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Modeling Alternative Prechamber Fuels in Jet Assisted Ignition of Gasoline and LPG
ISSN: 0148-7191, e-ISSN: 2688-3627
Published April 20, 2009 by SAE International in United States
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Gas assisted jet ignition is a prechamber combustion initiation system for conventional spark ignition engines. With the system, a chemically active turbulent jet is used to initiate combustion in lean fuel mixtures enabling reliable combustion over a much broader range of air-fuel ratios. The extended range is due to the distributed ignition source provided by the jet, which can overcome the problems of poorly mixed main chamber charges and slower burning fuels. In addition, the ability to reliably ignite lean mixtures improves the thermal efficiency and enables ultra low emission levels.
Experiments together with flame propagation modeling completed using STAR-CD with CHEMKIN Kinetics were done in order to examine the effects of numerous prechamber fuels on the ignition of the main fuel, which consisted of either liquefied petroleum gas (LPG) or gasoline. The modeling and experimental results showed similar trends, with the modeling results giving insight into the physicochemical process by which main fuel combustion is initiated in the jet ignition process.
Both the modeling and experimental results indicate that the level of ignition enhancement provided by jet ignition is highly dependent on the generation of chemical species and not solely on the energy content of the prechamber fuel. In addition, the effects of the rich jet ignition prechamber are examined and reveal that the chemical properties of the rich prechamber jet are essential in promoting lean main chamber combustion in the jet ignition process and that the thermal and turbulence effects of the jet play only a secondary role.
Experimental and modeling results both showed that although hydrogen was the most effective prechamber fuel with this jet ignition process, especially when operating in the ultra lean region, other alternative fuels were effective at operating between λ=2-2.5. These lean limits are about twice the value possible with spark ignition (λ=1.25-1.4) in this engine at similar load conditions. In addition, the LPG results are very encouraging as they offer the possibility of a system similar to HAJI but using a commonly available fuel in both the main chamber and prechamber.
CitationToulson, E., Watson, H., and Attard, W., "Modeling Alternative Prechamber Fuels in Jet Assisted Ignition of Gasoline and LPG," SAE Technical Paper 2009-01-0721, 2009, https://doi.org/10.4271/2009-01-0721.
Multi-Dimensional Engine Modeling, 2009
Number: SP-2245; Published: 2009-04-20
Number: SP-2245; Published: 2009-04-20
- Dober G.G. Watson H.C. Modelling the Flame Enhancement of a HAJI Equipped Spark Ignition Engine IPC-10 Proceedings Paper Number 99091 1999
- Dale J.D. Oppenheim A.K. Enhanced Ignition for I.C. Engines with Premixed Gases SAE Transactions 90 paper 810146 1981
- Oppenheim A.K. ombustion in Piston Engines: Technology, Evolution, Diagnosis and Control 2004 New York Springer
- Heywood J.B. Internal Combustion Engine Fundamentals International ed. Automotive Technology Series 1988 McGraw-Hill
- Lawrence J. Hydrocarbon Emission from a HAJI Equipped Ultra Lean Burn Engine, PhD Thesis The Department of Mechanical Engineering 1999 The University of Melbourne
- Lawrence J. Watson H.C. Hydrocarbon Emissions from a HAJI Equipped Ultra-lean Burn SI Engine SAE Paper 980044 1998
- Lumsden G. Watson H.C. Optimum Control of and S.I. Engine with a Lambda=5 Capability SAE paper 950689 1995
- Tully E.J. Heywood J. Lean-Burn Characteristics of a Gasoline Engine Enriched with Hydrogen from a Plasmatron Fuel Reformer SAE 2003-01-0630 2003
- Toulson E. Applying Alternative Fuels in Place of Hydrogen to the Jet Ignition Process, PhD Thesis The Department of Mechanical Engineering 2009 The University of Melbourne
- Toulson E. Watson H.C. Attard W.P. Gas Assisted Jet Ignition of Ultra-Lean LPG in a Spark Ignited Engine SAE 2009-01-0506 2009
- CD-adapco STAR/KINetics: A New Tool For Reacting Flow Analysis CD-adapco Dynamics 2004
- Mehrani P. Watson H.C. Well-Stirred Reactor Assumption Applied to the Combustion Simulation for a HAJI Engine Operating Close to Knock Limit Combustion Science and Technology 2008
- Mehrani P. Flame Propagation and Knocking in a HAJI Engine, PhD Thesis The Department of Mechanical Engineering 2008 The University of Melbourne
- Hu H. Keck J.C. Autoignition of Adiabatically Compressed Combustible Gas Mixtures SAE Paper 872110 1987
- Tanaka S. Ayala F. Keck J.C. A Reduced Chemical Kinetic Model for HCCI Combustion of Primary Reference Fuels in a Rapid Compression Machine Combustion and Flame 2003 133 4 467 481
- Tanaka S. Ayala F. Keck J.C. Heywood J.B. Two-Stage Ignition in HCCI Combustion and HCCI Control by Fuels and Additives Combustion and Flame 2003 132 1-2 219 239
- Yelvington P.E. Design of a Viable Homogeneous-Charge Compression Ignition (HCCI) Engine: A Computational Study with Detailed Chemical Kinetics, PhD Thesis The Department of Chemical Engineering 2004 Massachusetts Institute of Technology
- Knop V. Jay S. Latest Developments in Gasoline Auto-Ignition Modelling Applied to an Optical CAI Engine Oil & Gas Science and Technology - Rev. IFP 2006 61 121 137
- Jachimowski C.J. Chemical Kinetic Reaction Mechanism for the Combustion of Propane Combustion and Flame 1984 55 2 213 224
- Toulson E. Watson H.C. Attard W.P. The Lean Limit and Emissions at Near-Idle for a Gasoline HAJI System with Alternative Pre-Chamber Fuels SAE 2007-24-0120 2007
- Toulson E. Watson H.C. Attard. W.P. The Lean Limit and Emissions of a Gasoline HAJI System that Employs Syngas in Place of Hydrogen as the Prechamber Fuel FISITA 2008 Paper F2008-SC-002 2008 Munich, Germany
- Hamori F. Experimental Combustion Burn Rate Analysis (E-CoBRA) 2005
- Lumsden G. The Phenomena of Hydrogen Assisted Jet Ignition, PhD Thesis The Department of Mechanical Engineering 1995 The University of Melbourne
- Babrausak V. Ignition Handbook 2003 Issaquah. WA Fire Science Publishers
- Phuong P.X. Comparison of Liquid and Gaseous Liquified Petroleum Gas Injection in a SI Engine, M Eng. Sci. Thesis The Department of Mechanical Engineering 2006 The University of Melbourne