignition Facility (NIF) represents the culmination of design efforts to provide a laser facility that will successfully demonstrate fusion ignition in the laboratory. In this so-called inertial confinement approach, energetic driver beams (laser, X-ray, or charged particle) heat the outer surface of a spherical capsule containing deuterium and tritium (DT) fuel. As the capsule surface explosively evaporates, reaction pressure compresses the DT fuel causing the central core of the fuel to reach extreme density and temperature. When the central temperature is high enough, DT fusion reactions occur. The energy released from these reactions further heats the compressed fuel, and fusion burn propagates outward through the colder regions of the capsule much more rapidly than the inertially confined capsule can expand. The resulting fusion reactions yield many times more energy than was absorbed from the driver beams.

Hunt, J.T.; Manes, K.R.; Murray, J.R.; Renard, P.A.; Sawicki, R.; Trenholme, J.B.; Williams, W.

1994-06-01T23:59:59.000Z

446

Hydrodynamic instabilities in beryllium targets for the National Ignition Facility  

SciTech Connect (OSTI)

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

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

2014-09-15T23:59:59.000Z

447

Fast ignition driven by quasi-monoenergetic ions: Optimal ion type and reduction of ignition energies with an ion beam array  

E-Print Network [OSTI]

Fast ignition of inertial fusion targets driven by quasi-monoenergetic ion beams is investigated by means of numerical simulations. Light and intermediate ions such as lithium, carbon, aluminium and vanadium have been considered. Simulations show that the minimum ignition energies of an ideal configuration of compressed Deuterium-Tritium are almost independent on the ion atomic number. However, they are obtained for increasing ion energies, which scale, approximately, as Z^2, where Z is the ion atomic number. Assuming that the ion beam can be focused into 10 {\\mu}m spots, a new irradiation scheme is proposed to reduce the ignition energies. The combination of intermediate Z ions, such as 5.5 GeV vanadium, and the new irradiation scheme allows a reduction of the number of ions required for ignition by, roughly, three orders of magnitude when compared with the standard proton fast ignition scheme.

Honrubia, J J; Hegelich, B M; Murakami, M; Enriquez, C D

2014-01-01T23:59:59.000Z

448

Fabrication of Tungsten-Rhenium Cladding materials via Spark Plasma Sintering for Ultra High Temperature Reactor Applications  

SciTech Connect (OSTI)

This research will develop an optimized, cost-effective method for producing high-purity tungsten-rhenium alloyed fuel clad forms that are crucial for the development of a very high-temperature nuclear reactor. The study will provide critical insight into the fundamental behavior (processing-microstructure- property correlations) of W-Re alloys made using this new fabrication process comprising high-energy ball milling (HEBM) and spark plasma sintering (SPS). A broader goal is to re-establish the U.S. lead in the research field of refractory alloys, such as W-Re systems, with potential applications in very high-temperature nuclear reactors. An essential long-term goal for nuclear power is to develop the capability of operating nuclear reactors at temperatures in excess of 1,000K. This capability has applications in space exploration and some special terrestrial uses where high temperatures are needed in certain chemical or reforming processes. Refractory alloys have been identified as being capable of withstanding temperatures in excess of 1,000K and are considered critical for the development of ultra hightemperature reactors. Tungsten alloys are known to possess extraordinary properties, such as excellent high-temperature capability, including the ability to resist leakage of fissile materials when used as a fuel clad. However, there are difficulties with the development of refractory alloys: 1) lack of basic experimental data on thermodynamics and mechanical and physical properties, and 2) challenges associated with processing these alloys.

Indrajit Charit; Darryl Butt; Megan Frary; Mark Carroll

2012-11-05T23:59:59.000Z

449

High load operation in a homogeneous charge compression ignition engine  

DOE Patents [OSTI]

A homogeneous charge compression ignition engine is set up by first identifying combinations of compression ratio and exhaust gas percentages for each speed and load across the engines operating range. These identified ratios and exhaust gas percentages can then be converted into geometric compression ratio controller settings and exhaust gas recirculation rate controller settings that are mapped against speed and load, and made available to the electronic

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

2008-12-23T23:59:59.000Z

450

Gasoline Engine Economy as Affected by the Time of Ignition  

E-Print Network [OSTI]

KU ScholarWorks | The University of Kansas Pre-1923 Dissertations and Theses Collection Gasoline Engine Economy as Affected by the Time of Ignition 1907 by George Jay Hopkins This work was digitized by the Scholarly Communications program staff... in the KU Libraries’ Center for Digital Scholarship. http://kuscholarworks.ku.edu Submitted to the University of Kansas in partial fulfillment of the requirements for the Degree of Bachelor of Science GASOLINE ENCUNE ECONOMY as Affected W the Time...

Hopkins, George Jay

1907-01-01T23:59:59.000Z

451

High Efficiency GDI Engine Research, with Emphasis on Ignition Systems  

Broader source: Energy.gov [DOE]

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

452

Laser ignition of nickel-aluminum powder systems  

Science Journals Connector (OSTI)

A method for determining the thermokinetic constants of the SHS reaction and thermophysical properties of the initial mixture and reaction products involving the use of laser initiation of the reactive mixture ha...

M. I. Shilyaev; V. É. Borzykh; A. R. Dorokhov

453

Optomechanical considerations for the VISAR diagnostic at the National Ignition Facility (NIF)  

SciTech Connect (OSTI)

The National Ignition Facility (NIF) requires optical diagnostics for measuring shock velocities in shock physics experiments. The velocity interferometer for any reflector measures shock velocities at a location remote to the NIF target chamber. Our team designed two systems, one for a polar port orientation, and the other to accommodate two equatorial ports. The polar-oriented design requires a 48-m optical relay to move the light from inside the target chamber to a separately housed measurement and laser illumination station. The currently operational equatorial design requires a much shorter relay of 21 m. Both designs posed significant optomechanical challenges due to the long optical path length, large quantity of optical elements, and stringent NIF requirements. System design had to tightly control the use of lubricants and materials, especially those inside the vacuum chamber; tolerate earthquakes and radiation; and consider numerous other tolerance, alignment, and steering adjustment issues. To ensure compliance with NIF performance requirements, we conducted a finite element analysis.

Kaufman, Morris I.; Celeste, John R.; Frogget, Brent C.; Lee, Tony L.; GacGowan, Brian J.; Malone, Robert M.; Ng, Edmund W.; Tunnell, Tom W.; Watts, Phillip W.

2006-09-01T23:59:59.000Z

454

Investigation of proton focusing and conversion efficiency for proton fast ignition  

E-Print Network [OSTI]

After ignition, a thermonuclear burn wave spreads radiallythe shell to create the thermonuclear burn wave. At 10 keV,heating the plasma to thermonuclear temperatures. Protons

Bartal, Teresa Jean

2012-01-01T23:59:59.000Z

455

Effect of ambient conditions and fuel properties on homogeneous charge compression ignition engine operation  

E-Print Network [OSTI]

Practical application of Homogeneous Charge Compression Ignition (HCCI) combustion must demonstrate robust responses to variations in environmental conditions. This work examines the impact of ambient conditions and fuel ...

Andreae, Morgan M. (Morgan MacKenzie)

2006-01-01T23:59:59.000Z

456

IGNITION TRANSIENT IN AN ETHYLENE FUELED SCRAMJET ENGINE WITH AIR THROTTLING.  

E-Print Network [OSTI]

??This research focuses on the modeling and simulation of ignition transient and subsequent combustion dynamics in an ethylene fueled supersonic combustion ramjet (scramjet) engine. The… (more)

Li, Jian

2009-01-01T23:59:59.000Z

457

A Home Ignition Assessment Model Applied to Structures in the Wildland-Urban Interface  

SciTech Connect (OSTI)

The issue of exterior fire threat to buildings, from either wildfires in the wildland-urban interface or neighboring structure fires, is critically important. To address this, theWildfire Ignition Resistant Home Design (WIRHD) program was initiated. The WIRHD program developed a tool, theWildFIREWizard, that will allow homeowners to estimate the external fire threat to their homes based on specific features and characteristics of the homes and yards. The software then makes recommendations to reduce the threat. The inputs include the structural and material features of the home and information about any ignition sources or flammable objects in its immediate vicinity, known as the home ignition zone. The tool comprises an ignition assessment model that performs explicit calculations of the radiant and convective heating of the building envelope from the potential ignition sources. This article describes a series of material ignition and flammability tests that were performed to calibrate and/or validate the ignition assessment model. The tests involved exposing test walls with different external siding types to radiant heating and/or direct flame contact.The responses of the test walls were used to determine the conditions leading to melting, ignition, or any other mode of failure of the walls. Temperature data were used to verify the model predictions of temperature rises and ignition times of the test walls.

Biswas, Kaushik [ORNL; Werth, David [Savannah River National Laboratory, Aiken, SC; Gupta, Narendra [Savannah River National Laboratory, Aiken, SC

2013-01-01T23:59:59.000Z

458

Laser ignition of a cryogenic thruster using a miniaturised Nd:YAG laser  

Science Journals Connector (OSTI)

An experimental study has been conducted to assess the feasibility of implementing laser ignition in cryogenic reaction and control and orbital manouvering thrusters. A experimental...

Manfletti, Chiara; Kroupa, Gerhard

2013-01-01T23:59:59.000Z

459

IGNITION PROCESSES AND FLAME SPREADING IN A GRANULAR SOLID PROPELLANT BED.  

E-Print Network [OSTI]

??Understanding the detailed ignition, flame spreading, and combustion processes inside of a granular solid propellant bed is vital for accurate internal ballistic modeling and development… (more)

Colletti, Alexander

2010-01-01T23:59:59.000Z

460

Utilizing the Rapid Ignition Region of HCCI to Attain > 60% BTE...  

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

that is far from constant volume as it continues over many CAD. Is there an ICRE architecture suitable to HCCI rapid ignition and capable of supporting constant volume...

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they are not comprehensive nor are they the most current set.
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to obtain the most current and comprehensive results.


461

Modeling the Number of Ignitions Following an Earthquake: Developing Prediction Limits for Overdispersed Count Data  

Broader source: Energy.gov [DOE]

Modeling the Number of Ignitions Following an Earthquake: Developing Prediction Limits for Overdispersed Count Data Elizabeth J. Kelly and Raymond N. Tell

462

Indirect-Drive Noncryogenic Double-Shell Ignition Targets for the National Ignition Facility: Design and Analysis  

SciTech Connect (OSTI)

The central goal of the National Ignition Facility (NIF) is demonstration of controlled thermonuclear ignition. The mainline ignition target is a low-Z, single-shell cryogenic capsule designed to have weakly nonlinear Rayleigh-Taylor growth of surface perturbations. Double-shell targets are an alternative design concept that avoids the complexity of cryogenic preparation but has greater physics uncertainties associated with performance-degrading mix. A typical double-shell design involves a high-Z inner capsule filled with DT gas and supported within a low-Z ablator shell. The largest source of uncertainty for this target is the degree of highly evolved nonlinear mix on the inner surface of the high-Z shell. High Atwood numbers and feed-through of strong outer surface perturbation growth to the inner surface promote high levels of instability. The main challenge of the double-shell target designs is controlling the resulting nonlinear mix to levels that allow ignition to occur. Design and analysis of a suite of indirect-drive NIF double-shell targets with hohlraum temperatures of 200 eV and 250 eV are presented. Analysis of these targets includes assessment of two-dimensional radiation asymmetry as well as nonlinear mix. Two-dimensional integrated hohlraum simulations indicate that the x-ray illumination can be adjusted to provide adequate symmetry control in hohlraums specially designed to have high laser-coupling efficiency [Suter et al., Phys. Plasmas 5, 2092 (2000)]. These simulations also reveal the need to diagnose and control localized 10-15 keV x-ray emission from the high-Z hohlraum wall because of strong absorption by the high-Z inner shell. Preliminary estimates of the degree of laser backscatter from an assortment of laser-plasma interactions suggest comparatively benign hohlraum conditions. Application of a variety of nonlinear mix models and phenomenological tools, including buoyancy-drag models, multimode simulations and fall-line optimization, indicates a possibility of achieving ignition, i.e., fusion yields greater than 1 MJ. Planned experiments on the Omega laser to test current understanding of high-energy radiation flux asymmetry and mix-induced yield degradation in double-shell targets are described.

Amendt, P.; Colvin, J.; Tipton, R.E.; Hinkel, D.; Edwards, J.J.; Landen, O.I.; Ramshaw, J.D.; Suter, L.J.; Watt, W.G.

2001-10-15T23:59:59.000Z

463

Laser Ignition of Explosive Compositions Based on di-(3-hydrazino-4-amino-1,2,3-triazole)-Copper(II) Perchlorate  

Science Journals Connector (OSTI)

Laser ignition of explosives based on di-(3-hydrazino ... radiation spot diameter and time dependences of the ignition delay were constructed. An ignition mechanism is proposed that is based on...

A. V. Chernai; V. V. Sobolev; V. A. Chernai…

2003-05-01T23:59:59.000Z

464

PROPERTIES OF CP: COEFFICIENT OF THERMAL EXPANSION, DECOMPOSITION KINETICS, AND REACTION TO SPARK, FRICTION AND IMPACT  

SciTech Connect (OSTI)

The properties of pentaamine (5-cyano-2H-tetrazolato-N2) cobalt (III) perchlorate (CP), which was first synthesized in 1968, continues to be of interest for predicting behavior in handling, shipping, aging, and thermal cook-off situations. We report coefficient of thermal expansion (CTE) values over four specific temperature ranges, decomposition kinetics using linear and isothermal heating, and the reaction to three different types of stimuli: impact, spark, and friction. The CTE was measured using a Thermal Mechanical Analyzer (TMA) for samples that were uniaxially compressed at 10,000 psi and analyzed over a dynamic temperature range of -20 C to 70 C. Differential scanning calorimetry, DSC, was used to monitor CP decomposition at linear heating rates of 1-7 C min{sup -1} in perforated pans and of 0.1-1.0 C min{sup -1} in sealed pans. The kinetic triplet was calculated using the LLNL code Kinetics05, and predictions for 210 and 240 C are compared to isothermal thermogravimetric analysis (TGA) experiments. Values are also reported for spark, friction, and impact sensitivity.

Weese, R K; Burnham, A K

2005-09-28T23:59:59.000Z

465

Implosion dynamics measurements at the National Ignition Facility  

SciTech Connect (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

466

Overview of the gamma reaction history diagnostic for the national ignition facility (NIF)  

SciTech Connect (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 900 off-axis parabolic mirrors to rel ay Cherenkov light from a volume of pressurized gas. This non imaging optical system has the high-speed detector placed at a stop position with the Cherenkov light delayed until after the prompt gammas have passed through the detector. Because of the wavelength range (250 to 700 nm), the optical element surface finish was a key design constraint. A cluster of four channels (each set to a different gas pressure) will collect the time histories for different energy ranges of gammas.

Kim, Yong Ho [Los Alamos National Laboratory; Evans, Scott C [Los Alamos National Laboratory; Herrmann, Hans W [Los Alamos National Laboratory; Mack, Joseph M [Los Alamos National Laboratory; Young, Carl S [Los Alamos National Laboratory; Malone, Robert M [Los Alamos National Laboratory; Cox, Brian C [Los Alamos National Laboratory; Frogget, Brent C [Los Alamos National Laboratory; Kaufman, Morris I [Los Alamos National Laboratory; Tunnell, Thomas W [Los Alamos National Laboratory; Tibbitts, Aric [Los Alamos National Laboratory; Palagi, Martin J [NST/LAS VEGAS; Stoeffl, Wolfgang [LLNL

2010-01-01T23:59:59.000Z

467

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

SciTech Connect (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 90ş 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

468

Contribution of different mechanisms of energy transfer in the development of the thermonuclear combustion wave upon fast ignition of ICF-targets  

Science Journals Connector (OSTI)

Temporal characteristics of the thermonuclear combustion wave, critical parameters of the igniter ... fast ignition of the spherically symmetric inertial confinement fusion (ICF) target of the reactor type ... co...

N. B. Gubinskaya; S. Yu. Gus’kov; D. V. Il’in…

2008-01-01T23:59:59.000Z

469

The Role of Viscosity in TATB Hot Spot Ignition  

SciTech Connect (OSTI)

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

470

A sensitive neutron spectrometer for the National Ignition Facility  

SciTech Connect (OSTI)

We are developing a sensitive neutron spectrometer for the National Ignition Facility laser at Livermore. The spectrometer will consist of a 1020 channel single-neutron-interaction time-of-flight detector array fielded 23 m from the neutron-producing target. It will use an existing detector array together with upgraded electronics for improved time resolution. Measurements of neutron yield, ion and electron temperatures, and density-radius product are all possible under certain conditions using one-, two-, or three-step reaction processes. The locations of the most important potential sources of scattered neutron backgrounds are determined as the first step in designing collimation to reduce these backgrounds.

Watt, R. G.; Chrien, R. E.; Klare, K. A.; Murphy, T. J.; Wilson, D. C.; Haan, S.

2001-01-01T23:59:59.000Z

471

TIBER: Tokamak Ignition/Burn Experimental Research. Final design report  

SciTech Connect (OSTI)

The Tokamak Ignition/Burn Experimental Research (TIBER) device is the smallest superconductivity tokamak designed to date. In the design plasma shaping is used to achieve a high plasma beta. Neutron shielding is minimized to achieve the desired small device size, but the superconducting magnets must be shielded sufficiently to reduce the neutron heat load and the ga