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1

Engines - Spark Ignition Engines - Direct Injection - Omnivorous Engine  

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

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

2

Direct Injection Compression Ignition Diesel Automotive Technology Education GATE Program  

SciTech Connect

The underlying goal of this prqject was to provide multi-disciplinary engineering training for graduate students in the area of internal combustion engines, specifically in direct injection compression ignition engines. The program was designed to educate highly qualified engineers and scientists that will seek to overcome teclmological barriers preventing the development and production of cost-effective high-efficiency vehicles for the U.S. market. Fu1iher, these highly qualified engineers and scientists will foster an educational process to train a future workforce of automotive engineering professionals who are knowledgeable about and have experience in developing and commercializing critical advanced automotive teclmologies. Eight objectives were defmed to accomplish this goal: 1. Develop an interdisciplinary internal co1nbustion engine curriculum emphasizing direct injected combustion ignited diesel engines. 2. Encourage and promote interdisciplinary interaction of the faculty. 3. Offer a Ph.D. degree in internal combustion engines based upon an interdisciplinary cuniculum. 4. Promote strong interaction with indusuy, develop a sense of responsibility with industry and pursue a self sustaining program. 5. Establish collaborative arrangements and network universities active in internal combustion engine study. 6. Further Enhance a First Class educational facility. 7. Establish 'off-campus' M.S. and Ph.D. engine programs of study at various indusuial sites. 8. Extend and Enhance the Graduate Experience.

Carl L. Anderson

2006-09-25T23:59:59.000Z

3

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

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

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

4

FY2002 Progress Report for Fuels for Advanced Compression Ignition Direct Injection (CIDI) Engines  

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

Fuels for Advanced Compression Fuels for Advanced Compression Ignition Direct Injection (CIDI) Engines Energy Efficiency and Renewable Energy Office of FreedomCAR and Vehicle Technologies Approved by Stephen Goguen November 2002 Fuels for Advanced CIDI Engines FY 2002 Progress Report iii CONTENTS CONTENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii INDEX OF PRIMARY CONTACTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v I. INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 II. FUEL/LUBRICANT EFFECTS TESTING ON ENGINE PERFORMANCE . . . . . . . . . 13 A. Oil Consumption Contribution to CIDI PM Emissions during Transient Operation . . . . . . . . . . . . . . . . . . . .13

5

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

6

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

7

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

8

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

9

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...

10

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

SciTech Connect

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

11

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

12

Analysis of ignition behavior in a turbocharged direct injection dual fuel engine using propane and methane as primary fuels  

SciTech Connect

This paper presents experimental analyses of the ignition delay (ID) behavior for diesel-ignited propane and diesel-ignited methane dual fuel combustion. Two sets of experiments were performed at a constant speed (1800 rev/min) using a 4-cylinder direct injection diesel engine with the stock ECU and a wastegated turbocharger. First, the effects of fuel-air equivalence ratios (���© pilot �¢���¼ 0.2-0.6 and ���© overall �¢���¼ 0.2-0.9) on IDs were quantified. Second, the effects of gaseous fuel percent energy substitution (PES) and brake mean effective pressure (BMEP) (from 2.5 to 10 bar) on IDs were investigated. With constant ���© pilot (> 0.5), increasing ���© overall with propane initially decreased ID but eventually led to premature propane autoignition; however, the corresponding effects with methane were relatively minor. Cyclic variations in the start of combustion (SOC) increased with increasing ���© overall (at constant ���© pilot), more significantly for propane than for methane. With increasing PES at constant BMEP, the ID showed a nonlinear (initially increasing and later decreasing) trend at low BMEPs for propane but a linearly decreasing trend at high BMEPs. For methane, increasing PES only increased IDs at all BMEPs. At low BMEPs, increasing PES led to significantly higher cyclic SOC variations and SOC advancement for both propane and methane. Finally, the engine ignition delay (EID) was also shown to be a useful metric to understand the influence of ID on dual fuel combustion.

Polk, A. C.; Gibson, C. M.; Shoemaker, N. T.; Srinivasan, K. K.; Krishnan, S. R.

2011-10-05T23:59:59.000Z

13

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

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

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

14

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

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

15

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

16

Combustion Characteristics of Diesohol Using Biodiesel as an Additive in a Direct Injection Compression Ignition Engine under Various Compression Ratios  

Science Journals Connector (OSTI)

Studies on combustion characteristics are essential for the optimization of engine design with the use of alternative fuels as compression ignition (CI) engines are basically designed to operate with neat diesel. ... Fleisch et al.,(6) Kapus and Ofner,(7) and Sorenson and Mikkelsen(8) have studied the utilization of pure oxygenated fuels in diesel engines and found that they can achieve ultralow emissions without a fundamental change in the combustion system. ... Engines Research Laboratory in the Mechanical Engineering Department with modern computerized experimental facilities to the international standards. ...

V. Arul Mozhi Selvan; R. B. Anand; M. Udayakumar

2009-10-05T23:59:59.000Z

17

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

SciTech Connect

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

18

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

19

Investigations on emission characteristics of the pongamia biodiesel–diesel blend fuelled twin cylinder compression ignition direct injection engine using exhaust gas recirculation methodology and dimethyl carbonate as additive  

Science Journals Connector (OSTI)

Experiments were carried out on a twin cylinder direct injection compression ignition engine using pongamia biodiesel–diesel blend as fuel with exhaust gas recirculation (EGR) and dimethyl carbonate (DMC) as additive. The experimental results showed that pongamia biodiesel–diesel blend fuelled engine with EGR and DMC can simultaneously reduce smoke and nitric oxide ( NO x ) emission. The NO x emission was reduced by about 17.68% for 10% of EGR introduction and about 13.55% increase in smoke emission. When dimethyl carbonate was added with EGR the engine emits lower smoke with lesser NO x emission and it showed that the smoke reduction rate had a linear relationship with DMC percentage. The carbon monoxide (CO) and hydrocarbon (HC) emissions also decreased when DMC was added. However the addition of DMC with EGR caused an increase in both BSEC and BTE.

M. Pandian; S. P. Sivapirakasam; M. Udayakumar

2010-01-01T23:59:59.000Z

20

Direct tuyere injection of oxygen for enhanced coal combustion  

SciTech Connect

Injecting oxygen directly into the tuyere blowpipe can enhance the ignition and combustion of injected pulverized coal, allowing the efficient use of higher coal rates at high furnace production levels. The effects of direct oxygen injection have been estimated from an analysis of the factors controlling the dispersion, heating, ignition, and combustion of injected coal. Injecting ambient temperature oxygen offers mechanical improvements in the dispersion of coal but provides little thermochemical benefit over increased blast enrichment. Injecting hot oxygen through a novel, patented thermal nozzle lance offers both mechanical and thermochemical benefits over increased enrichment or ambient oxygen injection. Plans for pilot-scale and commercial-scale testing of this new lance are described.

Riley, M.F. [Praxair, Inc., Tarrytown, NY (United States)

1996-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "ignition direct injection" 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

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

NLE Websites -- All DOE Office Websites (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...

22

Premixed direct injection disk  

DOE Patents (OSTI)

A fuel/air mixing disk for use in a fuel/air mixing combustor assembly is provided. The disk includes a first face, a second face, and at least one fuel plenum disposed therebetween. A plurality of fuel/air mixing tubes extend through the pre-mixing disk, each mixing tube including an outer tube wall extending axially along a tube axis and in fluid communication with the at least one fuel plenum. At least a portion of the plurality of fuel/air mixing tubes further includes at least one fuel injection hole have a fuel injection hole diameter extending through said outer tube wall, the fuel injection hole having an injection angle relative to the tube axis. The invention provides good fuel air mixing with low combustion generated NOx and low flow pressure loss translating to a high gas turbine efficiency, that is durable, and resistant to flame holding and flash back.

York, William David; Ziminsky, Willy Steve; Johnson, Thomas Edward; Lacy, Benjamin; Zuo, Baifang; Uhm, Jong Ho

2013-04-23T23:59:59.000Z

23

Premixed direct injection nozzle  

DOE Patents (OSTI)

An injection nozzle having a main body portion with an outer peripheral wall is disclosed. The nozzle includes a plurality of fuel/air mixing tubes disposed within the main body portion and a fuel flow passage fluidly connected to the plurality of fuel/air mixing tubes. Fuel and air are partially premixed inside the plurality of the tubes. A second body portion, having an outer peripheral wall extending between a first end and an opposite second end, is connected to the main body portion. The partially premixed fuel and air mixture from the first body portion gets further mixed inside the second body portion. The second body portion converges from the first end toward said second end. The second body portion also includes cooling passages that extend along all the walls around the second body to provide thermal damage resistance for occasional flame flash back into the second body.

Zuo, Baifang (Simpsonville, SC); Johnson, Thomas Edward (Greer, SC); Lacy, Benjamin Paul (Greer, SC); Ziminsky, Willy Steve (Simpsonville, SC)

2011-02-15T23:59:59.000Z

24

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

25

Staged direct injection diesel engine  

DOE Patents (OSTI)

A diesel engine having staged injection for using lower cetane number fuels than No. 2 diesel fuel. The engine includes a main fuel injector and a pilot fuel injector. Pilot and main fuel may be the same fuel. The pilot injector injects from five to fifteen percent of the total fuel at timings from 20.degree. to 180.degree. BTDC depending upon the quantity of pilot fuel injected, the fuel cetane number and speed and load. The pilot fuel injector is directed toward the centerline of the diesel cylinder and at an angle toward the top of the piston, avoiding the walls of the cylinder. Stratification of the early injected pilot fuel is needed to reduce the fuel-air mixing rate, prevent loss of pilot fuel to quench zones, and keep the fuel-air mixture from becoming too fuel lean to become effective. In one embodiment, the pilot fuel injector includes a single hole for injection of the fuel and is directed at approximately 48.degree. below the head of the cylinder.

Baker, Quentin A. (San Antonio, TX)

1985-01-01T23:59:59.000Z

26

carbon sequestration via direct injection  

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

SEQUESTRATION VIA DIRECT INJECTION SEQUESTRATION VIA DIRECT INJECTION Howard J. Herzog, Ken Caldeira, and Eric Adams INTRODUCTION The build-up of carbon dioxide (CO 2 ) and other greenhouse gases in the Earth's atmosphere has caused concern about possible global climate change. As a result, international negotiations have produced the Framework Convention on Climate Change (FCCC), completed during the 1992 Earth Summit in Rio de Janeiro. The treaty, which the United States has ratified, calls for the "stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system." The primary greenhouse gas is CO 2 , which is estimated to contribute to over two-thirds of any climate change. The primary source of CO

27

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

28

Advanced Gasoline Turbocharged Direct Injection (GTDI) Engine...  

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

in Gasoline Turbocharged Direct Injection (GTDI) engine technology in the near term as a cost effective, high volume, fuel economy solution, marketed globally as EcoBoost...

29

Exhaust Emissions and Combustion Characteristics of a Direct Injection (DI) Diesel Engine Fueled with Methanol?Diesel Fuel Blends at Different Injection Timings  

Science Journals Connector (OSTI)

Exhaust Emissions and Combustion Characteristics of a Direct Injection (DI) Diesel Engine Fueled with Methanol?Diesel Fuel Blends at Different Injection Timings ... Because of their fuel economy and high reliability, compression-ignition (CI) engines known as diesel engines have been penetrating a number of markets around the world. ...

Mustafa Canakci; Cenk Sayin; Metin Gumus

2008-09-27T23:59:59.000Z

30

Configuring the National Ignition Facility for direct-drive experiments  

SciTech Connect

The National Ignition Facility (NIF) is a project whose primary mission is to provide an above-ground experimental capability for maintaining nuclear competence and weapons effects simulation, and to pursue the achievement of fusion ignition utilizing solid state lasers as the energy driver. In this facility a large number of laser beams are focused onto a small target located at the center of a spherical target chamber. The laser energy is delivered in a few billionths of a second, raising the temperature and density of the nuclear materials in the target to levels where significant thermonuclear energy is released. The thermonuclear reaction proceeds very rapidly, so that the target materials remain confined by their own inertia during the thermonuclear reaction. This type of approach is called inertial confinement fusion (ICF). The proposed project is described in a conceptual design report (CDR) that was released in May 1994. Early in FY95, a collaboration between the University of Rochester and the Lawrence Livermore National Laboratory was established to study reconfiguring the NIF to accommodate direct-drive experiments. The present paper is a report to the scientific community, primarily the scientists and engineers working on the design of the NIF. It represents results from work in progress, specifically work completed by the end of the second quarter FY95. This report has two main sections. The first describes the target requirements on the laser drive, and the second part describes how the NIF laser can be configured to accommodate both indirect and direct drive. The report includes a description of the scientific basis for these conclusions. Though a complete picture does not exist, the present understanding is sufficient to conclude that the primary target requirements and laser functional requirements for indirect and direct drive are quite compatible. It is evidently straightforward to reconfigure the NIF to accommodate direct and indirect drive.

Eimerl, D. [ed.

1995-07-01T23:59:59.000Z

31

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

32

Investigation of Direct Injection Vehicle Particulate Matter...  

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

Emissions This study focuses primarily on particulate matter mass analysis of a gasoline direct injection engine in a test cell with a chassis dynamometer. p-10gibbs.pdf...

33

Hybrid combustion-premixed gasoline homogeneous charge ignited by injected diesel fuel-4-stroke cycle engines  

SciTech Connect

This paper describes the formation and testing of two hybrid combustion engines, wherein a premixed gasoline homogeneous charge was ignited by a small amount of injected diesel fuel under high compression ratio, by modifying open chamber and prechamber 4-stroke cycle diesel engines. It was found that the premixed gasoline was effective not only for decreasing the fuel consumption but also for reducing the smoke density both in the heavy and over-load regions. The effect of introducing a small amount N/sub 2/ gas for suppressing the diesel knock in the heavy load region also was examined.

Yonetani, H.; Okanishi, N.; Fukutani, I.; Watanabe, E.

1989-01-01T23:59:59.000Z

34

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

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

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...

35

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...

36

European Lean Gasoline Direct Injection Vehicle Benchmark  

SciTech Connect

Lean Gasoline Direct Injection (LGDI) combustion is a promising technical path for achieving significant improvements in fuel efficiency while meeting future emissions requirements. Though Stoichiometric Gasoline Direct Injection (SGDI) technology is commercially available in a few vehicles on the American market, LGDI vehicles are not, but can be found in Europe. Oak Ridge National Laboratory (ORNL) obtained a European BMW 1-series fitted with a 2.0l LGDI engine. The vehicle was instrumented and commissioned on a chassis dynamometer. The engine and after-treatment performance and emissions were characterized over US drive cycles (Federal Test Procedure (FTP), the Highway Fuel Economy Test (HFET), and US06 Supplemental Federal Test Procedure (US06)) and steady state mappings. The vehicle micro hybrid features (engine stop-start and intelligent alternator) were benchmarked as well during the course of that study. The data was analyzed to quantify the benefits and drawbacks of the lean gasoline direct injection and micro hybrid technologies from a fuel economy and emissions perspectives with respect to the US market. Additionally that data will be formatted to develop, substantiate, and exercise vehicle simulations with conventional and advanced powertrains.

Chambon, Paul H [ORNL] [ORNL; Huff, Shean P [ORNL] [ORNL; Edwards, Kevin Dean [ORNL] [ORNL; Norman, Kevin M [ORNL] [ORNL; Prikhodko, Vitaly Y [ORNL] [ORNL; Thomas, John F [ORNL] [ORNL

2011-01-01T23:59:59.000Z

37

Experimental Study of Diesel Fuel Effects on Direct Injection (DI) Diesel Engine Performance and Pollutant Emissions  

Science Journals Connector (OSTI)

Experimental Study of Diesel Fuel Effects on Direct Injection (DI) Diesel Engine Performance and Pollutant Emissions ... The test fuels indicate variable hydrocarbon composition and physical and chemical properties, and they were prepared under a European Union research program aiming to identify future fuel formulations for use in modern DI diesel engines. ... 1,2,4-9,13,14,16,17,24-26 In general, there is an interrelation between the molecular structure (paraffins, olefins, napthenes, and aromatic hydrocarbons), the chemical properties (cetane number, ignition point, etc.), and the physical properties (density, viscosity, surface tension, etc.) of the diesel fuel. ...

Theodoros C. Zannis; Dimitrios T. Hountalas; Roussos G. Papagiannakis

2007-07-19T23:59:59.000Z

38

Asymmetric directly driven capsule implosions: Modeling and experiments-A requirement for the National Ignition Facility  

SciTech Connect

Direct-drive experiments at the University of Rochester's OMEGA laser [T. R. Boehly, R. L. McCrory, C. P. Verdon et al., Fusion Eng. Des. 44, 35 (1999)] have been performed to prototype eventual campaigns on the National Ignition Facility (NIF) [E. I. Moses and C. R. Wuest, Fusion Sci. Technol. 43, 420 (2003)] to investigate the mixing of target materials. Spherical-implosion targets with equatorial defects have been irradiated with polar direct drive, a requirement for direct-drive experiments at NIF. The physics question addressed by these results is whether simulations can match data on 0th-order hydrodynamics and implosion symmetry, the most basic implosion features, with and without the defect. The successful testing of hydrodynamic simulations leads to better designs for experiments and guides accurate planning for polar-direct-drive-ignition studies on the NIF platform.

Cobble, J. A.; Murphy, T. J.; Schmitt, M. J.; Bradley, P. A.; Krashenninikova, N. S.; Obrey, K. A.; Hsu, S. C.; Tregillis, I. L.; Magelssen, G. R.; Wysocki, F. J.; Batha, S. H. [Los Alamos National Laboratory, Mail Stop E527, Los Alamos, New Mexico 87545 (United States)

2012-12-15T23:59:59.000Z

39

Experimental investigation of direct injection charge cooling in optical GDI engine using tracer-based PLIF technique  

Science Journals Connector (OSTI)

Abstract Investigation of direct injection charge cooling effects is indispensable in design and development of new combustion systems for Gasoline Direct Injection (GDI) engines. The charge cooling can be utilized to increase engine volumetric efficiency or compression ratio. It can be employed to suppress pre-ignition of highly boosted downsized engines or knocking combustion of naturally aspirated engines. The main purpose of this work was to develop an experimental setup for quantitative measurements of charge cooling during fuel injection process inside the combustion chamber of a GDI engine with optical access. For this purpose a tracer-based two-line Planar Laser Induced Fluorescence (PLIF) technique was implemented for the measurements. A specially designed Constant Volume Chamber (CVC) was utilized for quasi in situ calibration measurement so in-cylinder charge temperature measurements can be achieved independent of the photophysical model of dopant tracer. The thermometry technique was evaluated by measurements of average in-cylinder charge temperature during compression stroke for both motoring and firing cycles and comparing the results with temperature values calculated from in-cylinder pressure data assuming a polytropic compression. The PLIF technique was successfully utilized to quantify the extend of global temperature decrease as a result of direct injection charge cooling of two injection timings of 90 and 250 °CA ATDC and two injection quantities of 10 and 30 mg/cycle. Test results demonstrated the capability of the two-line PLIF thermometry technique in quantitative study of direct injection charge cooling effects.

Mohammadreza Anbari Attar; Mohammad Reza Herfatmanesh; Hua Zhao; Alasdair Cairns

2014-01-01T23:59:59.000Z

40

Gasoline direct injection: Actual trends and future strategies for injection and combustion systems  

SciTech Connect

Recent developments have raised increased interest on the concept of gasoline direct injection as the most promising future strategy for fuel economy improvement of SI engines. The general requirements for mixture preparation and combustion systems in a GDI engine are presented in view of known and actual systems regarding fuel economy and emission potential. The characteristics of the actually favored injection systems are discussed and guidelines for the development of appropriate combustion systems are derived. The differences between such mixture preparation strategies as air distributed fuel and fuel wall impingement are discussed, leading to the alternative approach to the problem of mixture preparation with the fully air distributing concept of direct mixture injection.

Fraidl, G.K.; Piock, W.F.; Wirth, M.

1996-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "ignition direct injection" 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

Direct-Drive Inerital Confinement Fusion Research at the Laboratory for Laser Energetics: Charting the Path to Thermonuclear Ignition  

SciTech Connect

Significant theoretical and experimental progress continues to be made at the University of Rocheter's Laboratory for Laser Energetics (LLE), charting the path to direct-drive inertial confinement fusion (ICF) ignition. Direct drive offers the potential for higher-gain implosions than x-ray drive and is a leading candidate for an inertial fusion enery power plant.

McCrory, R.L.; Regan, S.P.; Loucks, S.J.; Meyerhofer, D.D.; Skupsky, S.; Betti, R.; Boehly, T.R.; Craxton, R.S.; Collins, T.J.B.; Delettrez, J.A.; Edgell, D.; Epstein, R.; Fletcher, K.A.; Freeman, C.; Frenje, J.A.; Glebov, V.Yu.; Goncharov, V.N.; Harding, D.R.; Igumenshchev, I.V.; Keck, R.L.; Kilkenny, J.D.; Knauer, J.P.; Li, C.K.; Marciante, J.; Marozas, J.A.; Marshall, F.J.; Maximov, A.V.; McKenty, P.W.; Myatt, J.; Padalino, S.; Petrasso, R.D.; Radha, P.B.; Sangster, T.C.; Seguin, F.H.; Seka, W.; Smalyuk, V.A.; Soures, J.M.; Stoeckl, C.; Yaakobi, B.; Zuegel, J.D.

2005-10-07T23:59:59.000Z

42

Direct numerical simulation of ignition front propagation in a constant volume with temperature inhomogeneities. I. Fundamental analysis and diagnostics  

SciTech Connect

The influence of thermal stratification on autoignition at constant volume and high pressure is studied by direct numerical simulation (DNS) with detailed hydrogen/air chemistry with a view to providing better understanding and modeling of combustion processes in homogeneous charge compression-ignition engines. Numerical diagnostics are developed to analyze the mode of combustion and the dependence of overall ignition progress on initial mixture conditions. The roles of dissipation of heat and mass are divided conceptually into transport within ignition fronts and passive scalar dissipation, which modifies the statistics of the preignition temperature field. Transport within ignition fronts is analyzed by monitoring the propagation speed of ignition fronts using the displacement speed of a scalar that tracks the location of maximum heat release rate. The prevalence of deflagrative versus spontaneous ignition front propagation is found to depend on the local temperature gradient, and may be identified by the ratio of the instantaneous front speed to the laminar deflagration speed. The significance of passive scalar mixing is examined using a mixing timescale based on enthalpy fluctuations. Finally, the predictions of the multizone modeling strategy are compared with the DNS, and the results are explained using the diagnostics developed. (author)

Chen, Jacqueline H.; Hawkes, Evatt R.; Sankaran, Ramanan [Reacting Flow Research Department, Combustion Research Facility, Sandia National Laboratories, P.O. Box 969 MS 9051, Livermore, CA 94551-0969 (United States); Mason, Scott D. [Lockheed Martin Corporation, Sunnyvale, CA 94089 (United States); Im, Hong G. [Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109-2125 (United States)

2006-04-15T23:59:59.000Z

43

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

44

Engines - Spark Ignition Engines  

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

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

45

Fast Ignition  

NLE Websites -- All DOE Office Websites (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...

46

Calibraton of a Directly Injected Natural Gas HD Engine for Class...  

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

Calibraton of a Directly Injected Natural Gas HD Engine for Class 8 Truck Applications Calibraton of a Directly Injected Natural Gas HD Engine for Class 8 Truck Applications This...

47

Fact #720: March 26, 2012 Eleven Percent of New Light Trucks Sold have Gasoline Direct Injection  

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

Gasoline direct fuel injection (GDI) allows fuel to be injected directly into the cylinder so the timing and shape of the fuel mist can be controlled more precisely. The improved combustion and...

48

Comparison of propane and methane performance and emissions in a turbocharged direct injection dual fuel engine  

SciTech Connect

With increasingly restrictive NO x and particulate matter emissions standards, the recent discovery of new natural gas reserves, and the possibility of producing propane efficiently from biomass sources, dual fueling strategies have become more attractive. This paper presents experimental results from dual fuel operation of a four-cylinder turbocharged direct injection (DI) diesel engine with propane or methane (a natural gas surrogate) as the primary fuel and diesel as the ignition source. Experiments were performed with the stock engine control unit at a constant speed of 1800 rpm, and a wide range of brake mean effective pressures (BMEPs) (2.7-11.6 bars) and percent energy substitutions (PESs) of C 3 H 8 and CH 4. Brake thermal efficiencies (BTEs) and emissions (NO x, smoke, total hydrocarbons (THCs), CO, and CO 2) were measured. Maximum PES levels of about 80-95% with CH 4 and 40-92% with C 3 H 8 were achieved. Maximum PES was limited by poor combustion efficiencies and engine misfire at low loads for both C 3 H 8 and CH 4, and the onset of knock above 9 bar BMEP for C 3 H 8. While dual fuel BTEs were lower than straight diesel BTEs at low loads, they approached diesel BTE values at high loads. For dual fuel operation, NO x and smoke reductions (from diesel values) were as high as 66-68% and 97%, respectively, but CO and THC emissions were significantly higher with increasing PES at all engine loads

Gibson, C. M.; Polk, A. C.; Shoemaker, N. T.; Srinivasan, K. K.; Krishnan, S. R.

2011-04-20T23:59:59.000Z

49

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

50

Iron beam acceleration using direct plasma injection scheme  

SciTech Connect

A new set of vanes of radio frequency quadrupole (RFQ) accelerator was commissioned using highly charged iron beam. To supply high intensity heavy ion beams to the RFQ, direct plasma injection scheme (DPIS) with a confinement solenoid was adopted. One of the difficulties to utilize the combination of DPIS and a solenoid field is a complexity of electro magnetic field at the beam extraction region, since biasing high static electric field for ion extraction, RFQ focusing field, and the solenoid magnetic field fill the same space simultaneously. To mitigate the complexity, a newly designed magnetic field clamps were used. The intense iron beam was observed with bunched structure and the total accelerated current reached 2.5 nC.

Okamura, M., E-mail: okamura@bnl.gov [Brookhaven National Laboratory, Upton, New York 11973 (United States); RIKEN-BNL Research Center, Upton, New York 11973 (United States); Kanesue, T. [Brookhaven National Laboratory, Upton, New York 11973 (United States)] [Brookhaven National Laboratory, Upton, New York 11973 (United States); Yamamoto, T. [Waseda University, Shinjuku, Tokyo 169-8555 (Japan)] [Waseda University, Shinjuku, Tokyo 169-8555 (Japan); Fuwa, Y. [Kyoto University, Uji, Kyoto 611-0011 (Japan) [Kyoto University, Uji, Kyoto 611-0011 (Japan); RIKEN, Wako, Saitama 351-0198 (Japan)

2014-02-15T23:59:59.000Z

51

Multiple Injection and Boosting Benefits for Improved Fuel Consumption on a Spray Guided Direct Injection Gasoline Engine  

Science Journals Connector (OSTI)

The combination of turbocharging and direct injection offers a significant potential for SI engines to improve fuel consumption, specific power output, raw emissions and ... shows the latest results of the T-SGDI...

Jason King; Oliver Böcker

2013-01-01T23:59:59.000Z

52

Effect of stratified water injection on exhaust gases and fuel consumption of a direct injection diesel engine  

Science Journals Connector (OSTI)

The direct injection Diesel engine with its specific fuel consumption of about 200 g/kWh is one of the most efficient thermal engines. However in case of relatively low CH...x...concentration in the exhaust gas t...

Rainer Pauls; Christof Simon

2004-01-01T23:59:59.000Z

53

An Experimental Study on the Two-Stage Combustion Characteristics of a Direct-Injection-Type HCCI Engine  

Science Journals Connector (OSTI)

Department of Mechanical Engineering, Hanyang University, 1271 Sa-1 Dong, Sangrok-gu Ansan-si, Gyenggi-do, 426-791, Korea ... This research was achieved using a direct-injection-type diesel method during the intake stroke in real single-cylinder engines, and observations were made regarding the cool and hot flame characteristics, according to the air:fuel ratio and engine speed (given in units of rpm), an additive that influences the auto-ignition and the start times, and the combustion and emission characteristics, according to these times. ... This work was supported by the “Development of techniques on the fundamental and practical use of a HCCI” project at Korea Automotive Technology Institute, 2004. ...

Kihyung Lee; Changsik Lee; Jeaduk Ryu; Hyungmin Kim

2005-02-12T23:59:59.000Z

54

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

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

55

Evaluation of Oxydiesel as a Fuel for Direct-Injection Compression-Ignition Engines  

E-Print Network (OSTI)

speed and maximum power for 500 hours on a blend of ethanol, No. 2 diesel, and an additive as compared and diesel with a special additive, has been shown to be a promising new alternative fuel for existing diesel the mixing of diesel fuel with ethanol. The Illinois DCCA has embarked on a widespread research program

Illinois at Urbana-Champaign, University of

56

3-Cylinder Turbocharged Gasoline Direct Injection: A High Value Solution for Euro VI Emissions  

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

3-cylindery gasoline direct injection engines offer similar value in CO2 reduction capability (Euros/% CO2 reduction) at a significantly lower on-cost.

57

Laser Ignition  

NLE Websites -- All DOE Office Websites (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...

58

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

59

Premixed direct injection nozzle for highly reactive fuels  

DOE Patents (OSTI)

A fuel/air mixing tube for use in a fuel/air mixing tube bundle is provided. The fuel/air mixing tube includes an outer tube wall extending axially along a tube axis between an inlet end and an exit end, the outer tube wall having a thickness extending between an inner tube surface having a inner diameter and an outer tube surface having an outer tube diameter. The tube further includes at least one fuel injection hole having a fuel injection hole diameter extending through the outer tube wall, the fuel injection hole having an injection angle relative to the tube axis. The invention provides good fuel air mixing with low combustion generated NOx and low flow pressure loss translating to a high gas turbine efficiency, that is durable, and resistant to flame holding and flash back.

Ziminsky, Willy Steve; Johnson, Thomas Edward; Lacy, Benjamin Paul; York, William David; Uhm, Jong Ho; Zuo, Baifang

2013-09-24T23:59:59.000Z

60

Dry low NOx combustion system with pre-mixed direct-injection secondary fuel nozzle  

DOE Patents (OSTI)

A combustion system includes a first combustion chamber and a second combustion chamber. The second combustion chamber is positioned downstream of the first combustion chamber. The combustion system also includes a pre-mixed, direct-injection secondary fuel nozzle. The pre-mixed, direct-injection secondary fuel nozzle extends through the first combustion chamber into the second combustion chamber.

Zuo, Baifang; Johnson, Thomas; Ziminsky, Willy; Khan, Abdul

2013-12-17T23:59:59.000Z

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


61

Investigation of Cluster-Nozzle Concepts for Direct Injection Diesel Engines  

E-Print Network (OSTI)

Investigation of Cluster-Nozzle Concepts for Direct Injection Diesel Engines Von der Fakultät für Investigation of Cluster-Nozzle Concepts for Direct Injection Diesel Engines WICHTIG: D 82 überprüfen !!! #12" in Zusammenarbeit mit General Motors R&D and Strategic Planning, Warren, MI, USA durchgeführt. Ein Teil der Arbeit

Peters, Norbert

62

Direct injection tunnel spectroscopy of a p-n junction Edward M. Likovich,1  

E-Print Network (OSTI)

Direct injection tunnel spectroscopy of a p-n junction Edward M. Likovich,1 Kasey J. Russell,1,a tunnel injection of electrons. In contrast to the metal-base transistor design of conventional ballistic the semiconductor before they scatter and thermal- ize to the chemical potential of the base layer. For systems

Russell, Kasey

63

A Detailed Multi-Zone Thermodynamic Simulation For Direct-Injection Diesel Engine Combustion  

E-Print Network (OSTI)

A detailed multi-zone thermodynamic simulation has been developed for the direct-injection (DI) diesel engine combustion process. For the purpose of predicting heterogeneous type combustion systems, the model explores the formation of pre...

Xue, Xingyu 1985-

2012-11-15T23:59:59.000Z

64

Numerical modeling of combustion processes and pollutant formations in direct-injection diesel engines  

Science Journals Connector (OSTI)

The Representative Interactive Flamelet (RIF) concept has been applied to numerically simulate the combustion processes and pollutant formation in the direct injection...X formation including thermal NO path, pro...

Seong-Ku Kim; Joon Kyu Lee; Yong-Mo Kim; Jae-Hyun Ahn

2002-07-01T23:59:59.000Z

65

Combustion and emissions of a direct injection gasoline engine using biofuels.  

E-Print Network (OSTI)

??Impact of biofuel (2-methlyfuran, 2,5-dimethylfuran and ethanol) on the performance of a gasoline direct injection engine has been investigated. MF demonstrates better knock resistance properties… (more)

Wang, Chongming

2014-01-01T23:59:59.000Z

66

Laser Ignition  

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

Laser Ignition Laser Ignition Laser Ignition A first excitation laser or other excitation light source is used in tandem with an ignitor laser to provide a compact, durable, engine deployable fuel ignition laser system. Available for thumbnail of Feynman Center (505) 665-9090 Email Laser Ignition A first excitation laser or other excitation light source is used in tandem with an ignitor laser to provide a compact, durable, engine deployable fuel ignition laser system. Reliable fuel ignition is provided over a wide range of fuel conditions by using a single remote excitation light source for one or more small lasers located proximate to one or more fuel combustion zones. In two embodiments the beam from the excitation light source is split with a portion of it going to the ignitor laser and a second portion

67

Development of a polar direct-drive platform for studying inertial confinement fusion implosion mix on the National Ignition Facility  

SciTech Connect

Experiments were performed to develop a platform for the simultaneous measurement of mix and its effects on fusion burn. Two polar direct drive implosions of all-plastic capsules were conducted for the first time on the National Ignition Facility (NIF). To measure implosion trajectory and symmetry, area image backlighting of these capsules was also employed for the first time on NIF, an advance over previous 1-D slit imaging experiments, providing detailed symmetry data of the capsules as they imploded. The implosion trajectory and low-mode asymmetry seen in the resultant radiographs agreed with pre-shot predictions even though the 700 kJ drive energy produced laser beam intensities exceeding laser-plasma instability thresholds. Post-shot simulations indicate that the capsule yield was reduced by a factor of two compared to pre-shot predictions owing to as-shot laser drive asymmetries. The pre-shot predictions of bang time agreed within 200 ps with the experimental results. The second shot incorporated a narrow groove encircling the equator of the capsule. A predicted yield reduction factor of three was not observed.

Schmitt, Mark J.; Bradley, Paul A.; Cobble, James A.; Fincke, James R.; Hakel, Peter; Hsu, Scott C.; Krasheninnikova, Natalia S.; Kyrala, George A.; Magelssen, Glenn R.; Montgomery, David S.; Murphy, Thomas J.; Obrey, Kimberly A.; Shah, Rahul C.; Tregillis, Ian L.; Baumgaertel, Jessica A.; Wysocki, Frederick J.; Batha, Steven H. [Los Alamos National Laboratory, MS F699, Los Alamos, New Mexico 87545 (United States)] [Los Alamos National Laboratory, MS F699, Los Alamos, New Mexico 87545 (United States); Stephen Craxton, R.; McKenty, Patrick W. [Laboratory for Laser Energetics, University of Rochester, 250 E. River Road, Rochester, New York 14623 (United States)] [Laboratory for Laser Energetics, University of Rochester, 250 E. River Road, Rochester, New York 14623 (United States); Fitzsimmons, Paul [General Atomics, 3550 General Atomics Court, San Diego, California 92121 (United States)] [General Atomics, 3550 General Atomics Court, San Diego, California 92121 (United States); and others

2013-05-15T23:59:59.000Z

68

Study of mixture formation and early flame development in a research GDI (gasoline direct injection) engine through numerical simulation and UV-digital imaging  

Science Journals Connector (OSTI)

Abstract The analysis of the mixture formation and early combustion processes in a slightly lean burn gasoline direct injection (GDI) engine is performed by using experimental and numerical techniques. UV–visible natural emission digital imaging is applied in the optically accessible combustion chamber of a research engine. This is equipped with the four-valve head and the same injection system of a commercial turbocharged engine. Optical accessibility is obtained through a quartz window placed on the piston head. Numerical simulations are performed by means of a 3D model developed within the AVL FireTM environment, which exploits an in-house developed sub-model for simulating the spray dynamics. Tests are carried out using commercial gasoline. The cyclic variability of the engine is first analysed in order to properly define a reference average pressure cycle to be used for the validation of the numerical model. This last is then proved as being highly predictive as the start of injection is moved in the working cycle. The main effects of the injection and ignition timing on the characteristic flame development angles, namely on the flame initiation and propagation, are analysed. Flame initiation is visualised both numerically and experimentally.

M. Costa; L. Marchitto; S.S. Merola; U. Sorge

2014-01-01T23:59:59.000Z

69

Development of a direct-injected natural gas engine system for heavy-duty vehicles: Final report phase 2  

SciTech Connect

This report summarizes the results of Phase 2 of this contract. The authors completed four tasks under this phase of the subcontract. (1) They developed a computational fluid dynamics (CFD) model of a 3500 direct injected natural gas (DING) engine gas injection/combustion system and used it to identify DING ignition/combustion system improvements. The results were a 20% improvement in efficiency compared to Phase 1 testing. (2) The authors designed and procured the components for a 3126 DING engine (300 hp) and finished assembling it. During preliminary testing, the engine ran successfully at low loads for approximately 2 hours before injector tip and check failures terminated the test. The problems are solvable; however, this phase of the program was terminated. (3) They developed a Decision & Risk Analysis model to compare DING engine technology with various other engine technologies in a number of commercial applications. The model shows the most likely commercial applications for DING technology and can also be used to identify the sensitivity of variables that impact commercial viability. (4) MVE, Inc., completed a preliminary design concept study that examines the major design issues involved in making a reliable and durable 3,000 psi LNG pump. A primary concern is the life of pump seals and piston rings. Plans for the next phase of this program (Phase 3) have been put on indefinite hold. Caterpillar has decided not to fund further DING work at this time due to limited current market potential for the DING engine. However, based on results from this program, the authors believe that DI natural gas technology is viable for allowing a natural gas-fueled engine to achieve diesel power density and thermal efficiency for both the near and long terms.

Cox, G.B.; DelVecchio, K.A.; Hays, W.J.; Hiltner, J.D.; Nagaraj, R.; Emmer, C.

2000-03-02T23:59:59.000Z

70

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

71

Ignition system  

SciTech Connect

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

72

An initial assessment of three-dimensional polar direct drive capsule asymmetries for implosions at the National Ignition Facility  

SciTech Connect

The National Ignition Facility (NIF) provides a unique opportunity to study implosion physics with nuclear yield. The use of polar direct drive (PDD) [A. M. Cok, R. S. Craxton, and P. W. McKenty, Phys. Plasmas 15, 082705 (2008)] provides a simple platform for the experimental studies without expensive optics upgrades to NIF. To determine the optimum PDD laser pointing geometry on NIF and provide a baseline for validating inertial confinement fusion codes against experiments for symmetric and asymmetric implosions, computer simulations using the 3D radiation-hydrodynamics code hydra[M. M. Marinak, R. E. Tipton, O. L. Landen, T. J. Murphy, P. Amendt, S. W. Haan, S. P. Hatchett, C. J. Keane, R. McEachern, and R. Wallace, Phys. Plasmas 3, 2070 (1996)] were preformed. The upper hemisphere of a DT-filled CH capsule was imploded by 96 NIF beams in a PDD configuration. Asymmetries in both polar and equatorial directions around the capsule were observed, with the former dominating the latter. Analysis of the simulation results indicates that the lack of symmetry in the initial power density profile (during the first 200 ps of the implosion) is a primary cause of late-time asymmetry in the implosion as well as decreased yield. By adjusting the laser pointings, the symmetry and total neutron yield were improved. Simulations with dropped quads (four of the NIF laser system's 192 beamlines) without repointing worsen the overall symmetry by a factor of 10 (with respect to rms radial variation around the capsule) and reduce neutron yield by a factor of 2. Both of these degraded implosion characteristics are restored by azimuthal repointing of the remaining quads.

Krasheninnikova, Natalia S.; Finnegan, Sean M.; Schmitt, Mark J. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2012-01-15T23:59:59.000Z

73

Supernovae from direct collisions of white dwarfs and the role of helium shell ignition  

E-Print Network (OSTI)

Models for supernovae (SNe) arising from thermonuclear explosions of white dwarfs (WDs) have been extensively studied over the last few decades, mostly focusing on the single degenerate (accretion of material of a WD) and double degenerate (WD-WD merger) scenarios. In recent years it was suggested that WD-WD direct collisions provide an additional channel for such explosions. Here we extend the studies of such explosions, and explore the role of Helium-shells in affecting the thermonuclear explosions. We study both the impact of low-mass helium ($\\sim0.01$ M$_{\\odot})$ shells, as well as high mass shells ($\\ge0.1$ M$_{\\odot}$). We find that detonation of the massive helium layers precede the detonation of the WD Carbon-Oxygen (CO) bulk during the collision and can change the explosive evolution and outcomes for the cases of high mass He-shells. In particular, the He-shell detonation propagates on the WD surface and inefficiently burns material prior to the CO detonation that later follows in the central parts...

Papish, Oded

2015-01-01T23:59:59.000Z

74

A diesel engine study of conventional and alternative diesel and jet fuels: Ignition and emissions characteristics  

Science Journals Connector (OSTI)

Abstract Measurements of ignition delay, CO and NO emissions, and fuel consumption were carried out in a light-duty single-cylinder direct-injection diesel engine for operation with petroleum and alternative hydroprocessed and Fischer–Tropsch diesel and jet fuels. Ignition measurements carried out for a fixed engine speed and injection timing quantify the decrease in in-cylinder ignition delay with increasing derived cetane number (DCN) over a range of DCN relevant to diesel engine operation (DCN = 40–80) and show no discernible dependence of ignition delay on other fuel properties. Brake specific fuel consumption (BSFC) was found to decrease with increasing DCN with strong correlation due to a reduction in ignition time for fixed-injection-timed operation. Brake specific CO emissions were also found to decrease with increasing DCN due to increased time provided for CO burn out due to earlier ignition. Brake specific NO emissions were found to decrease with increasing hydrogen-to-carbon (H/C) ratio, due to the lower peak combustion temperatures and thermal \\{NOx\\} occurring for fuels with higher H/C.

Sandeep Gowdagiri; Xander M. Cesari; Mingdi Huang; Matthew A. Oehlschlaeger

2014-01-01T23:59:59.000Z

75

Quantitative in-cylinder NO-LIF imaging in a realistic gasoline engine with spray-guided direct injection  

E-Print Network (OSTI)

Quantitative in-cylinder NO-LIF imaging in a realistic gasoline engine with spray-guided direct of engines with gasoline direct injection. Exhaust gas aftertreatment requires storage catalysts fractions in a gasoline engine with spray-guided direct injection using laser-induced fluorescence (LIF

Lee, Tonghun

76

2010-01-0166 Ethanol Content Estimation in Flex Fuel Direct Injection  

E-Print Network (OSTI)

2010-01-0166 Ethanol Content Estimation in Flex Fuel Direct Injection Engines Using In (FFVs) are able to operate on a blend of ethanol and gasoline in any volumetric concen- tration of up to 85% ethanol (93% in Brazil). The estima- tion of ethanol content is crucial for optimized and robust

Stefanopoulou, Anna

77

CARBON SEQUESTRATION VIA DIRECT INJECTION Howard J. Herzog, Ken Caldeira, and Eric Adams  

E-Print Network (OSTI)

CARBON SEQUESTRATION VIA DIRECT INJECTION Howard J. Herzog, Ken Caldeira, and Eric Adams and sequestration. Carbon sequestration is often associated with the planting of trees. As they mature, the trees INTRODUCTION The build-up of carbon dioxide (CO2) and other greenhouse gases in the Earth's atmosphere has

78

Numerical Modeling and Experimental Study of Combustion and Soot Formation in a Direct Injection Diesel Engine  

Science Journals Connector (OSTI)

Numerical Modeling and Experimental Study of Combustion and Soot Formation in a Direct Injection Diesel Engine ... The major problems associated with diesel engines are the high levels of nitrogen oxides (NOX) and particulate emissions. ... (11)?Flagan, R. C.; Seinfeld, J. H. Fundamentals of Air Pollution Engineering; Prentice Hall Inc.:? New York, 1988. ...

T. L. Chan; X. B. Cheng

2007-04-10T23:59:59.000Z

79

Formation of Nickel Silicide from Direct-Liquid-Injection Chemical-Vapor-Deposited Nickel Nitride Films  

E-Print Network (OSTI)

. Published April 28, 2010. Metal silicides such as TiSi2 and CoSi2 have been commonly used as the contactsFormation of Nickel Silicide from Direct-Liquid-Injection Chemical-Vapor-Deposited Nickel Nitride as the intermediate for subsequent conversion into nickel silicide NiSi , which is a key material for source, drain

80

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

Note: This page contains sample records for the topic "ignition direct injection" 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

Ignition Experiments  

NLE Websites -- All DOE Office Websites (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...

82

Development of Innovative Combustion Processes for a Direct-Injection Diesel Engine  

SciTech Connect

In support of the Partnership for a New Generation Vehicle (PNGV) emissions and fuel economy goals, a small-bore, high-speed, direct-injection (HSDI) diesel facility in which to conduct research into the physics of the combustion process relevant to these engines has been developed. The characteristics of this facility are described, and the motivation for selecting these characteristics and their relation to high efficiency, low-emission HSDI engine technology is discussed.

John Dec; Paul Miles

1999-01-01T23:59:59.000Z

83

Performance and Emissions of Direct Injection Diesel Engine Fueled with Diesel Fuel Containing Dissolved Methane  

Science Journals Connector (OSTI)

State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China ... soot and nitrogen oxides, from direct injection Diesel engines, engineers have proposed various solns., one of which is the use of a gaseous fuel as a partial supplement for liq. ... (16)?Heywood, J. B. Internal Combustion Engine Fundamentals; McGraw-Hill:? New York, 1988. ...

Junqiang Zhang; Deming Jiang; Zuohua Huang; Xibin Wang; Qi Wei

2006-01-19T23:59:59.000Z

84

New Phenomenological Six-Zone Combustion Model for Direct-Injection Diesel Engines  

Science Journals Connector (OSTI)

New Phenomenological Six-Zone Combustion Model for Direct-Injection Diesel Engines ... Nevertheless, to comply with ever more stringent emission standards, particularly regarding NOx and particulate matter (PM) emissions, such as EURO 6 in Europe, diesel engine manufacturers have to find new in-cylinder combustion strategies and/or complex after-treatment devices to reduce their emissions. ... Heywood, J. B. Internal Combustion Engines Fundamentals; McGraw-Hill: New York, 1988. ...

Alain Maiboom; Xavier Tauzia; Samiur Rahman Shah; Jean-François Hétet

2009-01-09T23:59:59.000Z

85

Determination of desorption efficiency utilizing direct injection: a dynamic calibration system and phase equilibrium  

E-Print Network (OSTI)

) Ronald H. Williams B. S. , Purdue University B. S. , University of Arkansas Chairman of Advisory Committee: Dr . R. B. Konzen Three methods for determining desorption efficiency for or ganic solvents adsorbed on activated charcoal were compared.... The three methods involved a dynamic calibra- tion system, direct injection, and phase equilibrium. The methods differed in the manner in which the analyte was placed on the adsorbent. The desorption efficiencies ob- tained using the dynamic calibration...

Williams, Ronald H

2012-06-07T23:59:59.000Z

86

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

87

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

88

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

89

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

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

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

90

An experimental investigation of high performance natural gas engine with direct injection  

Science Journals Connector (OSTI)

This paper presents experimental results of a new compressed natural gas direct injection (CNG-DI) engine that has been developed from modification of a multi cylinder gasoline port injection (PI) engine. The original gasoline-PI engine was also modified to a CNG bi-fuel system. The test results obtained from CNG fuel using two different systems (i.e. bi-fuel and DI) have been investigated and compared with the original gasoline engine. The objective of this investigation is to compare the test results between CNG-DI, with CNG-BI and gasoline-PI engines with the same displacement volume. It was found that the CNG-DI engine produces similar brake power at 6000 rpm and wide open throttle (WOT) but produces higher brake power at part load condition as compared to the original gasoline. The CNG-BI engine produces 23% lower brake power than the CNG-DI engine. The average brake specific fuel consumption (BSFC) of the CNG-DI engine was 0.28% and 8% lower than gasoline-PI and CNG-BI engines respectively. The CNG-DI engine reduces 42% \\{NOx\\} emission as compared to the base engine. However, the CNG-DI engine produces higher HC and CO emissions as compared to the base engine. This paper discusses a review on the direct injection (DI) natural gas engine with new information along with other investigations.

M.A. Kalam; H.H. Masjuki

2011-01-01T23:59:59.000Z

91

Controlling combustion noise in direct injection diesel engine through mechanical vibration measurement  

Science Journals Connector (OSTI)

The next generations of direct injection diesel engines have greatly improved their performances compared with petrol engines. However, one of the pending subjects is the noise and vibration levels, due to working cycle itself. The design effort to reduce the emissions of noise and vibration transmitted to the vehicle's driver could be lessened because of the assembly process variation. In this paper, a procedure to control this variation has been suggested in order to maintain noise and vibration performances within the limits of design.

J.A. Calvo; V. Diaz; J.L. San Roman

2005-01-01T23:59:59.000Z

92

Effect of direct liquid water injection and interdigitated flow field on the performance of proton exchange membrane fuel cells  

E-Print Network (OSTI)

70-108B One Cyclotron Road Berkeley, California 94720 December 2, 1997 Key Words: Proton Exchange Membrane fuel cells, humidification, gas distribution, direct liquid water injection, interdigitated flow fields. * Corresponding... of the catalyst layers were made of waterproof, carbon fiber cloths. Liquid water was injected by two metering pumps into two heated stainless steel coils, where it was preheated to the cell operating temperatures, and then directly into the gas streams...

Wood, D. L.; Yi, Y. S.; Nguyen, Trung Van

1998-01-01T23:59:59.000Z

93

Linear accelerator design study with direct plasma injection scheme for warm dense matter  

SciTech Connect

Warm Dense Matter (WDM) is a challenging science field, which is related to heavy ion inertial fusion and planetary science. It is difficult to expect the behavior because the state with high density and low temperature is completely different from ideal condition. The well-defined WDM generation is required to understand it. Moderate energy ion beams ({approx} MeV/u) slightly above Bragg peak is an advantageous method for WDM because of the uniform energy deposition. Direct Plasma Injection Scheme (DPIS) with a Interdigital H-mode (IH) accelerator has a potential for the beam parameter. We show feasible parameters of the IH accelerator for WDM. WDM physics is a challenging science and is strongly related to Heavy Ion Fusion science. WDM formation by Direct Plasma Injection Scheme (DPIS) with IH accelerator, which is a compact system, is proposed. Feasible parameters for IH accelerator are shown for WDM state. These represents that DPIS with IH accelerator can access a different parameter region of WDM.

Kondo, K.; Kanesue, T; Okamura, M.

2011-03-28T23:59:59.000Z

94

Experimental investigation of the stimulated Brillouin scattering growth and saturation at 526 and 351 nm for direct drive and shock ignition  

SciTech Connect

We have designed experiments to study the effect of the laser wavelength (0.527 versus 0.351 {mu}m) on the coupling efficiency in plasma conditions relevant to compression and shock ignition (SI) schemes in different intensity regimes. A difficult issue was to produce interaction conditions that are equivalent for the two wavelengths. This was obtained by using plasma preformed from a solid target with a plasma-preforming beam at the same wavelength as the interaction beam. This produced an almost exponential density profile from vacuum to the critical density of the interaction beam in which all interaction mechanisms are taken into account. The growth and saturation of stimulated Brillouin scattering (SBS) have been measured at the two wavelengths, in backward as well as in near-backward directions. We have found that the SBS intensity threshold is {approx}1.5 times higher at 3{omega} than at 2{omega} in agreement with the I{lambda} dependence of the SBS gain. The SBS behaviour is very well reproduced by the linear calculations of the postprocessor PIRANAH, giving us confidence that we have a good control of the relevance of the experimental conditions for the study of the laser wavelength effect on laser-plasma coupling. When SBS reaches the saturation regime, same levels of reflectivity are measured at 2 and 3{omega}. Numerical simulations were performed with the paraxial code HERA to study the contribution of the fluid mechanisms in the saturation of SBS, showing that pump depletion and interplay with filamentation are likely to be the most important processes in SBS saturation for these conditions. This scenario also applies to the SBS of shock ignition high-intensity beams.

Depierreux, S.; Loiseau, P.; Tassin, V.; Masson-Laborde, P.-E.; Goyon, C. [CEA DAM DIF, F-91297 Arpajon (France); Michel, D. T.; Yahia, V. [CEA DAM DIF, F-91297 Arpajon (France); LULI, Ecole Polytechnique, CNRS, CEA, UPMC, 91128 Palaiseau (France); Stenz, C. [CELIA, Universite Bordeaux 1, 351 cours de la Liberation, 33405 Talence cedex (France); Labaune, C. [LULI, Ecole Polytechnique, CNRS, CEA, UPMC, 91128 Palaiseau (France)

2012-01-15T23:59:59.000Z

95

Direct injection of ionospheric O sup + into the dayside low latitude boundary layer  

SciTech Connect

Observations from the AMPTE/Charge Composition Explorer (AMPTE/CCE) indicate the presence of two distinct O{sup +} populations in the dayside subsolar low latitude boundary layer during some periods of northward Interplanetary Magnetic Field (IMF). The first population is O{sup +} convected into the boundary layer from the outer magnetosphere and has been reported previously. It is suggested here that the new, second, O{sup +} population is injected into the dayside boundary layer directly from the high latitude ionosphere. This second population can have a significant density and distinct characteristics such as field-aligned flow relative to boundary layer H{sup +} that modify both the plasma composition and dynamics in the low latitude boundary layer. {copyright} American Geophysical Union 1989

Fuselier, S.A.; Klumpar, D.M.; Peterson, W.K.; Shelley, E.G. (Lockheed Palo Alto Research Laboratory, Palo Alto, California (US))

1989-10-01T23:59:59.000Z

96

Optical-Engine Study of a Low-Temperature Combustion Strategy Employing a Dual-Row, Narrow-Included-Angle Nozzle and Early, Direct Injection of Diesel Fuel  

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

Insight into mechanisms causing observed sharp emissions increase with diesel fuel injection is gained through experiments in an optical engine employing a similar low-temperature combustion strategy of early, direct injection of diesel fuel.

97

Rich catalytic injection  

DOE Patents (OSTI)

A gas turbine engine includes a compressor, a rich catalytic injector, a combustor, and a turbine. The rich catalytic injector includes a rich catalytic device, a mixing zone, and an injection assembly. The injection assembly provides an interface between the mixing zone and the combustor. The injection assembly can inject diffusion fuel into the combustor, provides flame aerodynamic stabilization in the combustor, and may include an ignition device.

Veninger, Albert (Coventry, CT)

2008-12-30T23:59:59.000Z

98

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

99

Fast ignition of inertial confinement fusion targets  

SciTech Connect

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

100

Measurement of elemental speciation by liquid chromatography -- inductively coupled plasma mass spectrometry (LC-ICP-MS) with the direct injection nebulizer (DIN)  

SciTech Connect

This thesis is divided into 4 parts: elemental speciation, speciation of mercury and lead compounds by microbore column LC-ICP-MS with direct injection nebulization, spatially resolved measurements of size and velocity distributions of aerosol droplets from a direct injection nebulizer, and elemental speciation by anion exchange and size exclusion chromatography with detection by ICP-MS with direct injection nebulization. Tabs, figs, refs.

Shum, S.

1993-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "ignition direct injection" 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

Analysis of the injection process in direct injected natural gas engines. Part 1: Study of unconfined and in-cylinder plume behavior  

SciTech Connect

A study of natural gas (NG) direct injection (DI) processes has been performed using multidimensional computational fluid dynamics analysis. The purpose was to improve the understanding of mixing in DI NG engines. Calculations of injection into a constant-volume chamber were performed to document unconfined plume behavior. A full three-dimensional calculation of injection into a medium heavy-duty diesel engine cylinder was also performed to study plume behavior in engine geometries. The structure of the NG plume is characterized by a core of unmixed fuel confined to the near-field of the jet. This core contains the bulk of the unmixed fuel and is mixed by the turbulence generated by the jet shear layer. The NG plume development in the engine is dominated by combustion chamber surface interactions. A Coanda effect causes plume attachment to the cylinder head, which has a detrimental impact on mixing. Unconfined plume calculations with different nozzle hole sizes demonstrate that smaller nozzle holes are more effective at mixing the fuel and air.

Jennings, M.J.; Jeske, F.R. (Ricardo North America, Burr Ridge, IL (United States))

1994-10-01T23:59:59.000Z

102

Thermal ignition combustion system  

SciTech Connect

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

103

High-pressure late cycle direct injection of natural gas in a rail medium speed diesel engine  

SciTech Connect

The performance of an Electro-Motive Division (EMD) 567B, two-cylinder locomotive research engine, when operated on high-pressure/late-cycle injection of natural gas, is presented in this paper. A redesign and fabrication of the fuel system was undertaken to facilitate the consumption of natural gas. A small percentage of No.2 diesel fuel (DF-2) was used to ignite the natural gas. Engine performance, while running natural gas, resulted in matching rated speed and power with slightly lower thermal efficiency. Full power was achieved with a ratio of 99 percent natural gas and 1 percent diesel fuel. However, at high natural gas to diesel fuel ratios, audible knock was detected. The primary objective of the project was to establish technical feasibility of, and basic technology for, operating medium-speed rail diesel engines on high-pressure natural gas. Secondary objectives were to attain adequate engine performance levels for rail application, develop a system oriented toward retrofit of in-service locomotives, and realize any potential improvements in thermal efficiency due to use of the high-pressure/late-cycle approach.

Wakenell, J.F.; O'Neal, G.B.; Baker, Q.A.

1987-01-01T23:59:59.000Z

104

Formation of Nickel Silicide from Direct-liquid-injection Chemical-vapor-deposited Nickel Nitride Films  

SciTech Connect

Smooth, continuous, and highly conformal nickel nitride (NiN{sub x}) films were deposited by direct liquid injection (DLI)-chemical vapor deposition (CVD) using a solution of bis(N,N{prime}-di-tert-butylacetamidinato)nickel(II) in tetrahydronaphthalene as the nickel (Ni) source and ammonia (NH{sub 3}) as the coreactant gas. The DLI-CVD NiNx films grown on HF-last (100) silicon and on highly doped polysilicon substrates served as the intermediate for subsequent conversion into nickel silicide (NiSi), which is a key material for source, drain, and gate contacts in microelectronic devices. Rapid thermal annealing in the forming gas of DLI-CVD NiNx films formed continuous NiSi films at temperatures above 400 C. The resistivity of the NiSi films was 15{mu}{Omega} cm, close to the value for bulk crystals. The NiSi films have remarkably smooth and sharp interfaces with underlying Si substrates, thereby producing contacts for transistors with a higher drive current and a lower junction leakage. Resistivity and synchrotron X-ray diffraction in real-time during annealing of NiNx films showed the formation of a NiSi film at about 440 C, which is morphologically stable up to about 650 C. These NiSi films could find applications in future nanoscale complementary metal oxide semiconductor devices or three-dimensional metal-oxide-semiconductor devices such as Fin-type field effect transistors for the 22 nm technology node and beyond.

Li, Z.; Gordon, R; Li, H; Shenai, D; Lavoie, C

2010-01-01T23:59:59.000Z

105

Ignition distributor voltage generator  

SciTech Connect

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

106

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

107

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

108

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

109

Hydrocarbon emissions in a homogeneous direct-injection spark engine : gasoline and gasohol  

E-Print Network (OSTI)

In order to better understand the effects on hydrocarbon emissions of loading, engine temperature, fuel type, and injection timing, a series of experiments was performed. The effect of loading was observed by running the ...

Tharp, Ronald S

2008-01-01T23:59:59.000Z

110

Power, Efficiency, and Emissions Optimization of a Single Cylinder Direct-Injected Diesel Engine for Testing of Alternative Fuels through Heat Release Modeling  

E-Print Network (OSTI)

Power, Efficiency, and Emissions Optimization of a Single Cylinder Direct-Injected Diesel Engine for Testing of Alternative Fuels through Heat Release Modeling BY Jonathan Michael Stearns Mattson Submitted to the graduate degree program..., Efficiency, and Emissions Optimization of a Single Cylinder Direct-Injected Diesel Engine for Testing of Alternative Fuels through Heat Release Modeling BY Jonathan Michael Stearns Mattson...

Mattson, Jonathan Michael Stearns

2013-08-31T23:59:59.000Z

111

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

112

Thermal ignition combustion system  

SciTech Connect

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

113

Ultrafast and quantitative X-tomography and simulation of hollow-cone gasoline direct-injection sprays.  

SciTech Connect

Gasoline direct injection (GDI) has the potential to greatly improve internal combustion engine performance through precise control of the injection rate, timing, and combustion of the fuel. A thorough characterization of the hydrodynamics of fuel injection has to come from a precise, quantitative analysis of the sprays, especially in the near-nozzle region. A lack of knowledge of the fuel-spray dynamics has severely limited computational modeling of the sprays and design of improved injection systems. Previously, the structure and dynamics of highly transient fuel sprays have never been visualized or reconstructed in three dimensions (3D) due to numerous technical difficulties. By using an ultrafast x-ray detector and intense monochromatic x-ray beams from synchrotron radiation, the fine structures and dynamics of 1-ms GDI fuel sprays from an outwardly opening nozzle were elucidated by a newly developed, ultrafast, microsecond computed microtomography (CT) technique. In a time-resolved manner, many detailed features associated with the transient fuel flows are readily observable in the quantitatively reconstructed 3D fuel spray density distribution as a result of the quantitative CT technique. More importantly, a computational fluid dynamics (CFD) simulation based on the Taylor analogy breakup (TAB) model has also been performed using the boundary and initial conditions obtained from the experiment data. The experimental and numerical results are in good agreement quantitatively. These results not only reveal the characteristics of the GDI fuel sprays with unprecedented detail, but will also facilitate realistic computational fluid dynamic simulations in highly transient, multiphase systems.

Liu, X.; Im, K-S; Wang, Y.; Wang, J.; Tate, M.W.; Ercan, A.; Schuette, D.R.; Gruner, S.M. (X-Ray Science Division); (Cornell Univ.)

2007-01-01T23:59:59.000Z

114

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

SciTech Connect

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

115

Determination of Depleted Uranium in Urine via Isotope Ratio Measurements Using Large-Bore Direct Injection High Efficiency Nebulizer–Inductively Coupled Plasma Mass Spectrometry  

Science Journals Connector (OSTI)

Inductively coupled plasma mass spectrometry (ICP-MS), coupled with a large-bore direct injection high efficiency nebulizer (LB-DIHEN), was utilized to determine the concentration and...

Westphal, Craig S; McLean, John A; Hakspiel, Shelly J; Jackson, William E; McClain, David E; Montaser, Akbar

2004-01-01T23:59:59.000Z

116

Combustion analysis of a direct injection diesel engine when fuelled with sunflower methyl ester and its diesel blends  

Science Journals Connector (OSTI)

Uncertainty in the availability of petroleum-based fuels in the near future and stringent pollution norms have triggered a search for renewable and clean-burning fuels. The use of vegetable oil as an alternative fuel has for long been in the pipeline, but its direct use has been limited because of its higher viscosity. In this work, sunflower oil was taken as feedstock and the feasibility of sunflower oil methyl ester (SFME) as an alternative fuel for diesel engines was investigated. Tests were conducted in a 4.4 kW, single cylinder, naturally aspirated direct injection diesel engine. It was observed that the premixed combustion phase of SFME and its blends were less intense compared with diesel oil. In addition, it was observed that SFME and its blends had slightly lower thermal efficiency and lower tailpipe emissions than diesel oil.

G. Lakshmi Narayana Rao; S. Saravanan; P. Selva Ilavarasi; G. Devasagayam

2009-01-01T23:59:59.000Z

117

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

118

Laser ignition studies  

SciTech Connect

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

119

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...

120

Evaluation of oxides of nitrogen emissions for the purpose of their transient regulation from a direct injection diesel engine  

Science Journals Connector (OSTI)

The concept of defining a regulatory standard for the maximum allowable emissions of oxides of nitrogen (NOx) from a heavy-duty diesel engine on an instantaneous basis is presented. The significance of this concept from a regulatory point of view is the possibility to realise a steady brake specific NOx emissions result independent of the test schedule used. The emissions of oxides of nitrogen from a state-of-the-art direct injection diesel engine have been examined on an integral as well as on an instantaneous basis over the Federal Test Procedure as well as over several other arbitrary transient cycles generated for this study. Three candidate standards of specific NOx emissions have been evaluated on a real-time, continuous basis. These include brake power specific, fuel mass specific, and carbon dioxide mass specific NOx emissions. Retaining the stock engine control module, the carbon dioxide specific emissions of NOx have been shown to be the most uniform, varying only by about 30% of its mean value regardless of the test schedule or engine operation. The instantaneous fuel specific NOx emissions are shown to be relatively less invariant and the least steady are the brake power specific emissions with a coefficient of variation of up to 200%. Advancing injection timing has been shown to have a wide range of authority over the specific emissions of oxides of nitrogen regardless of the units used, when operating at full load in the vicinity of peak torque speeds. The carbon dioxide specific NOx emissions have shown a linear dependence on the power specific emissions, independent of the examined operating conditions. The trade-off between better brake thermal efficiency, lower exhaust gas temperature at advanced timing and lower NOx emissions has also been shown to be independent of the units of the specific standard used.

Yasser Yacoub; Chris Atkinson

2001-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ignition direct injection" 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

Performance and emission parameters optimization of mahua (Madhuca indica) based biodiesel in direct injection diesel engine using response surface methodology  

Science Journals Connector (OSTI)

Mahua oil ethyl ester was prepared from mahua oil using potassium hydroxide as catalyst by trans-esterification. The important fuel properties of mahua biodiesel blends were compared with those of high speed diesel and biodiesel standards. Variation of brake specific fuel consumption (BSFC) brake thermal efficiency (BTE) Pmax CO NOx hydrocarbons and smoke opacity across compression ratio blending ratio and load were studied successfully using response surface methodology based on Central composite rotatable design. The trends similar to general theory of compression ignition engines (CI) were obtained. Optimum performance and emission parameters were determined by considering the significant variables affecting the diesel engine. Significant reduction in emissions at 23% blending ratio were observed as compared to neat diesel at optimum input variables. Hence mahua biodiesel is an environment friendly alternate fuel over diesel and has good scope to run the compression ignition engines.

Sunil Dhingra; Gian Bhushan; Kashyap Kumar Dubey

2013-01-01T23:59:59.000Z

122

Polar-drive implosions on OMEGA and the National Ignition Facility P. B. Radha, F. J. Marshall, J. A. Marozas, A. Shvydky, I. Gabalski et al.  

E-Print Network (OSTI)

)1 permits direct-drive-ignition experi- ments on laser facilities like the National IgnitionPolar-drive implosions on OMEGA and the National Ignition Facility P. B. Radha, F. J. Marshall, J-drive implosions on OMEGA and the National Ignition Facilitya) P. B. Radha,1,b) F. J. Marshall,1 J. A. Marozas,1 A

123

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

124

National Ignition Facility & Photon Science  

NLE Websites -- All DOE Office Websites (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...

125

IGNITION IMPROVEMENT OF LEAN NATURAL GAS MIXTURES  

SciTech Connect

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

126

Effect of Fuel Injection Timing on the Emissions of a Direct-Injection (DI) Diesel Engine Fueled with Canola Oil Methyl Ester?Diesel Fuel Blends  

Science Journals Connector (OSTI)

(3, 4) A lot of researchers have reported that using biodiesel as a fuel in diesel engines causes a diminution in harmful exhaust emissions as well as equivalent engine performance with diesel fuel. ... Engine tests have been carried out with the aim of obtaining comparative measures of torque, power, specific fuel consumption and emissions such as CO, smoke d. and NOx to evaluate and compute the behavior of the diesel engine running on the above-mentioned fuels. ... Ma, Z.; Huang, Z. H.; Li, C.; Wang, X. B.; Miao, H.Effects of fuel injection timing on combustion and emission characteristics of a diesel engine fueled with diesel?propane blends Energy Fuels 2007, 21 ( 3) 1504– 1510 ...

Cenk Sayin; Metin Gumus; Mustafa Canakci

2010-03-11T23:59:59.000Z

127

Engines - Fuel Injection and Spray Research - Gasoline Sprays  

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

Gasoline Sprays Gasoline Sprays Animated image of fuel emerging from a gasoline injector Animated image of fuel emerging from a gasoline injector (simulated environment). Some newer automobiles in the U.S. use gasoline direct injection (GDI) engines. These advanced gasoline engines inject the fuel directly into the engine cylinder rather than into the intake port. These engines can achieve higher fuel efficiency, but they depend on a precise fuel/air mixture at the spark plug to initiate ignition. This leads to more stringent requirements on spray quality and reproducibility. GDI also enables new combustion strategies for gasoline engines such as lean burn engines that use less fuel and air. Lean burn engines may achieve efficiencies near those of diesels while producing low emissions. This

128

The effect of ethanol-water fumigation on the performance and emissions from a direct-injection diesel engine.  

E-Print Network (OSTI)

??The effect of ethanol fumigation and water injection on the performance and exhaust emissions from a 1.9-liter Volkswagen TDI diesel engine was investigated. The engine… (more)

Olson, André Louis

2010-01-01T23:59:59.000Z

129

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

130

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

NLE Websites -- All DOE Office Websites (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...

131

Central ignition scenarios for TFTR  

SciTech Connect

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

132

Effect of fuel injection strategies on the combustion process in a PFI boosted SI engine  

Science Journals Connector (OSTI)

A low-cost solution based on fuel injection strategies was investigated to optimize the combustion process in a boosted port fuel injection spark ignition (PFI SI) engine. The goal was to reduce the fuel consumption

S. S. Merola; P. Sementa; C. Tornatore…

2009-10-01T23:59:59.000Z

133

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

134

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

135

Frictionally induced ignition processes in drop and skid tests  

SciTech Connect

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

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

2010-01-01T23:59:59.000Z

136

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,...

137

Princeton Plasma Physics Lab - National Ignition Facility  

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

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

138

Direct Probing of Charge Injection and Polarization-Controlled Ionic Mobility on Ferroelectric LiNbO3 Surfaces  

SciTech Connect

Mapping surface potential with time-resolved Kelvin Probe Force Microscopy (tr-KPFM) in LiNbO3 periodically-poled single crystal revealed activation of the surface ionic subsystem. Electric fields higher than certain threshold value but lower than the switching field induce injection of charge from the biased electrode, formation of an active region in its vicinity and uneven distribution of screening charge on the opposite ferroelectric domains. Tr-KPFM technique allows investigating these phenomena in details.

Strelcov, Evgheni [ORNL] [ORNL; Ievlev, Dr. Anton [Ural State University, Russia] [Ural State University, Russia; Jesse, Stephen [ORNL] [ORNL; Kravchenko, Ivan I [ORNL] [ORNL; Shur, V.Y. [Institute of Physics and Applied Mathematics, Ural State University] [Institute of Physics and Applied Mathematics, Ural State University; Kalinin, Sergei V [ORNL] [ORNL

2014-01-01T23:59:59.000Z

139

Experimental Investigation of Fuel-Reactivity Controlled Compression Ignition (RCCI) Combustion Mode in a Multi-Cylinder, Light-Duty Diesel Engine  

SciTech Connect

An experimental study was performed to provide the combustion and emission characteristics resulting from fuel-reactivity controlled compression ignition (RCCI) combustion mode utilizing dual-fuel approach in a light-duty, multi-cylinder diesel engine. In-cylinder fuel blending using port fuel injection of gasoline before intake valve opening (IVO) and early-cycle, direct injection of diesel fuel was used as the charge preparation and fuel blending strategy. In order to achieve the desired auto-ignition quality through the stratification of the fuel-air equivalence ratio ( ), blends of commercially available gasoline and diesel fuel were used. Engine experiments were performed at an engine speed of 2300rpm and an engine load of 4.3bar brake mean effective pressure (BMEP). It was found that significant reduction in both nitrogen oxide (NOx) and particulate matter (PM) was realized successfully through the RCCI combustion mode even without applying exhaust gas recirculation (EGR). However, high carbon monoxide (CO) and hydrocarbon (HC) emissions were observed. The low combustion gas temperature during the expansion and exhaust processes seemed to be the dominant source of high CO emissions in the RCCI combustion mode. The high HC emissions during the RCCI combustion mode could be due to the increased combustion quenching layer thickness as well as the -stratification at the periphery of the combustion chamber. The slightly higher brake thermal efficiency (BTE) of the RCCI combustion mode was observed than the other combustion modes, such as the conventional diesel combustion (CDC) mode, and single-fuel, premixed charge compression ignition (PCCI) combustion mode. The parametric study of the RCCI combustion mode revealed that the combustion phasing and/or the peak cylinder pressure rise rate of the RCCI combustion mode could be controlled by several physical parameters premixed ratio (rp), intake swirl intensity, and start of injection (SOI) timing of directly injected fuel unlike other low temperature combustion (LTC) strategies.

Cho, Kukwon [ORNL] [ORNL; Curran, Scott [ORNL] [ORNL; Prikhodko, Vitaly Y [ORNL] [ORNL; Sluder, Scott [ORNL] [ORNL; Parks, II, James E [ORNL; Wagner, Robert M [ORNL] [ORNL

2011-01-01T23:59:59.000Z

140

Influence of Biodiesel Fuel on the Combustion and Emission Formation in a Direct Injection (DI) Diesel Engine  

Science Journals Connector (OSTI)

The injector needle lift trace at low engine speed was almost identical for both fuels, while at maximum engine speed, a shorter injection delay was observed for biodiesel fuel and the injector needle opened earlier as with D2 fuel. ... Figure 1 Comparison of the engine torque (M), fuel consumption (Gh), and brake specific energy consumption (ge) at full load for biodiesel fuel (BD) and D2 fuel in (a) TAM and (b) MAN engines. ... (7)?Sanatore, A.; Cardone, M.; Rocco, V.; Prati, M. V. A comparative analysis of combustion process in DI diesel engine fueled with biodiesel and diesel fuel. ...

Ales Hribernik; Breda Kegl

2007-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "ignition direct injection" 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

Plastic ablator ignition capsule design for the National Ignition Facility  

SciTech Connect

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

142

Comparison of PM emissions from a gasoline direct injected (GDI) vehicle and a port fuel injected (PFI) vehicle measured by electrical low pressure impactor (ELPI) with two fuels: Gasoline and M15 methanol gasoline  

Science Journals Connector (OSTI)

Two Euro 4 gasoline passenger vehicles (one gasoline direct injected vehicle and one port fuel injected vehicle) were tested over the cold start New European Driving Cycle (NEDC). Each vehicle was respectively fueled with gasoline and M15 methanol gasoline. Particle number concentrations were measured by the electrical low pressure impactor (ELPI). Particle masses were measured by gravimetric method and estimated from the number distributions using two density distributions (one is constant with the particle size and one is power law related with the size). The first 7 stages of ELPI were used for estimation. The results show that for each vehicle, PM masses measured by gravimetric method, the total PM numbers measured by ELPI and estimated PM masses for M15 are lower than those for gasoline. For each kind of fuel, PM masses by two methods and total PM numbers from the GDI vehicle are higher than those from the PFI one. PM number distribution curves of the four vehicle/fuel combinations are similar. All decline gradually and the maximum number of each curve occurs in the first stage. More than 99.9% numbers locate in the first 8 stages of which diameters are less than 1 ?m. PM number emissions correlate well with the acceleration of the two vehicles. The estimated particle masses were much lower than the gravimetric measurements.

Bin Liang; Yunshan Ge; Jianwei Tan; Xiukun Han; Liping Gao; Lijun Hao; Wentao Ye; Peipei Dai

2013-01-01T23:59:59.000Z

143

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

SciTech Connect

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

144

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

145

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

146

Analysis of an extremely fast valve opening camless system to improve transient performance in a turbocharged high speed direct injection diesel engine  

Science Journals Connector (OSTI)

This article describes a theoretical study on the performance optimisation of a high speed direct injection turbocharged diesel engine equipped with an electro-hydraulic variable valve actuation 'camless' system. This system provides extremely fast valve opening and closing slopes. Thus, its potential for recovering part of the energy lost in the valves by reducing gas flow sonic conditions in the valve throat has been investigated. This study has been mainly focused on the analysis of engine performance during a load transient evolution, but the full load steady state attained at the end of the load transient has been also discussed. The results of this investigation have confirmed important improvements in engine performance during the load transient owing to less energy being lost across the valves, which directly results in more energy being available in the turbine. This benefit has also been observed at full load steady state conditions.

J. Benajes; J.R. Serrano; V. Dolz; R. Novella

2009-01-01T23:59:59.000Z

147

Conceptual Design - Polar Drive Ignition Campaign  

SciTech Connect

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

Hansen, R

2012-04-05T23:59:59.000Z

148

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

149

Modeling the Effect of Fuel Ethanol Concentration on Cylinder Pressure Evolution in Direct-Injection Flex-Fuel Engines  

E-Print Network (OSTI)

Modeling the Effect of Fuel Ethanol Concentration on Cylinder Pressure Evolution in Direct the fuel vaporization pro- cess for ethanol-gasoline fuel blends and the associated charge cooling effect experimental cylinder pressure for different gasoline-ethanol blends and various speeds and loads on a 2.0 L

Stefanopoulou, Anna

150

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

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

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

151

National Ignition Campaign Hohlraum Energetics  

SciTech Connect

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

152

Study Reveals Fuel Injection Timing Impact on Particle Number Emissions (Fact Sheet)  

SciTech Connect

Start of injection can improve environmental performance of fuel-efficient gasoline direct injection engines.

Not Available

2012-12-01T23:59:59.000Z

153

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

SciTech Connect

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

154

An investigation of diesel–ignited propane dual fuel combustion in a heavy-duty diesel engine  

Science Journals Connector (OSTI)

Abstract This paper presents a detailed experimental analysis of diesel–ignited propane dual fuel combustion on a 12.9-l, six-cylinder, production heavy-duty diesel engine. Gaseous propane was fumigated upstream of the turbocharger air inlet and ignited using direct injection of diesel sprays. Results are presented for brake mean effective pressures (BMEP) from 5 to 20 bar and different percent energy substituted (PES) by propane at a constant engine speed of 1500 rpm. The effect of propane PES on apparent heat release rates, combustion phasing and duration, fuel conversion and combustion efficiencies, and engine-out emissions of oxides of nitrogen (NOx), smoke, carbon monoxide (CO), and total unburned hydrocarbons (HC) were investigated. Exhaust particle number concentrations and size distributions were also quantified for diesel–ignited propane combustion. With stock engine parameters, the maximum propane PES was limited to 86%, 60%, 33%, and 25% at 5, 10, 15, and 20 bar BMEPs, respectively, either by high maximum pressure rise rates (MPRR) or by excessive HC and CO emissions. With increasing PES, while fuel conversion efficiencies increased slightly at high \\{BMEPs\\} or decreased at low BMEPs, combustion efficiencies uniformly decreased. Also, with increasing PES, \\{NOx\\} and smoke emissions were generally decreased but these reductions were accompanied by higher HC and CO emissions. Exhaust particle number concentrations decreased with increasing PES at low loads but showed the opposite trends at higher loads. At 10 bar BMEP, by adopting a different fueling strategy, the maximum possible propane PES was extended to 80%. Finally, a limited diesel injection timing study was performed to identify the optimal operating conditions for the best efficiency-emissions-MPRR tradeoffs.

Andrew C. Polk; Chad D. Carpenter; Kalyan Kumar Srinivasan; Sundar Rajan Krishnan

2014-01-01T23:59:59.000Z

155

An investigation of high pressure/late cycle injection of CNG (compressed natural gas) as a fuel for rail applications  

SciTech Connect

This report describes a demonstration effort to investigate the use of natural gas in a medium-speed diesel engine. The effort was unique in the sense that natural gas was injected directly into the combustion chamber late in the compression stroke, as a high pressure gas rather than through low pressure fumigation or low pressure injection early in the compression stroke. Tests were performed on a laboratory two-cylinder, two-stroke cycle medium-speed diesel engine in an attempt to define its ability to operate on the high pressure/late cycle injection concept and to define the performance and emission characteristics of the engine under such operation. A small quantity of No.-2 diesel fuel was injected into the cylinder slightly before the gas injection to be used as an ignition source for the gas. Pilot (diesel fuel) and main (natural gas) timing and injection duration were systematically varied to optimize engine performance. The test demonstrated that the medium-speed engine was capable of attaining full rated speed and load (unlike the low pressure approach) with very low percentages of pilot injection with the absence of knock. Thermal efficiency was as much as 10 percent less than thermal efficiency levels obtained with neat diesel fuel. This was primarily due to the placement and injection characteristics of the pilot and main injectors. Optimization of the injection system would undoubtedly result in increased thermal efficiency. 11 figs., 4 tabs.

Wakenell, J.F.; O'Neal, G.G.; Baker, Q.A.; Urban, C.M.

1988-04-01T23:59:59.000Z

156

Transverse liquid fuel jet breakup, burning, and ignition  

SciTech Connect

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

157

Transverse liquid fuel jet breakup, burning, and ignition  

SciTech Connect

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

158

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

SciTech Connect

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

Moses, E

2011-03-25T23:59:59.000Z

159

THE AUTOIGNITION OF CYCLOPENTANE IN AN IGNITION QUALITY TESTER  

SciTech Connect

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

160

Diagnosing and controlling mix in National Ignition Facility implosion experiments  

SciTech Connect

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

Note: This page contains sample records for the topic "ignition direct injection" 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

WILDFIRE IGNITION RESISTANCE ESTIMATOR WIZARD SOFTWARE DEVELOPMENT REPORT  

SciTech Connect

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

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

2012-10-10T23:59:59.000Z

162

Ignition problems in scramjet testing  

SciTech Connect

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

163

Enhanced Model for Fast Ignition  

SciTech Connect

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

164

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

165

National Ignition Facility & Photon Science What  

NLE Websites -- All DOE Office Websites (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...

166

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

167

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

168

June 11, 1999: National Ignition Facility  

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

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

169

Heating National Ignition Facility, Realistic Financial Planning...  

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

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

170

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

171

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

172

Confinement of ignition and yield on the National Ignition Facility  

SciTech Connect

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

173

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

SciTech Connect

Shock ignition, a new concept for igniting thermonuclear fuel, offers the possibility for a near-term ({approx}3-4 years) test of high gain inertial confinement fusion on the National Ignition Facility at less than 1MJ drive energy and without the need for new laser hardware. In shock ignition, compressed fusion fuel is separately ignited by a strong spherically converging shock and, because capsule implosion velocities are significantly lower than those required for conventional hotpot ignition, fusion energy gains of {approx}60 may be achievable on NIF at laser drive energies around {approx}0.5MJ. Because of the simple all-DT target design, its in-flight robustness, the potential need for only 1D SSD beam smoothing, minimal early time LPI preheat, and use of present (indirect drive) laser hardware, this target may be easier to field on NIF than a conventional (polar) direct drive hotspot ignition target. Like fast ignition, shock ignition has the potential for high fusion yields at low drive energy, but requires only a single laser with less demanding timing and spatial focusing requirements. Of course, conventional symmetry and stability constraints still apply. In this paper we present initial target performance simulations, delineate the critical issues and describe the immediate-term R&D program that must be performed in order to test the potential of a high gain shock ignition target on NIF in the near term.

Perkins, L J; Betti, R; Schurtz, G P; Craxton, R S; Dunne, A M; LaFortune, K N; Schmitt, A J; McKenty, P W; Bailey, D S; Lambert, M A; Ribeyre, X; Theobald, W R; Strozzi, D J; Harding, D R; Casner, A; Atzemi, S; Erbert, G V; Andersen, K S; Murakami, M; Comley, A J; Cook, R C; Stephens, R B

2010-04-12T23:59:59.000Z

174

Direct  

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

interactions, and the pollutant emission is hence directly proportional to the bulk neutral density. Simultaneously monitoring the total emission at 1040 nm and the...

175

Effects of Bioethanol-Blended Diesel Fuel on Combustion and Emission Reduction Characteristics in a Direct-Injection Diesel Engine with Exhaust Gas Recirculation (EGR)  

Science Journals Connector (OSTI)

Department of Mechanical Engineering, Hanyang University, 17 Haengdang-dong, Sungdong-gu, Seoul 133-791, Korea ... As a fuel for compression engines, bioethanol-blended diesel fuels have some different trends on the exhaust emission characteristics according to the engine load. ... The paper begins with an introduction of general information on the nature of emissions of exhaust gases, including the toxicity and causes of emissions for both spark-ignition and diesel engines. ...

Su Han Park; Junepyo Cha; Chang Sik Lee

2010-06-03T23:59:59.000Z

176

The effects of unburned hydrocarbon recirculation on ignition and combustion during diesel engine cold starts  

Science Journals Connector (OSTI)

Abstract The exhaust gases contain large amounts of unburned hydrocarbons during cranking without combustion. The effects of unburned hydrocarbon recirculation on ignition and combustion during diesel engine cold starts were investigated using both experiments and simulations. Experiments were conducted on a single-cylinder DI (direct injection) diesel engine equipped with a common rail injection system. The amount of unburned hydrocarbon recirculation was jointly controlled by an EGR (exhaust gas recirculation) valve and a back pressure valve. The investigation showed that optimal opening of recirculation control valves allowed the first firing cycle to be advanced from 19 to 6 and reduced the duration of heavy smoke emission (opacity > 50%) by 77%. However, the enhancement to the in-cylinder LTR (low temperature reaction) decreased gradually as the amount of unburned hydrocarbon recirculation increased. An analysis of the chemical kinetics showed that the reaction intermediates present in unburned hydrocarbons, such as ketohydroperoxides, were the most significant factor in enhancing the LTR during non-firing cycles. At the same time, the substantial heat capacity of unburned hydrocarbons suppressed the LTR for higher recirculation rates.

Yi Cui; Haiyong Peng; Kangyao Deng; Lei Shi

2014-01-01T23:59:59.000Z

177

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

SciTech Connect

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

178

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

SciTech Connect

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

179

Comparison of Neat Biodiesels and ULSD in an Optimized Single-Cylinder Diesel Engine with Electronically-Controlled Fuel Injection  

Science Journals Connector (OSTI)

An Experimental Investigation of the Origin of Increased NOx Emissions When Fueling a Heavy-Duty Compression-Ignition Engine with Soy Biodiesel SAE Int. ... The fuels were then burned in a single-cylinder direct-injection diesel engine and evaluated for both fuel consumption and exhaust emissions of nitrogen oxides, carbon monoxide (CO), unburned hydrocarbons, and particulate matter. ... Monyem, A.; Van Gerpen, J.; Canakcl, M.The effect of timing and oxidation on emissions from biodiesel–fueled engines Carbon 2001, 44 ( 1) 35– 42 ...

Michael Mangus; Farshid Kiani; Jonathan Mattson; Christopher Depcik; Edward Peltier; Susan Stagg-Williams

2014-05-12T23:59:59.000Z

180

Experimental investigation of the effect of combined hydrogen and diesel combustion on the particulate size distribution from a high speed direct injection diesel engine  

Science Journals Connector (OSTI)

The effects of hydrogen addition and exhaust gas recirculation (EGR) levels on the exhaust particulate matter size distribution in a diesel engine have been investigated. The experiments were performed on a 2.0 litre, 4-cylinder, direct injection engine equipped with a modern high-pressure common rail. A nano-Micro-Orifice Uniform Deposit Impactor (nano-MOUDI) was used in this work to study the particulate matter size distribution. All tests were conducted at the set operating point of 1,500 rpm. The experimental work showed that the particulate matter size distribution was not dramatically altered by the addition of EGR, but the main peak was shifted towards the nucleation mode with the addition of hydrogen. The addition of hydrogen increases the emissions of nitrogen oxides (NOx), but reduces the emissions of unburnt hydrocarbons (THC). Conversely, the addition of EGR reduces NOx, but can increase THC. Hydrogen addition increases the peak cylinder pressure and the maximum rate of pressure rise.

L. McWilliam; A. Megaritis

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ignition direct injection" 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

Artificial neural networks based prediction of performance and exhaust emissions in direct injection engine using castor oil biodiesel-diesel blends  

Science Journals Connector (OSTI)

In this study the performance and emission characteristics of a direct injection diesel engine using castor oil biodiesel (COB)-diesel blended fuels were investigated experimentally and then predicted by artificial neural networks. For this aim castor oil was converted to its biodiesel via transesterification approach. Then the effects of the biodiesel percentage in blend engine load and speed on brake power brake specific fuel consumption (BSFC) nitrogen oxides (NOx) carbon dioxide (CO2) carbon monoxide (CO) and particle matter (PM) have been considered. Fuel blends with various percentages of biodiesel (0% 5% 10% 15% 20% 25% and 30%) at various engine speeds and loads were tested. The results indicated that blends of COB with diesel fuel provide admissible engine performance; on the other side emissions decreased so much. Two types of neural networks a group method of data handling (GMDH) and feed forward were used for modeling of the diesel engine to predict brake power BSFC and exhaust emissions such as CO CO2 NOx and PM values. The comparison results demonstrate the superiority of the feed forward neural networkmodels over GMDH type models in terms of the statistical measures in the training and testing data but in the number of hidden neurons and model simplicity GMDH models are preferred.

M. H. Shojaeefard; M. M. Etghani; M. Akbari; A. Khalkhali; B. Ghobadian

2012-01-01T23:59:59.000Z

182

Effect of palm methyl ester-diesel blends performance and emission of a single-cylinder direct-injection diesel engine  

Science Journals Connector (OSTI)

The purpose of this study is to investigate engine performance and exhaust emission when using several blends of neat palm oil methyl ester (POME) with conventional diesel (D2) in a small direct injection diesel engine and to compare the outcomes to that of the D2 fuel. Engine performances exhaust emissions and some other important parameters were observed as a function of engine load and speed. In addition the effect of modifying compression ratio was also carried out in this study. From the engine experimental work neat and blended fuels behaved comparably to diesel (D2) in terms of fuel consumption thermal efficiency and rate of heat released. Smoke density showed better results than that emitted by D2 operating under similar conditions due to the presence of inherited oxygen and lower sulphur content in the biofuel and its blends. The emissions of CO CO2 and HC were also lower using blended mixtures and in its neat form. However NOx concentrations were found to be slight higher for POME and its blends and this was largely due to higher viscosity of POME and possibly the presence of nitrogen in the palm methyl ester. General observation indicates that biofuel blends can be use without many difficulties in this type of engine but for optimized operation minor modifications to the engine and its auxiliaries are required.

Mazlan Said; Azhar Abdul Aziz

2012-01-01T23:59:59.000Z

183

Progress Toward Ignition on the National Ignition Facility  

SciTech Connect

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

Kauffman, R L

2011-10-17T23:59:59.000Z

184

Modeling of homogeneous charge compression ignition (HCCI) of methane  

SciTech Connect

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

185

Diagnostics for Fast Ignition Science  

SciTech Connect

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

186

DRIVE CYCLE EFFICIENCY AND EMISSIONS ESTIMATES FOR REACTIVITY CONTROLLED COMPRESSION IGNITION IN A MULTI-CYLINDER LIGHT-DUTY DIESEL ENGINE  

SciTech Connect

In-cylinder blending of gasoline and diesel to achieve Reactivity Controlled Compression Ignition (RCCI) has been shown to reduce NOx and PM emissions while maintaining or improving brake thermal efficiency as compared to conventional diesel combustion (CDC). The RCCI concept has an advantage over many advanced combustion strategies in that by varying both the percent of premixed gasoline and EGR rate, stable combustion can be extended over more of the light-duty drive cycle load range. Changing the percent premixed gasoline changes the fuel reactivity stratification in the cylinder providing further control of combustion phasing and pressure rise rate than the use of EGR alone. This paper examines the combustion and emissions performance of light-duty diesel engine using direct injected diesel fuel and port injected gasoline to carry out RCCI for steady-state engine conditions which are consistent with a light-duty drive cycle. A GM 1.9L four-cylinder engine with the stock compression ratio of 17.5:1, common rail diesel injection system, high-pressure EGR system and variable geometry turbocharger was modified to allow for port fuel injection with gasoline. Engine-out emissions, engine performance and combustion behavior for RCCI operation is compared against both CDC and a premixed charge compression ignition (PCCI) strategy which relies on high levels of EGR dilution. The effect of percent of premixed gasoline, EGR rate, boost level, intake mixture temperature, combustion phasing and pressure rise rate is investigated for RCCI combustion for the light-duty modal points. Engine-out emissions of NOx and PM were found to be considerably lower for RCCI operation as compared to CDC and PCCI, while HC and CO emissions were higher. Brake thermal efficiency was similar or higher for many of the modal conditions for RCCI operation. The emissions results are used to estimate hot-start FTP-75 emissions levels with RCCI and are compared against CDC and PCCI modes.

Curran, Scott [ORNL; Briggs, Thomas E [ORNL; Cho, Kukwon [ORNL; Wagner, Robert M [ORNL

2011-01-01T23:59:59.000Z

187

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

188

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

DOE Patents (OSTI)

A method for slowing the heat-release rate in homogeneous charge compression ignition ("HCCI") engines that allows operation without excessive knock at higher engine loads than are possible with conventional HCCI. This method comprises injecting a fuel charge in a manner that creates a stratified fuel charge in the engine cylinder to provide a range of fuel concentrations in the in-cylinder gases (typically with enough oxygen for complete combustion) using a fuel with two-stage ignition fuel having appropriate cool-flame chemistry so that regions of different fuel concentrations autoignite sequentially.

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

2006-10-31T23:59:59.000Z

189

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

SciTech Connect

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

190

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

191

Laser Spark Distribution and Ignition System  

NLE Websites -- All DOE Office Websites (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...

192

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...

193

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

194

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

195

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

196

National Ignition Facility | National Nuclear Security Administration  

NLE Websites -- All DOE Office Websites (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...

197

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

198

Numerical study on the combustion and emission characteristics of a methanol/diesel reactivity controlled compression ignition (RCCI) engine  

Science Journals Connector (OSTI)

An improved multi-dimensional model coupled with detailed chemical kinetics mechanism was applied to investigate the combustion and emission characteristics of a methanol/diesel reactivity controlled compression ignition (RCCI) engine. The fuel was supplied separately by directly injecting diesel fuel into cylinder well before top dead center, while premixing methanol through the intake port in the tested methanol/diesel RCCI engine. The effects of mass fraction of premixed methanol, start of injection (SOI) of diesel and initial in-cylinder temperature at intake valve closing (IVC) on engine combustion and emission were investigated in detail. The results show that both methanol mass fraction and SOI have a significant impact on cetane number (CN) distribution, i.e. fuel reactivity distribution, which determines the ignition delay and peak of heat release rate (HRR). Due to larger area with high-temperature region and more homogeneous fuel distribution with increased methanol, and the oxygen atom contained by methanol molecule, all the emissions are reduced with moderate methanol addition. Advanced SOI with high combustion temperature is favorable to hydrocarbon (HC) and soot reduction, yet not to the decrease of nitrogen oxide (NOx) and carbon monoxide (CO) emissions. Both increasing methanol fraction and advancing the SOI are beneficial to improve fuel economy and avoid engine knock. Moreover, it was revealed that the initial temperature must be increased with increased methanol fraction to keep the 50% burn point (CA50) constant, which results in decrease of the equivalent indicated specific fuel consumption (EISFC) and all emissions, except for slight increase in \\{NOx\\} due to the higher burning temperature.

Yaopeng Li; Ming Jia; Yaodong Liu; Maozhao Xie

2013-01-01T23:59:59.000Z

199

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

200

Experimental investigations of the performance, emission and combustion characteristics of a biodiesel (ethyl ester of fish oil) fuelled direct-injection diesel engine  

Science Journals Connector (OSTI)

The thirst for fuel is steadily increasing as technology continues to open new areas of exploration. At the same time, the indiscriminate extraction of fossil fuels may also result in pollutant emissions which cause major impacts on ecological systems. In order to overcome the above problems, a suitable biodiesel should be used to replace the diesel fuel. Hence, in this work, feasibility of using biodiesel prepared from fish oil was investigated. Experimental tests were carried out to evaluate the performance, emission and combustion characteristics of a single cylinder, constant speed engine using several blends under variable load conditions. It was found that NOx, HC and CO emission was reduced for blends along with a marginal increase of brake thermal efficiency and smoke. The ignition delay and maximum heat release rate were reduced compared to diesel. Ultimately, fish oil can indeed become the appropriate source for biodiesel with environmental benefits.

G. Sakthivel; G. Nagarajan; M. Ilangkumaran

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ignition direct injection" 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

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

SciTech Connect

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

202

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

SciTech Connect

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

203

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,...

204

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...

205

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,...

206

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

207

AISI/DOE Technology Roadmap Program Hot Oxygen Injection Into The Blast Furnace  

SciTech Connect

Increased levels of blast furnace coal injection are needed to further lower coke requirements and provide more flexibility in furnace productivity. The direct injection of high temperature oxygen with coal in the blast furnace blowpipe and tuyere offers better coal dispersion at high local oxygen concentrations, optimizing the use of oxygen in the blast furnace. Based on pilot scale tests, coal injection can be increased by 75 pounds per ton of hot metal (lb/thm), yielding net savings of $0.84/tm. Potential productivity increases of 15 percent would yield another $1.95/thm. In this project, commercial-scale hot oxygen injection from a ''thermal nozzle'' system, patented by Praxair, Inc., has been developed, integrated into, and demonstrated on two tuyeres of the U.S. Steel Gary Works no. 6 blast furnace. The goals were to evaluate heat load on furnace components from hot oxygen injection, demonstrate a safe and reliable lance and flow control design, and qualitatively observe hot oxygen-coal interaction. All three goals have been successfully met. Heat load on the blowpipe is essentially unchanged with hot oxygen. Total heat load on the tuyere increases about 10% and heat load on the tuyere tip increases about 50%. Bosh temperatures remained within the usual operating range. Performance in all these areas is acceptable. Lance performance was improved during testing by changes to lance materials and operating practices. The lance fuel tip was changed from copper to a nickel alloy to eliminate oxidation problems that severely limited tip life. Ignition flow rates and oxygen-fuel ratios were changed to counter the effects of blowpipe pressure fluctuations caused by natural resonance and by coal/coke combustion in the tuyere and raceway. Lances can now be reliably ignited using the hot blast as the ignition source. Blowpipe pressures were analyzed to evaluate ht oxygen-coal interactions. The data suggest that hot oxygen increases coal combustion in the blow pipe and tuyere by 30, in line with pilot scale tests conducted previously.

Michael F. Riley

2002-10-21T23:59:59.000Z

208

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

SciTech Connect

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

209

Testing of a Continuous Detonation Wave Engine with Swirled Injection  

E-Print Network (OSTI)

Testing of a Continuous Detonation Wave Engine with Swirled Injection Eric M. Braun Nathan L. Dunn detonation wave engines with swirl to improve mixing were developed. The reactants were ignited with an ordinary automotive spark plug. Mixing and detonation occurred in a common annular chamber in the first

Texas at Arlington, University of

210

Injection-Induced Earthquakes  

Science Journals Connector (OSTI)

...sounds safe enough. But if the deep aquifer system was originally underpressured...directed toward protection of potable aquifers by requiring injection into formations...much smaller magnitudes. The largest fracking-induced earthquakes (24, 26) have all been below the damage...

William L. Ellsworth

2013-07-12T23:59:59.000Z

211

Tevatron injection timing  

SciTech Connect

Bunched beam transfer from one accelerator to another requires coordination and synchronization of many ramped devices. During collider operation timing issues are more complicated since one has to switch from proton injection devices to antiproton injection devices. Proton and antiproton transfers are clearly distinct sequences since protons and antiprotons circulate in opposite directions in the Main Ring (MR) and in the Tevatron. The time bumps are different, the kicker firing delays are different, the kickers and lambertson magnets are different, etc. Antiprotons are too precious to be used for tuning purposes, therefore protons are transferred from the Tevatron back into the Main Ring, tracing the path of antiprotons backwards. This tuning operation is called ``reverse injection.`` Previously, the reverse injection was handled in one supercycle. One batch of uncoalesced bunches was injected into the Tevatron and ejected after 40 seconds. Then the orbit closure was performed in the MR. In the new scheme the lambertson magnets have to be moved and separator polarities have to be switched, activities that cannot be completed in one supercycle. Therefore, the reverse injection sequence was changed. This involved the redefinition of TVBS clock event $D8 as MRBS $D8 thus making it possible to inject 6 proton batches (or coalesced bunches) and eject them one at a time on command, performing orbit closure each time in the MR. Injection devices are clock event driven. The TCLK is used as the reference clock. Certain TCLK events are triggered by the MR beam synchronized clock (MRBS) events. Some delays are measured in terms of MRBS ticks and MR revolutions. See Appendix A for a brief description of the beam synchronized clocks.

Saritepe, S.; Annala, G.

1993-06-01T23:59:59.000Z

212

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

213

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

SciTech Connect

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

214

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

215

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

216

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

217

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

218

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

219

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

220

Laser Spark Distribution and Ignition System  

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

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

Note: This page contains sample records for the topic "ignition direct injection" 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

Confinement scaling and ignition in tokamaks  

SciTech Connect

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

222

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

223

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

224

Effects of diesel injection pressure on the performance and emissions of a HD common-rail diesel engine fueled with diesel/methanol dual fuel  

Science Journals Connector (OSTI)

Abstract The diesel/methanol dual fuel (DMDF) combustion mode was conducted on a turbo-charged, inter-cooling diesel engine with 6-cylinder for the heavy duty (HD) vehicle. In DMDF mode, methanol is injected into the intake port to form lean air/methanol premixed mixture, and then ignited by the direct-injected diesel fuel in cylinder. This study is aimed to investigate the effect of diesel injection pressure on the characteristics of performance and exhaust emissions from the engine with common-rail fuel system. The experimental results show that at low injection pressure, the IMEP of DMDF mode is lower than that of pure diesel combustion (D) mode. COVIEMP of DMDF mode firstly decreases and then increases with increasing injection pressure, and it remains under 2.1% for all the tests. It is found that the combustion duration in DMDF mode becomes shorter, the maximum cylinder pressure and the peak heat release rate increase, and CA50 gets close to the top dead center as the injection pressure increases. BSFC of DMDF mode decreases with the increase of injection pressure, and is lower than that of D mode for injection pressure over 115 MPa. Both of NOX and smoke emissions are reduced in DMDF mode. But smoke decreases and NOX increases as the diesel injection pressure increases in DMDF mode. DMDF generates lower NO and CO2 emissions, while produces higher HC, CO, andNO2 emissions compared to D mode. As the diesel injection pressure increases, CO and HC emissions are decreased, however, CO2 and NO2 emissions are slightly increased.

Junheng Liu; Anren Yao; Chunde Yao

2015-01-01T23:59:59.000Z

225

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

226

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

SciTech Connect

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

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

2012-09-15T23:59:59.000Z

227

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

228

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

229

Chemical Kinetics of Hydrocarbon Ignition in Practical Combustion Systems  

SciTech Connect

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

230

Analytical model for fast-shock ignition  

SciTech Connect

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

231

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

232

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

233

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

234

National Ignition Facility & Photon Science NIF AT A GLANCe  

NLE Websites -- All DOE Office Websites (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...

235

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

236

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

237

National Ignition Facility & Photon Science NIF Fun Facts  

NLE Websites -- All DOE Office Websites (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,...

238

Target Visualization at the National Ignition Facility  

SciTech Connect

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

Potter, D

2011-11-21T23:59:59.000Z

239

The velocity campaign for ignition on NIF  

SciTech Connect

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

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

2012-05-15T23:59:59.000Z

240

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

Note: This page contains sample records for the topic "ignition direct injection" 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

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...

242

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

243

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

244

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

245

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

SciTech Connect

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

246

Superheated fuel injection for combustion of liquid-solid slurries  

DOE Patents (OSTI)

A method and device are claimed for obtaining, upon injection, flash evaporation of a liquid in a slurry fuel to aid in ignition and combustion. The device is particularly beneficial for use of coal-water slurry fuels in internal combustion engines such as diesel engines and gas turbines, and in external combustion devices such as boilers and furnaces. The slurry fuel is heated under pressure to near critical temperature in an injector accumulator, where the pressure is sufficiently high to prevent boiling. After injection into a combustion chamber, the water temperature will be well above boiling point at a reduced pressure in the combustion chamber, and flash boiling will preferentially take place at solid-liquid surfaces, resulting in the shattering of water droplets and the subsequent separation of the water from coal particles. This prevents the agglomeration of the coal particles during the subsequent ignition and combustion process, and reduces the energy required to evaporate the water and to heat the coal particles to ignition temperature. The overall effect will be to accelerate the ignition and combustion rates, and to reduce the size of the ash particles formed from the coal. 2 figs., 2 tabs.

Robben, F.A.

1984-10-19T23:59:59.000Z

247

Load expansion of naphtha multiple premixed compression ignition (MPCI) and comparison with partially premixed compression ignition (PPCI) and conventional diesel combustion (CDC)  

Science Journals Connector (OSTI)

Abstract In previous studies, multiple premixed compression ignition (MPCI) has been proposed as a novel combustion concept in gasoline compression ignition engines which has great potential to achieve high thermal efficiency and low emissions simultaneously. MPCI mode was realized by a sequence of “spray–combustion–spray–combustion” around the compression top dead center (TDC). This study is aimed for the high load expansion of naphtha MPCI. In addition, the study investigated advantages and disadvantages of MPCI compared with partially premixed compression ignition (PPCI) and conventional diesel combustion (CDC). Engine operating range successfully reached indicated mean effective pressure (IMEP) of 1.4 MPa with high thermal efficiency, low emissions and acceptable combustion noise by the optimization of the injection parameters and the intake management. For MPCI, earlier combustion phasing was possible even at the high load operation compared with PPCI and CDC. This was attributed to the separated heat release characteristics and pressure rise rate process. The divided pressure rise rate process caused considerably low maximum pressure rise rate (MPRR) characteristics such as 0.8 MPa/deg at IMEP 1.4 MPa condition. The earlier combustion phasing led to the higher thermal efficiency characteristics of MPCI combustion compared with PPCI and CDC. This was attributed to the lower exhaust heat loss characteristics. However, high level of hydrocarbon (HC) and carbon monoxide (CO) emissions with low combustion stability at the low load operation were considered as severe challenges to overcome.

Kihyun Kim; Zhi Wang; Buyu Wang; Shijin Shuai; Hongqiang Yang; Choongsik Bae

2014-01-01T23:59:59.000Z

248

The National Ignition Facility and the Promise of Inertial Fusion Energy  

SciTech Connect

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

249

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

250

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

251

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

252

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

253

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

254

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

255

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

256

Implosion dynamics measurements at the National Ignition Facility  

SciTech Connect

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

257

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

SciTech Connect

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

258

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

SciTech Connect

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

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

2012-11-15T23:59:59.000Z

259

Target diagnostic system for the national ignition facility (invited)  

SciTech Connect

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

260

Ignition and extinction phenomena in helium micro hollow cathode discharges  

SciTech Connect

Micro hollow cathode discharges (MHCD) were produced using 250??m thick dielectric layer of alumina sandwiched between two nickel electrodes of 8??m thickness. A through cavity at the center of the chip was formed by laser drilling technique. MHCD with a diameter of few hundreds of micrometers allowed us to generate direct current discharges in helium at up to atmospheric pressure. A slowly varying ramped voltage generator was used to study the ignition and the extinction periods of the microdischarges. The analysis was performed by using electrical characterisation of the V-I behaviour and the measurement of He*({sup 3}S{sub 1}) metastable atoms density by tunable diode laser spectroscopy. At the ignition of the microdischarges, 2??s long current peak as high as 24?mA was observed, sometimes followed by low amplitude damped oscillations. At helium pressure above 400?Torr, an oscillatory behaviour of the discharge current was observed just before the extinction of the microdischarges. The same type of instability in the extinction period at high pressure also appeared on the density of He*({sup 3}S{sub 1}) metastable atoms, but delayed by a few ?s relative to the current oscillations. Metastable atoms thus cannot be at the origin of the generation of the observed instabilities.

Kulsreshath, M. K.; Schwaederle, L.; Dufour, T.; Lefaucheux, P.; Dussart, R. [GREMI, CNRS/Université d'Orléans (UMR7344), Orléans (France); Sadeghi, N. [LIPhy, CNRS and Universite Joseph Fourier (UMR5588), Grenoble (France); Overzet, L. J. [GREMI, CNRS/Université d'Orléans (UMR7344), Orléans (France); PSAL, UTDallas, Richardson, Texas 75080-3021 (United States)

2013-12-28T23:59:59.000Z

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


261

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

SciTech Connect

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

262

National Ignition Facility Title II Design Plan  

SciTech Connect

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

263

Impacts assessment for the National Ignition Facility  

SciTech Connect

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

264

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

265

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

266

Advanced aircraft ignition CRADA final report  

SciTech Connect

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

267

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

268

Groundbreaking at National Ignition Facility | National Nuclear Security  

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

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

269

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

SciTech Connect

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

270

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

SciTech Connect

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

271

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

SciTech Connect

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

272

A study of ignition of oil shale and char  

SciTech Connect

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

273

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

SciTech Connect

The National Ignition Facility (NIF), the world's largest and most powerful laser system for inertial confinement fusion (ICF) and experiments studying high-energy-density (HED) science, is now operational at Lawrence Livermore National Laboratory (LLNL). NIF construction was certified by the Department of Energy as complete on March 27, 2009. NIF, a 192-beam Nd:glass laser facility, will ultimately produce 1.8-MJ, 500-TW of 351-nm third-harmonic, ultraviolet light. On March 10, 2009, total 192-beam energy of 1.1 MJ was demonstrated; this is approximately 30 times more energy than ever produced in an ICF laser system. The principal goal of NIF is to achieve ignition of a deuterium-tritium (DT) fuel capsule and provide access to HED physics regimes needed for experiments related to national security, fusion energy and broader frontier scientific exploration. NIF experiments in support of indirect-drive ignition began in August 2009. These first experiments represent the next phase of the National Ignition Campaign (NIC). The NIC is a national effort to achieve fusion ignition and is coordinated through a detailed execution plan that includes the science, technology, and equipment. Equipment required for ignition experiments includes diagnostics, a cryogenic target manipulator, and user optics. Participants in this effort include LLNL, General Atomics (GA), Los Alamos National Laboratory (LANL), Sandia National Laboratory (SNL), and the University of Rochester Laboratory for Energetics (LLE). The primary goal for NIC is to have all of the equipment operational, integrated into the facility, and ready to begin a credible ignition campaign in 2010. With NIF now operational, the long-sought goal of achieving self-sustained nuclear fusion and energy gain in the laboratory is much closer to realization. Successful demonstration of ignition and net energy gain on NIF will be a major step towards demonstrating the feasibility of Inertial Fusion Energy (IFE) and will likely focus the world's attention on the possibility of an ICF energy option. NIF experiments to demonstrate ignition and gain will use central-hot-spot (CHS) ignition, where a spherical fuel capsule is simultaneously compressed and ignited. The scientific basis for CHS has been intensively developed. Achieving ignition with CHS will open the door for other advanced concepts, such as the use of high-yield pulses of visible wavelength rather than ultraviolet and Fast Ignition concepts. Moreover, NIF will have important scientific applications in such diverse fields as astrophysics, nuclear physics and materials science. The NIC will develop the full set of capabilities required to operate NIF as a major national and international user facility. A solicitation for NIF frontier science experiments is planned for summer 2009. This paper summarizes the design, performance, and status of NIF and plans for the NIF ignition experimental program. A brief summary of the overall NIF experimental program is also presented.

Moses, E

2009-09-17T23:59:59.000Z

274

Two stroke homogenous charge compression ignition engine with pulsed air supplier  

DOE Patents (OSTI)

A two stroke homogenous charge compression ignition engine includes a volume pulsed air supplier, such as a piston driven pump, for efficient scavenging. The usage of a homogenous charge tends to decrease emissions. The use of a volume pulsed air supplier in conjunction with conventional poppet type intake and exhaust valves results in a relatively efficient scavenging mode for the engine. The engine preferably includes features that permit valving event timing, air pulse event timing and injection event timing to be varied relative to engine crankshaft angle. The principle use of the invention lies in improving diesel engines.

Clarke, John M. (Chillicothe, IL)

2003-08-05T23:59:59.000Z

275

National ignition facility environment, safety, and health management plan  

SciTech Connect

The ES&H Management Plan describes all of the environmental, safety, and health evaluations and reviews that must be carried out in support of the implementation of the National Ignition Facility (NIF) Project. It describes the policy, organizational responsibilities and interfaces, activities, and ES&H documents that will be prepared by the Laboratory Project Office for the DOE. The only activity not described is the preparation of the NIF Project Specific Assessment (PSA), which is to be incorporated into the Programmatic Environmental Impact Statement for Stockpile Stewardship and Management (PEIS). This PSA is being prepared by Argonne National Laboratory (ANL) with input from the Laboratory participants. As the independent NEPA document preparers ANL is directly contracted by the DOE, and its deliverables and schedule are agreed to separately with DOE/OAK.

NONE

1995-11-01T23:59:59.000Z

276

Flame propagation and counterflow nonpremixed ignition of mixtures of methane and ethylene  

SciTech Connect

The ignition temperature of nitrogen-diluted mixtures of methane and ethylene counterflowing against heated air was measured up to five atmospheres. In addition, the stretch-corrected laminar flame speeds of mixtures of air, methane and ethylene were determined from outwardly-propagating spherical flames up to 10 atmospheres, for extensive range of the lean-to-rich equivalence ratio. These experimental data, relevant to low- to moderately-high-temperature ignition chemistry and high-temperature flame chemistry, respectively, were subsequently compared with calculations using two detailed kinetic mechanisms. A chemical explosive mode analysis (CEMA) was then conducted to identify the dominant ignition chemistry and the role of ethylene addition in facilitating nonpremixed ignition. Furthermore, the hierarchical structure of the associated oxidation kinetics was examined by comparing the sizes and constituents of the skeletal mechanisms of the pure fuels and their mixtures, derived using the method of directed relation graph (DRG). The skeletal mechanism was further reduced by time-scale analysis, leading to a 24-species reduced mechanism from the detailed mechanism of USC Mech II, validated within the parameter space of the conducted experiments. (author)

Liu, W.; Kelley, A.P.; Law, C.K. [Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08544 (United States)

2010-05-15T23:59:59.000Z

277

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

SciTech Connect

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

Ma, T

2010-04-21T23:59:59.000Z

278

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

279

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

280

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

Note: This page contains sample records for the topic "ignition direct injection" 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

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

282

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

283

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

284

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

285

Relationship between ignition processes and the lift-off length of diesel fuel jets.  

SciTech Connect

The reaction zone of a diesel fuel jet stabilizes at a location downstream of the fuel injector once the initial autoignition phase is over. This distance is referred to as flame lift-off length. Recent investigations have examined the effects of a wide range of parameters (injection pressure, orifice diameter, and ambient gas temperature, density and oxygen concentration) on lift-off length under quiescent diesel conditions. Many of the experimental trends in lift-off length were in agreement with scaling laws developed for turbulent, premixed flame propagation in gas-jet lifted flames at atmospheric conditions. However, several effects did not correlate with the gas-jet scaling laws, suggesting that other mechanisms could be important to lift-off stabilization at diesel conditions. This paper shows experimental evidence that ignition processes affect diesel lift-off stabilization. Experiments were performed in the same optically-accessible combustion vessel as the previous lift-off research. The experimental results show that the ignition quality of a fuel affects lift-off. Fuels with shorter ignition delays generally produce shorter lift-off lengths. In addition, a cool flame is found upstream of, or near the same axial location as, the quasi-steady lift-off length, indicating that first-stage ignition processes affect lift-off. High-speed chemiluminescence imaging also shows that high-temperature self-ignition occasionally occurs in kernels that are upstream of, and detached from, the high-temperature reaction zone downstream, suggesting that the lift-off stabilization is not by flame propagation into upstream reactants in this instance. Finally, analysis of the previous lift-off length database shows that the time-scale for jet mixing from injector-tip orifice to lift-off length collapses to an Arrhenius-type expression, a common method for describing ignition delay in diesel sprays. This Arrhenius-based lift-off length correlation shows comparable accuracy as a previous power-law fit of the No.2 diesel lift-off length database.

Siebers, Dennis L.; Idicheria, Cherian A.; Pickett, Lyle M.

2005-06-01T23:59:59.000Z

286

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

287

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

288

Capsule performance optimization in the National Ignition Campaign  

SciTech Connect

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

289

Capsule Performance Optimization in the National Ignition Campaign  

SciTech Connect

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

290

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

SciTech Connect

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

291

A Concept Exploration Program in Fast Ignition Inertial Fusion — Final Report  

SciTech Connect

The Fast Ignition (FI) approach to Inertial Confinement Fusion (ICF) holds particular promise for fusion energy because the independently generated compression and ignition pulses allow ignition with less compression, resulting in (potentially) higher gain. Exploiting this concept effectively requires an understanding of the transport of electrons in prototypical geometries and at relevant densities and temperatures. Our consortium, which included General Atomics (GA), The Ohio State University (OSU), the University of California, San Diego (UCSD), University of California, Davis (UC-Davis), and Princeton University under this grant (~$850K/yr) and Lawrence Livermore National Laboratory (LLNL) under a companion grant, won awards in 2000, renewed in 2005, to investigate the physics of electron injection and transport relevant to the FI concept, which is crucial to understand electron transport in integral FI targets. In the last two years we have also been preparing diagnostics and starting to extend the work to electron transport into hot targets. A complementary effort, the Advanced Concept Exploration (ACE) program for Fast Ignition, was funded starting in 2006 to integrate this understanding into ignition schemes specifically suitable for the initial fast ignition attempts on OMEGA and National Ignition Facility (NIF), and during that time these two programs have been managed as a coordinated effort. This result of our 7+ years of effort has been substantial. Utilizing collaborations to access the most capable laser facilities around the world, we have developed an understanding that was summarized in a Fusion Science & Technology 2006, Special Issue on Fast Ignition. The author lists in the 20 articles in that issue are dominated by our group (we are first authors in four of them). Our group has published, or submitted 67 articles, including 1 in Nature, 2 Nature Physics, 10 Physical Review Letters, 8 Review of Scientific Instruments, and has been invited to give numerous talks at national and international conferences (including APS-DPP, IAEA, FIW). The advent of PW capabilities – at Rutherford Appleton Lab (UK) and then at Titan (LLNL) (2005 and 2006, respectively), was a major step toward experiments in ultra-high intensity high-energy FI relevant regime. The next step comes with the activation of OMEGA EP at LLE, followed shortly by NIF-ARC at LLNL. These capabilities allow production of hot dense material for electron transport studies. In this transitional period, considerable effort has been spent in developing the necessary tools and experiments for electron transport in hot and dense plasmas. In addition, substantial new data on electron generation and transport in metallic targets has been produced and analyzed. Progress in FI detailed in §2 is related to the Concept Exploration Program (CEP) objectives; this section is a summary of the publications and presentations listed in §5. This work has benefited from the synergy with work on related Department of Energy (DOE) grants, the Fusion Science Center and the Fast Ignition Advanced Concept Exploration grant, and from our interactions with overseas colleagues, primarily at Rutherford Appleton Laboratory in the UK, and the Institute for Laser Engineering in Japan.

Stephens, Richarad Burnite [General Atomics] [General Atomics; Freeman, Richard R. [The Ohio State University] [The Ohio State University; Van Woekom, L. D. [The Ohio State University] [The Ohio State University; Key, M. [Lawrence Livermore National Laboratory] [Lawrence Livermore National Laboratory; MacKinnon, Andrew J. [Lawrence Livermore National Laboratory] [Lawrence Livermore National Laboratory; Wei, Mingsheng [General Atomics] [General Atomics

2014-02-27T23:59:59.000Z

292

Advanced Gasoline Turbocharged Direct Injection (GTDI) Engine...  

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

combustion system includes "micro" stratified charge capability Air Flow & Air Fuel Spatial & Temporal Evolution "Micro" Stratified Charge * Overall Lean Homogeneous * Early...

293

Advanced Gasoline Turbocharged Direct Injection (GTDI) Engine...  

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

Company proposed a 4 year project addressing the solicitation from the Department of Energy Recovery Act - Systems Level Technology Development, Integration, and Demonstration...

294

Advanced Gasoline Turbocharged Direct Injection (GTDI) Engine...  

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

1 DOE Hydrogen and Fuel Cells Program, and Vehicle Technologies Program Annual Merit Review and Peer Evaluation ace065rinkevich2011...

295

Advanced Gasoline Turbocharged Direct Injection (GTDI) Engine...  

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

2 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting ace065weaver2012...

296

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

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

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

297

Review of the National Ignition Campaign 2009-2012  

SciTech Connect

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

298

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:...

299

Advanced CFD Models for High Efficiency Compression Ignition Engines  

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

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

300

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

Note: This page contains sample records for the topic "ignition direct injection" 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

Synthesizing aluminum particles towards controlling electrostatic discharge ignition sensitivity  

SciTech Connect

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

302

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

303

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

NLE Websites -- All DOE Office Websites (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...

304

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

305

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 &...

306

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

SciTech Connect

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

307

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

308

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

309

Jet plume injection and combustion system for internal combustion engines  

DOE Patents (OSTI)

An improved combustion system for an internal combustion engine is disclosed wherein a rich air/fuel mixture is furnished at high pressure to one or more jet plume generator cavities adjacent to a cylinder and then injected through one or more orifices from the cavities into the head space of the cylinder to form one or more turbulent jet plumes in the head space of the cylinder prior to ignition of the rich air/fuel mixture in the cavity of the jet plume generator. The portion of the rich air/fuel mixture remaining in the cavity of the generator is then ignited to provide a secondary jet, comprising incomplete combustion products which are injected into the cylinder to initiate combustion in the already formed turbulent jet plume. Formation of the turbulent jet plume in the head space of the cylinder prior to ignition has been found to yield a higher maximum combustion pressure in the cylinder, as well as shortening the time period to attain such a maximum pressure.

Oppenheim, Antoni K. (Kensington, CA); Maxson, James A. (Berkeley, CA); Hensinger, David M. (Albany, CA)

1993-01-01T23:59:59.000Z

310

Optimizing the design of a hydrogen engine with pilot diesel fuel ignition  

Science Journals Connector (OSTI)

A diesel engine was converted to dual-fuel hydrogen operation, ignition being started by a 'pilot' quantity of diesel fuel but with 65 to 90% of the energy being supplied as hydrogen. With later injection timing, use of delayed port admission of the gas, and a modified combustion chamber, thermal efficiencies were achieved nearly 15% greater than those for diesel as the sole fuel. A 'solid' water injection technique was used to curb knock under full load conditions when the power output equalled or exceeded that of a similar diesel engine. The indicator diagrams under these conditions closely approach those of the Otto cycle. The development was assisted by computer simulation using a novel self-ignition and flame propagation model. The very fast burning rates obtained with stoichiometric hydrogen-air mixtures show combustion to occur within 5 degrees of crank rotation yet Otto cycle thermal efficiency was not achieved. However, greenhouse gases are shown to be reduced by more than 80%, nitrogen oxides by up to 70%, and exhaust smoke by nearly 80%.

S.M. Lambe; H.C. Watson

1993-01-01T23:59:59.000Z

311

Fluidized bed injection assembly for coal gasification  

DOE Patents (OSTI)

A coaxial feed system for fluidized bed coal gasification processes including an inner tube for injecting particulate combustibles into a transport gas, an inner annulus about the inner tube for injecting an oxidizing gas, and an outer annulus about the inner annulus for transporting a fluidizing and cooling gas. The combustibles and oxidizing gas are discharged vertically upward directly into the combustion jet, and the fluidizing and cooling gas is discharged in a downward radial direction into the bed below the combustion jet.

Cherish, Peter (Bethel Park, PA); Salvador, Louis A. (Hempfield Township, Westmoreland County, PA)

1981-01-01T23:59:59.000Z

312

Low-Load Dual-Fuel Compression Ignition (CI) Engine Operation with an On-Board Reformer and a Diesel Oxidation Catalyst: Effects on Engine Performance and Emissions  

Science Journals Connector (OSTI)

Ideally, homogeneous air fuel mixtures ignited spontaneously exhibit less pollutants and can improve engine efficiency compared to standard diesel combustion, which is based on diffusion combustion. ... Although optimization of the injection timing of the in-cylinder DI fuel (e.g., diesel) aims to ignite the mixture and control the start of combustion (SOC) for the different premixed fuel ratios, the fuel ignition timing is complicated and problematic for a dual-fueled engine under a number of engine-operating conditions (e.g., low loads and use of residual gas trapping). ... Deactivation due to coking of a single Ni/Pt-based catalyst is significant, but operation using a platinum-ceria catalyst in line with a Ni-based steam-reforming catalyst allows acceptable efficiencies. ...

A. Tsolakis; R. Torbati; A. Megaritis; A. Abu-Jrai

2009-10-07T23:59:59.000Z

313

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

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

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

314

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

SciTech Connect

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

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

2011-10-27T23:59:59.000Z

315

Recent progress on the Compact Ignition Tokamak (CIT)  

SciTech Connect

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

316

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

317

Study Reveals Fuel Injection Timing Impact on Particle Number...  

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

increasingly turning to gasoline direct injection (GDI) coupled with turbocharging as a cost-effective option for improving the efficiency and performance of gasoline engines....

318

Current Injection Spiral-Shaped Chaotic Microcavity Quantum Cascade Lasers  

Science Journals Connector (OSTI)

We report room temperature operation of current-injection quantum cascade lasers with spiral-shaped chaotic microresonators, capable of directional, single mode emission, operating...

Belkin, Mikhail A; Audet, Ross M; Fan, Jonathan A; Capasso, Federico; Narimanov, Evgenii; Bour, D; Corzine, S; Zhu, J; Höfler, G

319

Status of the National Ignition Facility project  

SciTech Connect

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

320

National Ignition Facility project acquisition plan  

SciTech Connect

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

Callaghan, R.W.

1996-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "ignition direct injection" 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

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

SciTech Connect

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

322

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

323

Effect of the use of olive–pomace oil biodiesel/diesel fuel blends in a compression ignition engine: Preliminary exergy analysis  

Science Journals Connector (OSTI)

Abstract Although biodiesel is among the most studied biofuels for diesel engines, it is usually produced from edible oils, which gives way to controversy between the use of land for fuel and food. For this reason, residues like olive–pomace oil are considered alternative raw materials to produce biodiesel that do not compete with the food industry. To gain knowledge about the implications of its use, olive–pomace oil methyl ester, straight and blended with diesel fuel, was evaluated as fuel in a direct injection diesel engine Perkins AD 3-152 and compared to the use of fossil diesel fuel. Performance curves were analyzed at full load and different speed settings. To perform the exergy balance of the tested fuels, the operating conditions corresponding to maximum engine power values were considered. It was found that the tested fuels offer similar performance parameters. When straight biodiesel was used instead of diesel fuel, maximum engine power decreased to 5.6%, while fuel consumption increased up to 7%. However, taking into consideration the Second Law of the Thermodynamics, the exergy efficiency and unitary exergetic cost reached during the operation of the engine under maximum power condition for the assessed fuels do not display significant differences. Based on the exergy results, it may be concluded that olive–pomace oil biodiesel and its blends with diesel fuel may substitute the use of diesel fuel in compression ignition engines without any exergy cost increment.

I. López; C.E. Quintana; J.J. Ruiz; F. Cruz-Peragón; M.P. Dorado

2014-01-01T23:59:59.000Z

324

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

325

Catalytic ignition of fuel/oxygen/nitrogen mixtures over platinum  

SciTech Connect

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

326

Pre-ignition laser ablation of nanocomposite energetic materials  

SciTech Connect

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

327

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

328

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

329

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

330

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

SciTech Connect

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

331

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

332

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

333

Flame structure of wall-impinging diesel fuel sprays injected by group-hole nozzles  

SciTech Connect

This paper describes an investigation of the flame structure of wall-impinging diesel sprays injected by group-hole nozzles in a constant-volume combustion vessel at experimental conditions typical of a diesel engine. The particular emphasis was on the effect of the included angle between two orifices (0-15 deg. in current study) on the flame structure and combustion characteristics under various simulated engine load conditions. The laser absorption scattering (LAS) technique was applied to analyze the spray and mixture properties. Direct flame imaging and OH chemiluminescence imaging were utilized to quantify the ignition delay, flame geometrical parameters, and OH chemiluminescence intensity. The images show that the asymmetric flame structure emerges in wall-impinging group-hole nozzle sprays as larger included angle and higher engine load conditions are applied, which is consistent with the spray shape observed by LAS. Compared to the base nozzle, group-hole nozzles with large included angles yield higher overall OH chemiluminescence intensity, wider flame area, and greater proportion of high OH intensity, implying the better fuel/air mixing and improved combustion characteristics. The advantages of group-hole nozzle are more pronounced under high load conditions. Based on the results, the feasibility of group-hole nozzle for practical direct injection diesel engines is also discussed. It is concluded that the asymmetric flame structure of a group-hole nozzle spray is favorable to reduce soot formation over wide engine loads. However, the hole configuration of the group-hole nozzle should be carefully considered so as to achieve proper air utilization in the combustion chamber. Stoichiometric diesel combustion is another promising application of group-hole nozzle. (author)

Gao, Jian; Moon, Seoksu; Nishida, Keiya; Matsumoto, Yuhei [Department of Mechanical System Engineering, University of Hiroshima, Higashi-Hiroshima, 739-8527 (Japan); Zhang, Yuyin [Department of Mechanical Engineering, Tokyo Denki University, Tokyo, 101-8457 (Japan)

2009-06-15T23:59:59.000Z

334

Instrumentation and controls of an ignited tokamak  

SciTech Connect

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

335

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

336

Direct-Drive Inertial Confinement Fusion Research at the Laboratory for Laser Energetics  

E-Print Network (OSTI)

-ray spectroscopy Main laser drive Rayleigh­Taylor and Bell­Plesset growth DT gas Fusion burn/ignition HotDirect-Drive Inertial Confinement Fusion Research at the Laboratory for Laser Energetics: Charting the Path to Thermonuclear Ignition 20th IAEA Fusion Energy Conference Vilamoura, Portugal 1­6 November 2004

337

Director of the National Ignition Facility, Lawrence Livermore National  

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

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

338

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

339

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

340

National Ignition Facility & Photon Science HOW NIF WORKS  

NLE Websites -- All DOE Office Websites (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...

Note: This page contains sample records for the topic "ignition direct injection" 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

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

342

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

343

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

344

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

345

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

346

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

347

High Fidelity Modeling of Premixed Charge Compression Ignition Engines  

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

348

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

349

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

350

Orthogonal ion injection apparatus and process  

DOE Patents (OSTI)

An orthogonal ion injection apparatus and process are described in which ions are directly injected into an ion guide orthogonal to the ion guide axis through an inlet opening located on a side of the ion guide. The end of the heated capillary is placed inside the ion guide such that the ions are directly injected into DC and RF fields inside the ion guide, which efficiently confines ions inside the ion guide. Liquid droplets created by the ionization source that are carried through the capillary into the ion guide are removed from the ion guide by a strong directional gas flow through an inlet opening on the opposite side of the ion guide. Strong DC and RF fields divert ions into the ion guide. In-guide orthogonal injection yields a noise level that is a factor of 1.5 to 2 lower than conventional inline injection known in the art. Signal intensities for low m/z ions are greater compared to convention inline injection under the same processing conditions.

Kurulugama, Ruwan T; Belov, Mikhail E

2014-04-15T23:59:59.000Z

351

Activated Carbon Injection  

ScienceCinema (OSTI)

History of the Clean Air Act and how the injection of carbon into a coal power plant's flu smoke can reduce the amount of mercury in the smoke.

None

2014-07-22T23:59:59.000Z

352

Underground Injection Control (Louisiana)  

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

The Injection and Mining Division (IMD) has the responsibility of implementing two major federal environmental programs which were statutorily charged to the Office of Conservation: the Underground...

353

NEUTRAL-BEAM INJECTION  

E-Print Network (OSTI)

energy, coming from an electron source, are injected intodischarges. In an electron bombardment source electrons ofsimply called electron bombardment sources (Kaufman, 1974).

Kunkel, W.B.

2012-01-01T23:59:59.000Z

354

Activated Carbon Injection  

SciTech Connect

History of the Clean Air Act and how the injection of carbon into a coal power plant's flu smoke can reduce the amount of mercury in the smoke.

None

2014-07-16T23:59:59.000Z

355

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

SciTech Connect

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

356

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

357

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

Science Journals Connector (OSTI)

Energy spectra and spectrally resolved one-dimensional fluence images of self-emitted charged-fusion products (14.7 MeV D3He protons) are routinely measured from indirectly driven inertial-confinement fusion (ICF) experiments utilizing ignition-scaled hohlraums at the National Ignition Facility (NIF). A striking and consistent feature of these images is that the fluence of protons leaving the ICF target in the direction of the hohlraum's laser entrance holes (LEHs) is very nonuniform spatially, in contrast to the very uniform fluence of protons leaving through the hohlraum equator. In addition, the measured nonuniformities are unpredictable, and vary greatly from shot to shot. These observations were made separately at the times of shock flash and of compression burn, indicating that the asymmetry persists even at ~0.5–2.5 ns after the laser has turned off. These phenomena have also been observed in experiments on the OMEGA laser facility with energy-scaled hohlraums, suggesting that the underlying physics is similar. Comprehensive data sets provide compelling evidence that the nonuniformities result from proton deflections due to strong spontaneous electromagnetic fields around the hohlraum LEHs. Although it has not yet been possible to uniquely determine whether the fields are magnetic (B) or electric (E), preliminary analysis indicates that the strength is ~1 MG if B fields or ~109 V cm?1 if E fields. These measurements provide important physics insight into the ongoing ignition experiments at the NIF. Understanding the generation, evolution, interaction and dissipation of the self-generated fields may help to answer many physics questions, such as why the electron temperatures measured in the LEH region are anomalously large, and may help to validate hydrodynamic models of plasma dynamics prior to plasma stagnation in the center of the hohlraum.

C K Li; A B Zylstra; J A Frenje; F H Séguin; N Sinenian; R D Petrasso; P A Amendt; R Bionta; S Friedrich; G W Collins; E Dewald; T Döppner; S H Glenzer; D G Hicks; O L Landen; J D Kilkenny; A J Mackinnon; N Meezan; J Ralph; J R Rygg; J Kline; G Kyrala

2013-01-01T23:59:59.000Z

358

Target Diagnostics Supports NIF's Path to Ignition  

SciTech Connect

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

Shelton, R

2011-12-07T23:59:59.000Z

359

Predicting Ignition Delay for Gas Turbine Fuel Flexibility  

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

Ignition Delay for Ignition Delay for Gas Turbine Fuel Flexibility 15 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

360

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

Note: This page contains sample records for the topic "ignition direct injection" 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

Advanced Combustion Operation in a Compression Ignition Engine  

Science Journals Connector (OSTI)

In this study, advanced combustion operating modes were investigated on a DDC/VM Motori 2.5 L, four-cylinder, turbocharged, common rail, direct-injection light-duty diesel engine, with exhaust emission being the main focus. ... This process is based on work from Al-Qurashi et al., who conducted fundamental flame studies that showed that the thermal effect of EGR enhances the oxidative reactivity of diesel soot. ... Heywood, J. B. Internal Combustion Engine Fundamentals; McGraw-Hill Book Company: New York, 1988; p 930. ...

Gregory K. Lilik; José Martín Herreros; André L. Boehman

2008-12-15T23:59:59.000Z

362

Fast-ignition transport studies: Realistic electron source, integrated particle-in-cell and hydrodynamic modeling, imposed magnetic fields  

SciTech Connect

Transport modeling of idealized, cone-guided fast ignition targets indicates the severe challenge posed by fast-electron source divergence. The hybrid particle-in-cell (PIC) code Zuma is run in tandem with the radiation-hydrodynamics code Hydra to model fast-electron propagation, fuel heating, and thermonuclear burn. The fast electron source is based on a 3D explicit-PIC laser-plasma simulation with the PSC code. This shows a quasi two-temperature energy spectrum and a divergent angle spectrum (average velocity-space polar angle of 52 Degree-Sign ). Transport simulations with the PIC-based divergence do not ignite for >1 MJ of fast-electron energy, for a modest (70 {mu}m) standoff distance from fast-electron injection to the dense fuel. However, artificially collimating the source gives an ignition energy of 132 kJ. To mitigate the divergence, we consider imposed axial magnetic fields. Uniform fields {approx}50 MG are sufficient to recover the artificially collimated ignition energy. Experiments at the Omega laser facility have generated fields of this magnitude by imploding a capsule in seed fields of 50-100 kG. Such imploded fields will likely be more compressed in the transport region than in the laser absorption region. When fast electrons encounter increasing field strength, magnetic mirroring can reflect a substantial fraction of them and reduce coupling to the fuel. A hollow magnetic pipe, which peaks at a finite radius, is presented as one field configuration which circumvents mirroring.

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

2012-07-15T23:59:59.000Z

363

National Ignition Facility Project Site Safety Program  

SciTech Connect

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

364

The National Ignition Facility and the Path to Fusion Energy  

SciTech Connect

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

Moses, E

2011-07-26T23:59:59.000Z

365

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

SciTech Connect

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

366

Compression ignition engine performance and emission evaluation of industrial oilseed biofuel feedstocks camelina, carinata, and pennycress across three fuel pathways  

Science Journals Connector (OSTI)

Abstract Industrial oilseeds camelina (Camelina sativa L.), carinata (Brassica carinata), and pennycress (Thlaspi arvense L.) offer great potential as biofuel feedstocks due to their non-food nature and positive agronomic attributes. This research focused on compression ignition (CI) engine performance and emissions of these industrial oilseeds as compared to both traditional feedstocks and petroleum diesel. A John Deere 4.5 L test engine was used to evaluate these oils using three fuel pathways (triglyceride blends, biodiesel, and renewable diesel). This engine research represents the first direct comparison of these new biofuel feedstocks to each other and to conventional sources. For some industrial oilseed feedstock and fuel pathway combinations, this study also represents the first engine performance data available. The results were promising, with camelina, carinata, and pennycress engine performance very similar to the traditional oils for each fuel pathway. Fuel consumption, thermal efficiency, and emissions were all were typical as compared to traditional oilseed feedstocks. Average brake specific fuel consumption (bsfc) for the industrial oilseed biofuels was within ±1.3% of the conventional oilseed biofuels for each fuel type. Initial research with triglyceride blends (TGB), formed by blending straight vegetable oil with gasoline, indicate it may be an ideal fuel pathway for farm-scale fuel production, and was compatible with a direct injection CI engine without modification. TGB had lower fuel consumption and a higher thermal efficiency than biodiesel for each feedstock tested. For several categories, TGB performed similar to petroleum diesel. TGB volumetric bsfc was only 1.9% higher than the petroleum runs. TGB combustion characteristics were similar to biodiesel. Biodiesel runs had several emission benefits such as reductions in carbon monoxide (CO), non-methane hydrocarbons (NMHC), volatile organic compounds (VOCs), and formaldehyde (CH20) emissions as compared to TGB runs. The renewable diesels had petroleum-like engine performance and combustion characteristics, while still maintaining some of the benefits of biodiesel such as reduced CO emissions. Nitrogen oxides (NOx) emissions were also 6% lower for renewable diesel runs than petroleum. Both crude and refined oil was used as feedstock, and did not significantly affect engine performance or emissions in a modern CI engine.

A.C. Drenth; D.B. Olsen; P.E. Cabot; J.J. Johnson

2014-01-01T23:59:59.000Z

367

Evaluating the ignition sensitivity of thermal battery heat pellets  

SciTech Connect

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

368

Symmetry tuning for ignition capsules via the symcap technique  

SciTech Connect

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

369

Injection-Induced Earthquakes  

Science Journals Connector (OSTI)

...injected into the reservoir under high pressure...core samples of the reservoir rocks and in situ determination...fracture-dominated porosity of less than 6...Implications for reservoir fracture permeability . AAPG Bull. 93...

William L. Ellsworth

2013-07-12T23:59:59.000Z

370

Injection Laser System  

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

Injection Laser System For each of NIF's 192 beams: The pulse shape as a function of time must be generated with a high degree of precision The energy delivered to the target must...

371

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

372

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

373

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

374

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

375

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

376

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

377

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

378

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

SciTech Connect

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

379

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

380

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

Note: This page contains sample records for the topic "ignition direct injection" 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

Shock timing on the National Ignition Facility: First Experiments  

SciTech Connect

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

382

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

383

A TUTORIAL ON IGNITION AND GAIN FOR SMALL FUSION TARGETS  

SciTech Connect

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

384

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.

385

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

386

Features of a point design for fast ignition  

SciTech Connect

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

387

Progress toward Ignition with Noncryogenic Double-Shell Capsules  

SciTech Connect

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

388

High Performance Imaging Streak Camera for the National Ignition Facility  

SciTech Connect

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

389

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

390

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

391

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

392

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

393

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

394

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

395

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

396

Hole boring in a DT pellet and fast ion ignition with ultra-intense laser pulses  

E-Print Network (OSTI)

Recently achieved high intensities of short laser pulses open new prospects in their application to hole boring in inhomogeneous overdense plasmas and for ignition in precompressed DT fusion targets. A simple analytical model and numerical simulations demonstrate that pulses with intensities exceeding 1022 W/cm2 may penetrate deeply into the plasma as a result of efficient ponderomotive acceleration of ions in the forward direction. The penetration depth as big as hundreds of microns depends on the laser fluence, which has to exceed a few tens of GJ/cm2. The fast ions, accelerated at the bottom of the channel with an efficiency of more than 20%, show a high directionality and may heat the precompressed target core to fusion conditions.

Naumova, N; Tikhonchuk, V T; Labaune, C; Sokolov, I V; Mourou, G; 10.1103/PhysRevLett.102.025002

2009-01-01T23:59:59.000Z

397

Optimization of Injection Scheduling in  

E-Print Network (OSTI)

SGP-TR-I12 Optimization of Injection Scheduling in Geothermal Fields James Lovekin May 1987&injection optimization problem is broke$ into two subpmbkm:(1) choosing a configuration of injectorsfrom an existing set is defined as the fieldwide break- through lindex, B. Injection is optimized by choosing injection wells

Stanford University

398

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

399

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

400

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

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

Note: This page contains sample records for the topic "ignition direct injection" 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

Nitrogen Control in Electric Arc Furnace Steelmaking by Direct...  

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

Nitrogen Control in Electric Arc Furnace Steelmaking by Direct Reduced Iron Fines Injection Nitrogen Control in Electric Arc Furnace Steelmaking by Direct Reduced Iron Fines...

402

Experimental and Kinetic Modeling Study of Extinction and Ignition of Methyl Decanoate in Laminar Nonpremixed Flows  

SciTech Connect

Methyl decanoate is a large methyl ester that can be used as a surrogate for biodiesel. In this experimental and computational study, the combustion of methyl decanoate is investigated in nonpremixed, nonuniform flows. Experiments are performed employing the counterflow configuration with a fuel stream made up of vaporized methyl decanoate and nitrogen, and an oxidizer stream of air. The mass fraction of fuel in the fuel stream is measured as a function of the strain rate at extinction, and critical conditions of ignition are measured in terms of the temperature of the oxidizer stream as a function of the strain rate. It is not possible to use a fully detailed mechanism for methyl decanoate to simulate the counterflow flames because the number of species and reactions is too large to employ with current flame codes and computer resources. Therefore a skeletal mechanism was deduced from a detailed mechanism of 8555 elementary reactions and 3036 species using 'directed relation graph' method. This skeletal mechanism has only 713 elementary reactions and 125 species. Critical conditions of ignition were calculated using this skeletal mechanism and are found to agree well with experimental data. The predicted strain rate at extinction is found to be lower than the measurements. In general, the methyl decanoate mechanism provides a realistic kinetic tool for simulation of biodiesel fuels.

Seshadri, K; Lu, T; Herbinet, O; Humer, S; Niemann, U; Pitz, W J; Law, C K

2008-01-09T23:59:59.000Z

403

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

404

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.

405

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

406

Semiconductor bridge: A plasma generator for the ignition of explosives  

SciTech Connect

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

407

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

408

Ignition of HMX (cyclotetramethylenetetranitramine) using low energy laser diodes  

SciTech Connect

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

409

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

410

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

411

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

SciTech Connect

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

412

Railplug Ignition System for Enhanced Engine Performance and Reduced Maintenance  

SciTech Connect

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

DK Ezekoye; Matt Hall; Ron Matthews

2005-08-01T23:59:59.000Z

413

Development of the CD Symcap platform to study gas-shell mix in implosions at the National Ignition Facility  

SciTech Connect

Surrogate implosions play an important role at the National Ignition Facility (NIF) for isolating aspects of the complex physical processes associated with fully integrated ignition experiments. The newly developed CD Symcap platform has been designed to study gas-shell mix in indirectly driven, pure T{sub 2}-gas filled CH-shell implosions equipped with 4 ?m thick CD layers. This configuration provides a direct nuclear signature of mix as the DT yield (above a characterized D contamination background) is produced by D from the CD layer in the shell, mixing into the T-gas core. The CD layer can be placed at different locations within the CH shell to probe the depth and extent of mix. CD layers placed flush with the gas-shell interface and recessed up to 8??m have shown that most of the mix occurs at the inner-shell surface. In addition, time-gated x-ray images of the hotspot show large brightly radiating objects traversing through the hotspot around bang-time, which are likely chunks of CH/CD plastic. This platform is a powerful new capability at the NIF for understanding mix, one of the key performance issues for ignition experiments.

Casey, D. T.; Smalyuk, V. A.; Tipton, R. E.; Pino, J. E.; Remington, B. A.; Rowley, D. P.; Weber, S. V.; Barrios, M.; Benedetti, L. R.; Bleuel, D. L.; Bond, E. J.; Bradley, D. K.; Caggiano, J. A.; Callahan, D. A.; Cerjan, C. J.; Edwards, M. J.; Fittinghoff, D.; Glenn, S.; Haan, S. W.; Hamza, A. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); and others

2014-09-15T23:59:59.000Z

414

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

SciTech Connect

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

415

Replenishing data descriptors in a DMA injection FIFO buffer  

DOE Patents (OSTI)

Methods, apparatus, and products are disclosed for replenishing data descriptors in a Direct Memory Access (`DMA`) injection first-in-first-out (`FIFO`) buffer that include: determining, by a messaging module on an origin compute node, whether a number of data descriptors in a DMA injection FIFO buffer exceeds a predetermined threshold, each data descriptor specifying an application message for transmission to a target compute node; queuing, by the messaging module, a plurality of new data descriptors in a pending descriptor queue if the number of the data descriptors in the DMA injection FIFO buffer exceeds the predetermined threshold; establishing, by the messaging module, interrupt criteria that specify when to replenish the injection FIFO buffer with the plurality of new data descriptors in the pending descriptor queue; and injecting, by the messaging module, the plurality of new data descriptors into the injection FIFO buffer in dependence upon the interrupt criteria.

Archer, Charles J. (Rochester, MN); Blocksome, Michael A. (Rochester, MN); Cernohous, Bob R. (Rochester, MN); Heidelberger, Philip (Cortlandt Manor, NY); Kumar, Sameer (White Plains, NY); Parker, Jeffrey J. (Rochester, MN)

2011-10-11T23:59:59.000Z

416

Pressurized feed-injection spray-forming apparatus  

DOE Patents (OSTI)

A spray apparatus and method for injecting a heated, pressurized liquid in a first predetermined direction into a pressurized gas flow that is flowing in a second predetermined direction, to provide for atomizing and admixing the liquid with the gas to form a two-phase mixture. A valve is also disposed within the injected liquid conduit to provide for a pulsed injection of the liquid and timed deposit of the atomized gas phase. Preferred embodiments include multiple liquid feed ports and reservoirs to provide for multiphase mixtures of metals, ceramics, and polymers.

Berry, Ray A. (Idaho Falls, ID); Fincke, James R. (Idaho Falls, ID); McHugh, Kevin M. (Idaho Falls, ID)

1995-01-01T23:59:59.000Z

417

Pressurized feed-injection spray-forming apparatus  

DOE Patents (OSTI)

A spray apparatus and method are disclosed for injecting a heated, pressurized liquid in a first predetermined direction into a pressurized gas flow that is flowing in a second predetermined direction, to provide for atomizing and admixing the liquid with the gas to form a two-phase mixture. A valve is also disposed within the injected liquid conduit to provide for a pulsed injection of the liquid and timed deposit of the atomized gas phase. Preferred embodiments include multiple liquid feed ports and reservoirs to provide for multiphase mixtures of metals, ceramics, and polymers. 22 figs.

Berry, R.A.; Fincke, J.R.; McHugh, K.M.

1995-08-29T23:59:59.000Z

418

Injection-controlled laser resonator  

DOE Patents (OSTI)

A new injection-controlled laser resonator incorporates self-filtering and self-imaging characteristics with an efficient injection scheme. A low-divergence laser signal is injected into the resonator, which enables the injection signal to be converted to the desired resonator modes before the main laser pulse starts. This injection technique and resonator design enable the laser cavity to improve the quality of the injection signal through self-filtering before the main laser pulse starts. The self-imaging property of the present resonator reduces the cavity induced diffraction effects and, in turn, improves the laser beam quality. 5 figs.

Chang, J.J.

1995-07-18T23:59:59.000Z

419

Methanol vaporization and injection system for internal combustion engine  

SciTech Connect

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

420

Effect of different percentages of biodiesel–diesel blends on injection, spray, combustion, performance, and emission characteristics of a diesel engine  

Science Journals Connector (OSTI)

Abstract A comparative study of effect of different biodiesel–diesel blends (B5, B10, B15, B20, B25, B50 and B100) on injection, spray, combustion, performance, and emissions of a direct injection diesel engine at constant speed (1500 rpm) was carried out. The penetration distance increased with increase in percentage of biodiesel in diesel due to enhanced in-line fuel pressure. The simulation results indicate the spray penetration with biodiesel–diesel blend up to B15 does not lead to wall impingement but B20 is to be a critical limit of wall impingement (within uncertainty ±1.3%). However, it is observed clearly from the simulation results that probability of wall impingement is more with higher blends (B25, B50 and B100). The ignition delay period decreased with all biodiesel blends due to higher cetane number resulting in less rate of pressure rise and the smooth engine running operation. The engine torque does not change significantly with biodiesel–diesel blends up to 20% (B20). However, the torque reduction is about 2.7% with B100 at the rated load. Carbon monoxide (CO), hydrocarbon (HC) and smoke emissions decreased with all biodiesel–diesel blends. However, oxides of nitrogen (NOx) emission increased in the range of 1.4–22.8% with all biodiesel–diesel blends at rated load due to oxygenated fuel, automatic advance in dynamic injection timing (DIT), higher penetration and higher in-cylinder temperature. A notable conclusion emerged from this study is the optimum biodiesel–diesel blend based on no wall impingement (B15: 0% and B20 ±1.3% uncertainty limit) and increase in \\{NOx\\} emission (B15: 4.1% and B20: 15.6%) in a conventional (unmodified) diesel engine is up to B15.

Subhash Lahane; K.A. Subramanian

2015-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ignition direct injection" 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

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

422

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

SciTech Connect

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

423

An Investigation Into Bayesian Networks for Modeling National Ignition Facility Capsule Implosions  

SciTech Connect

Bayesian networks (BN) are an excellent tool for modeling uncertainties in systems with several interdependent variables. A BN is a directed acyclic graph, and consists of a structure, or the set of directional links between variables that depend on other variables, and conditional probabilities (CP) for each variable. In this project, we apply BN's to understand uncertainties in NIF ignition experiments. One can represent various physical properties of National Ignition Facility (NIF) capsule implosions as variables in a BN. A dataset containing simulations of NIF capsule implosions was provided. The dataset was generated from a radiation hydrodynamics code, and it contained 120 simulations of 16 variables. Relevant knowledge about the physics of NIF capsule implosions and greedy search algorithms were used to search for hypothetical structures for a BN. Our preliminary results found 6 links between variables in the dataset. However, we thought there should have been more links between the dataset variables based on the physics of NIF capsule implosions. Important reasons for the paucity of links are the relatively small size of the dataset, and the sampling of the values for dataset variables. Another factor that might have caused the paucity of links is the fact that in the dataset, 20% of the simulations represented successful fusion, and 80% didn't, (simulations of unsuccessful fusion are useful for measuring certain diagnostics) which skewed the distributions of several variables, and possibly reduced the number of links. Nevertheless, by illustrating the interdependencies and conditional probabilities of several parameters and diagnostics, an accurate and complete BN built from an appropriate simulation set would provide uncertainty quantification for NIF capsule implosions.

Mitrani, J

2008-08-18T23:59:59.000Z

424

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

425

Laser design basis for the National Ignition Facility  

SciTech Connect

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

426

Hydrodynamic instabilities in beryllium targets for the National Ignition Facility  

SciTech Connect

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

427

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

428

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

429

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

430

Liquid Propane Injection Applications  

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

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

431

Fluid-Bed Testing of Greatpoint Energy's Direct Oxygen Injection Catalytic Gasification Process for Synthetic Natural Gas and Hydrogen Coproduction Year 6 - Activity 1.14 - Development of a National Center for Hydrogen Technology  

SciTech Connect

The GreatPoint Energy (GPE) concept for producing synthetic natural gas and hydrogen from coal involves the catalytic gasification of coal and carbon. GPE’s technology “refines” coal by employing a novel catalyst to “crack” the carbon bonds and transform the coal into cleanburning methane (natural gas) and hydrogen. The GPE mild “catalytic” gasifier design and operating conditions result in reactor components that are less expensive and produce pipeline-grade methane and relatively high purity hydrogen. The system operates extremely efficiently on very low cost carbon sources such as lignites, subbituminous coals, tar sands, petcoke, and petroleum residual oil. In addition, GPE’s catalytic coal gasification process eliminates troublesome ash removal and slagging problems, reduces maintenance requirements, and increases thermal efficiency, significantly reducing the size of the air separation plant (a system that alone accounts for 20% of the capital cost of most gasification systems) in the catalytic gasification process. Energy & Environmental Research Center (EERC) pilot-scale gasification facilities were used to demonstrate how coal and catalyst are fed into a fluid-bed reactor with pressurized steam and a small amount of oxygen to “fluidize” the mixture and ensure constant contact between the catalyst and the carbon particles. In this environment, the catalyst facilitates multiple chemical reactions between the carbon and the steam on the surface of the coal. These reactions generate a mixture of predominantly methane, hydrogen, and carbon dioxide. Product gases from the process are sent to a gas-cleaning system where CO{sub 2} and other contaminants are removed. In a full-scale system, catalyst would be recovered from the bottom of the gasifier and recycled back into the fluid-bed reactor. The by-products (such as sulfur, nitrogen, and CO{sub 2}) would be captured and could be sold to the chemicals and petroleum industries, resulting in near-zero hazardous air or water pollution. This technology would also be conducive to the efficient coproduction of methane and hydrogen while also generating a relatively pure CO{sub 2} stream suitable for enhanced oil recovery (EOR) or sequestration. Specific results of bench-scale testing in the 4- to 38-lb/hr range in the EERC pilot system demonstrated high methane yields approaching 15 mol%, with high hydrogen yields approaching 50%. This was compared to an existing catalytic gasification model developed by GPE for its process. Long-term operation was demonstrated on both Powder River Basin subbituminous coal and on petcoke feedstocks utilizing oxygen injection without creating significant bed agglomeration. Carbon conversion was greater than 80% while operating at temperatures less than 1400°F, even with the shorter-than-desired reactor height. Initial designs for the GPE gasification concept called for a height that could not be accommodated by the EERC pilot facility. More gas-phase residence time should allow the syngas to be converted even more to methane. Another goal of producing significant quantities of highly concentrated catalyzed char for catalyst recovery and material handling studies was also successful. A Pd–Cu membrane was also successfully tested and demonstrated to produce 2.54 lb/day of hydrogen permeate, exceeding the desired hydrogen permeate production rate of 2.0 lb/day while being tested on actual coal-derived syngas that had been cleaned with advanced warm-gas cleanup systems. The membranes did not appear to suffer any performance degradation after exposure to the cleaned, warm syngas over a nominal 100-hour test.

Swanson, Michael; Henderson, Ann

2012-04-01T23:59:59.000Z

432

HIGH-MODE RAYLEIGH-TAYLOR GROWTH IN NIF IGNITION CAPSULES  

SciTech Connect

An assessment of short wavelength hydrodynamic stability is an essential component in the optimization of NIF ignition target designs. Using highly-resolved massively-parallel 2-D Hydra simulations, we routinely evaluate target designs up to mode numbers of 2000 ({lambda} {approx} 2 {micro}m). On the outer ablator surface, mode numbers up to {approx}300 ({lambda} {approx} 20 {micro}m) can have significant growth in CH capsule designs. At the internal fuel:ablator interface mode numbers up to {approx}2000 are important for both CH and Be designs. In addition, 'isolated features' on the capsule, such as the 'fill-tube' ({approx} 5 {micro}m scale-length) and defects, can seed short wavelength growth at the ablation front and the fuel:ablator interface, leading to the injection of {approx} 10's ng of ablator material into the central hot-spot. We are developing methods to measure high-mode mix on NIF implosion experiments. X-ray spectroscopic methods are appealing since mix into the hot-spot will result in x-ray emission from the high-Z dopant (Cu or Ge) in the ablator material (Be or CH).

Hammel, B A; Haan, S W; Clark, D; Edwards, M J; Langer, S H; Marinak, M; Patel, M; Salmonson, J; Scott, H A

2009-08-04T23:59:59.000Z

433

Effectiveness of Diesel Oxidation Catalyst in Reducing HC and CO Emissions from Reactivity Controlled Compression Ignition  

SciTech Connect

Reactivity Controlled Compression Ignition (RCCI) has been shown to allow for diesel-like or better brake thermal efficiency with significant reductions in nitrogen oxide (NOX) particulate matter (PM) emissions. Hydrocarbon (HC) and carbon monoxide (CO) emission levels, on the other hand, are similar to those of port fuel injected gasoline engines. The higher HC and CO emissions combined with the lower exhaust temperatures with RCCI operation present a challenge for current exhaust aftertreatments. The reduction of HC and CO emissions in a lean environment is typically achieved with an oxidation catalyst. In this work, several diesel oxidation catalysts (DOC) with different precious metal loadings were evaluated for effectiveness to control HC and CO emissions from RCCI combustion in a light-duty multi-cylinder engine operating on gasoline and diesel fuels. Each catalyst was evaluated in a steady-state engine operation with temperatures ranging from 160 to 260 C. A shift to a higher light-off temperature was observed during the RCCI operation. In addition to the steady-state experiments, the performances of the DOCs were evaluated during multi-mode engine operation by switching from diesel-like combustion at higher exhaust temperature and low HC/CO emissions to RCCI combustion at lower temperature and higher HC/CO emissions. High CO and HC emissions from RCCI generated an exotherm keeping the catalyst above the light-off temperature.

Prikhodko, Vitaly Y [ORNL; Curran, Scott [ORNL; Parks, II, James E [ORNL; Wagner, Robert M [ORNL

2013-01-01T23:59:59.000Z

434

National Ignition Facility Cryogenic Target Systems Interim Management Plan  

SciTech Connect

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

435

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

436

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

437

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

438

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

439

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

440

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

Note: This page contains sample records for the topic "ignition direct injection" 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

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...

442

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

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

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

443

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

SciTech Connect

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

444

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

445

Experimental Target Injection and Tracking System  

SciTech Connect

Targets must be injected into an IFE power plant with an accuracy of and plusmn; 5 mm at a rate of approximately 5 to 10 each second. Targets must be tracked very accurately to allow driver beams to be aligned with defined points on the targets with accuracy {+-}200{mu}m for indirect drive and {+-}20{mu}m for direct drive. An experimental target injection and tracking system has been designed and is being constructed at General Atomics to investigate injection and tracking of both direct drive and indirect drive targets. The design is modular to allow testing of alternate target acceleration and tracking methods. The injector system will be used as a tool for testing the survivability of various target designs and provide feed back to the target designers. This 30 m long system will be the centerpiece of a Facility for developing IFE target fabrication and injection technologies. A high-speed high-flow gas valve (designed and built by Oak Ridge National Laboratory) will provide helium propellant gas to the targets. To avoid target damage from excessive acceleration, an 8 m gun barrel is being built to achieve 400 m/s target speed while not exceeding 10,000 m/s{sup 2} acceleration. Direct-drive targets are protected in the barrel by sabots that are spring loaded to separate into two halves after acceleration. A sabot deflector directs the sabot halves away from the target injection path. Gas expansion chambers and orifices, keep propellant gas out of the target-tracking region. Targets will be optically tracked with laser beams and line scan cameras. High-speed computations will calculate target position in less than 2 ms based on the output from the line-scan cameras. Target position and arrival time to a plane in the reaction chamber center will be predicted in real-time based on early target position measurements. The system design, construction progress, and early testing results will be presented.

Petzoldt, R.W. [General Atomics (United States); Alexander, N.B. [General Atomics (United States); Drake, T.J. [General Atomics (United States); Goodin, D.T. [General Atomics (United States); Stemke, R.W. [General Atomics (United States); Jonestrask, K

2003-07-15T23:59:59.000Z

446

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

SciTech Connect

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

447

Underground Injection Control Rule (Vermont)  

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

This rule regulates injection wells, including wells used by generators of hazardous or radioactive wastes, disposal wells within an underground source of drinking water, recovery of geothermal...

448

Underground Injection Control Regulations (Kansas)  

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

This article prohibits injection of hazardous or radioactive wastes into or above an underground source of drinking water, establishes permit conditions and states regulations for design,...

449

Injectivity Test | Open Energy Information  

Open Energy Info (EERE)

Injectivity Test Injectivity Test Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Injectivity Test Details Activities (7) Areas (6) Regions (0) NEPA(1) Exploration Technique Information Exploration Group: Downhole Techniques Exploration Sub Group: Well Testing Techniques Parent Exploration Technique: Well Testing Techniques Information Provided by Technique Lithology: Stratigraphic/Structural: Hydrological: Permeability of the well Thermal: Dictionary.png Injectivity Test: A well testing technique conducted upon completion of a well. Water is pumped into the well at a constant rate until a stable pressure is reached then the pump is turned off and the rate at which pressure decreases is measured. The pressure measurements are graphed and well permeability can

450

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

451

The Role of Viscosity in TATB Hot Spot Ignition  

SciTech Connect

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

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

2011-08-02T23:59:59.000Z

452

Homogeneous Charge Compression Ignition Free Piston Linear Alternator  

SciTech Connect

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

453

A sensitive neutron spectrometer for the National Ignition Facility  

SciTech Connect

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

454

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

SciTech Connect

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 gamma-ray dose to various components of the device. Specifications of the plasma-shaping coil, the shielding, coaling, requirements, and heating modes are given. 61 refs., 92 figs., 30 tabs. (WRF)

Henning, C.D.; Logan, B.G.; Barr, W.L.; Bulmer, R.H.; Doggett, J.N.; Johnson, B.M.; Lee, J.D.; Hoard, R.W.; Miller, J.R.; Slack, D.S.

1985-11-01T23:59:59.000Z

455

Initiation of ignition of a combustible gas mixture in a closed volume by the radiation of a high-power pulsed CO{sub 2} laser  

SciTech Connect

The results of experiments on initiating the ignition of a CH{sub 4} - O{sub 2} - SF{sub 6} triple gas mixture in a closed volume by the radiation of a high-power CO{sub 2} laser are presented. It is shown that spatially nonuniform (in the direction of the laser beam) gas heating by the laser radiation leads to formation of a fast combustion wave, propagating along the chamber axis and giving rise to 'instantaneous' ignition. At the threshold value 16.5 J of the laser radiation energy the fast combustion wave is transformed into a detonation wave, which causes an explosion and destruction of the reaction chamber.

Kazantsev, S Yu; Kononov, I G; Kossyi, I A; Popov, N A; Tarasova, N M; Firsov, K N

2012-01-31T23:59:59.000Z

456

Study of Rayleigh–Taylor growth in laser irradiated planar SiO{sub 2} targets at ignition-relevant conditions  

SciTech Connect

Rayleigh–Taylor (RT) growth experiments were performed on the OMEGA laser [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] using planar SiO{sub 2} targets seeded with a single mode 60-?m wavelength perturbation driven at peak laser intensities up to 9 × 10{sup 14} W/cm{sup 2}. These are the first RT measurements in SiO{sub 2} at conditions relevant to direct-drive inertial confinement fusion ignition. The measured average modulation growth rates agree with the 2-D hydrodynamics code DRACO, providing an important step in the development of target ablators that are robust to RT growth and hot- electron preheat considerations when driven at the intensities required to achieve thermonuclear ignition.

Hager, J. D.; Collins, T. J. B.; Knauer, J. P.; Meyerhofer, D. D.; Sangster, T. C. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States)] [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); Smalyuk, V. A. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)] [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

2013-07-15T23:59:59.000Z

457

Experimental Investigation of Effect of Injection Parameters...  

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

EGR p-32patel.pdf More Documents & Publications An Experimental Investigation of the Origin of Increased NOx Emissions When Fueling a Heavy-Duty Compression-Ignition Engine with...

458

The National Ignition Facility: the path to a carbon-free energy future  

Science Journals Connector (OSTI)

...basic science and fusion energy. One of the...achieving laboratory-scale thermonuclear ignition and energy...feasibility of laser fusion as a viable source of...achieving laboratory-scale thermonuclear ignition and energy...feasibility of laser fusion as a viable source of...

2012-01-01T23:59:59.000Z

459

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

460

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

E-Print Network (OSTI)

, Cambridge, MA 02139, USA 2 Lawrence Livermore National Laboratory, Livermore, CA 94550, USA 3 LaboratoryDiagnosing implosion performance at the National Ignition Facility (NIF) by means of neutron.1088/0029-5515/53/4/043014 Diagnosing implosion performance at the National Ignition Facility (NIF) by means of neutron spectrometry J

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461

Jet Ignition Research for Clean Efficient Combustion Engines Prasanna Chinnathambi, Abdullah Karimi, Manikanda Rajagopal, Razi Nalim  

E-Print Network (OSTI)

-chamber internal combustion engines and in innovative pressure-gain combustors for gas turbine engines. Jet engines using low-cost, low-carbon natural gas need improved methods for ignition of lean mixtures rotor combustor. A wave rotor combustion chamber is best ignited with a jet of hot gas that may come

Zhou, Yaoqi

462

The effect of monsoonal atmospheric moisture on lightning fire ignitions in southwestern North America  

E-Print Network (OSTI)

atmospheric moisture and precipitation. Using 16 years of lightning flash, relative humidity), on observed lightning fire data. The probability that a lightning flash would ignite an observed fireThe effect of monsoonal atmospheric moisture on lightning fire ignitions in southwestern North

Stephens, Scott L.

463

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

SciTech Connect

The primary goal of the Wildfire ignition resistant home design(WIRHD) program was to develop a home evaluation tool that could assess the ignition potential of a structure subjected to wildfire exposures. This report describes the tests that were conducted, summarizes the results, and discusses the implications of these results with regard to the vulnerabilities to homes and buildings.

Quarles, Stephen, L.; Sindelar, Melissa

2011-12-13T23:59:59.000Z

464

A comparison of various models in predicting ignition delay in single-particle coal combustion  

E-Print Network (OSTI)

A comparison of various models in predicting ignition delay in single-particle coal combustion November 2013 Accepted 7 January 2014 Available online xxxx Keywords: Coal Devolatilization Ignition delay a b s t r a c t In this paper, individual coal particle combustion under laminar conditions

465

Implosion hydrodynamics of fast ignition targetsa... R. B. Stephens,1,b  

E-Print Network (OSTI)

. In the initial concept2 the ignition pulse is provided by an ultrahigh-intensity laser that bores into the lowerImplosion hydrodynamics of fast ignition targetsa... R. B. Stephens,1,b S. P. Hatchett,2 M. Tabak,2 National Laboratory, Livermore, California 94550 3 Laboratory for Laser Energetics, University of Rochester

466

Integrated Fast Ignition Simulation of Cone-guided Target with Three Codes  

E-Print Network (OSTI)

. #12;Then an ultrahigh intense ignition laser is launched into the plasma, and we can simulate laserIntegrated Fast Ignition Simulation of Cone-guided Target with Three Codes H. Sakagami1) , T, Himeji, Hyogo 671-2201 Japan 2) Institute of Laser Engineering, Osaka University, 2-6 Yamadaoka, Suita

Paris-Sud XI, Université de

467

Initial cone-in-shell fast-ignition experiments on OMEGAa) W. Theobald,1,b)  

E-Print Network (OSTI)

-intense, high-energy laser pulse. Fast ignition relies on the localized deposition of the particle energyInitial cone-in-shell fast-ignition experiments on OMEGAa) W. Theobald,1,b) A. A. Solodov,1 C. Sinenian,3 T. Ma,6,7 F. N. Beg,7 E. Giraldez,8 and R. B. Stephens8 1 Laboratory for Laser Energetics

468

IMPLODING IGNITION WAVES. I. ONE-DIMENSIONAL ANALYSIS  

SciTech Connect

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

469

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

470

Optical and electrical investigations into cathode ignition and diode closure  

SciTech Connect

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

471

Visualization of Target Inspection data at the National Ignition Facility  

SciTech Connect

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

Potter, D; Antipa, N

2012-02-16T23:59:59.000Z

472