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The Effect of Incomplete Fuel-Air Mixing on Spark-Ignited Flame Kernel Growth
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Abstract
Results from an experimental study of the effect of incomplete fuel-air mixing on spark-ignited flame kernel growth in turbulent propane-air mixtures are presented. The experiments were conducted in a turbulent flow system that allows for independent variation of flow parameters, ignition system parameters, and the degree of fuel-air mixing. Measurements were made at 1 atm and 300 K conditions. Five cases were studied; a premixed and four incompletely mixed cases with 6%, 13%, 24% and 33% RMS (root-mean-square) fluctuations in the fuel/air equivalence ratio. The overall fuel/air equivalence ratio was unity in all cases. The flow characteristics were measured by LDV. The RMS fluctuation in the fuel/air equivalence ratio was characterized using NO2-based laser induced fluorescence. High speed laser shadowgraphy at 4,000 frames-per-second was used to record flame kernel growth following spark ignition, from which the equivalent flame kernel radius as a function of time was determined. The effect of incomplete fuel-air mixing was evaluated in terms of the flame kernel growth rate, “cyclic” variations in the flame kernel growth, and the rate of misfire.
The results show that fluctuations in local mixture strength due to incomplete fuel-air mixing cause the flame kernel surface to become wrinkled and distorted; and that the amount of wrinkling increases as the degree of incomplete fuel-air mixing increases. Incomplete fuel-air mixing was also found to result in a significant increase in “cyclic” variations in the flame kernel growth. The average flame kernel growth rates for the premixed and the incompletely mixed cases were found to be within the experimental uncertainty except for the 33%-RMS-fluctuation case where the growth rate is significantly lower. The premixed and 6%-RMS-fluctuation cases had a 0% misfire rate. The misfire rates were 1% and 2% for the 13%-RMS-fluctuation and 24%-RMS-fluctuation cases, respectively; however, it drastically increased to 23% in the 33%-RMS-fluctuation case.
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Citation
Cho, Y. and Santavicca, D., "The Effect of Incomplete Fuel-Air Mixing on Spark-Ignited Flame Kernel Growth," SAE Technical Paper 932715, 1993, https://doi.org/10.4271/932715.Also In
References
- Amann, C. A. “Whither the Spark-ignition engine?,” 1984
- Heywood, J. B. Internal Combustion Engine Fundamentals McGraw-Hill 1988
- Cho, Y. S. Santavicca, D. A. Sonntag, R. M. “The effect of Spark Power on Spark-ignited Flame Kernel Growth,” SAE Paper 922168 1992
- Nakamura, N. Kobayashi, T. Hanaoka, M. Takagi, N. “A New Platinum Tipped Spark Plug Extends the Lean Misfire Limit,” SAE Paper 830479 1983
- Pischinger, S. Heywood, J. B. “How Heat Losses to the Spark Plug Electrodes Affect Flame Kernel Development in an SI-Engine,” SAE Paper 900021 1990
- Tanuma, T. et al. “Ignition Combustion, and Exhaust Emissions of Lean Mixtures in Automotive Spark Ignition Engines,” SAE Paper 710159 1971
- Anderson, R. W. Asik, J. R. “Ignitability Experiments in a Fast Burn, Lean Burn Engine,” SAE Paper 830477 1983
- Anderson, R. W. Asik, J. R. “Lean Air-Fuel Ignition System Comparison in a Fast-Burn Engine,” SAE Paper 850076 1985
- Pischinger, S. Heywood, J. B. “A Study of Flame Development and Engine Performance with Breakdown Ignition Systems in a Visualization Engine,” SAE Paper 880518 1988
- Anderson, R. W. “The Effect of Ignition System Power on Fast Burn Engine Combustion,” SAE Paper 870549 1987
- Asik, J. R. et al. “Design of a Plasma Jet Ignition System for Automotive Application,” SAE Paper 770355 1977
- Nakai, M. Nakagawa, Y. Hamai, K. Sone, M. “Stabilized Combustion in a Spark-ignited Engine through a Long Spark Duration,” SAE Paper 850075 1985
- Harrington, J. A. Shinsu, R. C. Asik, J. R. “A Study of Ignition System Effects on Power, Emissions, Lean Misfire Limit, and EGR Tolerance of a Single-Cylinder Engine - Multiple Spark versus Conventional Single Spark Ignition,” SAE Paper 740188 1974
- Kono, M. et al. “Spark Discharge Characteristics and Igniting Ability of Capacitor Discharge Ignition Systems,” Combust. Sci. and Tech. 19 13 18 1978
- Maly, R. Et al. “Prospects of Ignition Enhancement,” SAE Paper 830478 1983
- Maly, R. “Spark Ignition: Its Physics and Effect on the Internal Combustion Engine,” in: Fuel Economy: Road Vehicles Powered by Spark Ignition Engines Hillard J. C. Springer G. S. Plenum Press 1984
- Ziegler, G. F. W. et al. “Influence of a Breakdown Ignition System on Performance and Emission Characteristics,” SAE Paper 840992 1984
- Ho, C. M. Santavicca, D. A. “Turbulence Effects in Early Flame Kernel Growth,” SAE Paper 872100 1987
- Peters, B. D. Quader, A. A. “Wetting” the Appetite of Spark Ignition Engines for Lean Combustion,” SAE Paper 780234 1978
- Pundir, B. P. Zvonow, V. A. Gupta, C. P. “Effect of Charge Non-Homogeneity on Cycle-by-Cycle Variations in Combustion in SI Engines,” SAE Paper 810774 1981
- Kajitani, S. Sawa, N. Rhee, K. T. “Mixture Preparation in Spark-ignition Engine and its Effect on Engine Performance and Combustion Characteristics,” SAE Paper 900711 1990
- Sztenderowicz, M. L. Heywood, J. B. “Mixture Nonuniformity Effects in S.I. Engine Combustion Variability,” SAE Paper 902142 1990
- Daniels, C. H. Evers, L. W. Han Z “Evaluating the Influence of Fuel Preparation on the Performance of a Spark-ignited Engine,” July 1991
- Gulati, A. Warren, R. E. Jr. “NO 2 -Based Laser-induced Fluorescence (LIF) Technique to Measure Cold-Flow Mixing,” AIAA 30th Aerospace Sciences Meeting & Exhibit Jan. 1992
- Kadota, T. “The Application of Laser Rayleigh Scattering to the Local Mixture Strength Measurements in SI Engine during Intake Stroke,” SAE Paper 872151 1987
- Kadota, T. Satoh, T. Memon, M. A. Sumida, O. “Mixture Strength Measurements in the Combustion Chamber of SI Engine via Rayleigh Scattering,” JSME (Int'l) Journal 32 1 134 141 1989
- Kadota, T. Zhao, F.-Q. Miyoshi, K. “Rayleigh Scattering Measurements of Transient Fuel Vapor Concentration in a Motored Spark Ignition Engine,” SAE Paper 900481 1990
- Zhao, F.-Q. Kadota, T. Takemoto, T. Temporal and Cyclic Fluctuation of Fuel Vapor Concentration in a Spark Ignition Engine,” SAE Paper 912346 1991
- Baritaud, T. A. Heinze, T. A “Gasoline Distribution Measurements with PLIF in a SI Engine,” SAE Paper 922355 1992
- Maly, R. R. et al. “Quantitative 2D LIF Measurements of Air/Fuel Ratios During the Intake Stroke in a Transparent SI Engine,” SAE Paper 922320 1992
- Shimizu, R. et al. “Measurement of Air-Fuel Mixture Distribution in a Gasoline Engine Using LIEF Technique,” SAE Paper 922356 1992
- Videto, B. D. Santavicca, D. A. “A Turbulent Flow System for Studying Turbulent Combustion Processes,” Combust. Sci. and Tech. 76 159 164 1991
- Eckbreth, A. C. “Laser Diagnostics for Combustion, Temperature and Species,” Energy and Engg. Science Series Gupta, A. K. Lilley, D. G. The Abacus Press 1988
- Tennekes, H. Lumley, J.L. A First Course In Turbulence The MIT Press 1972
- Huntzinger, G. O. Rigsby, G. E. “HEI - A New Ignition System Through New Technology,” SAE Paper 750346 1975
- Gordon, S. McBride, B. J. “Computer Program for Calculation of Complex Chemical Equilibrium Compositions, Rocket Performance, Incident and Reflected Shocks, and Chapman-Jouguet Detonations,” NASA SP-273 1986
- Metghalchi, M. Keck, J. C. “Burning Velocities of Mixtures of Air with Methanol, Isooctane, and Indolene at High Pressure and Temperature,” Combustion and Flame 48 191 210 1982
- Ryan, T. W. III Lestz, S. S. “The Laminar Burning Velocity of Isooctane, N-Heptane, Methanol, Methane, and Propane at Elevated Temperature and Pressures in the Presence of a Diluent,” SAE Paper 800103 1980
- Blint, R. J. “Flammability Limits for Exhaust Gas Diluted Flames,” GM Research Publication, GMR-6036 1988
- Metghalchi, M. Keck, J. C. “Laminar Burning Velocity of Propane-Air Mixtures at High Temperature and Pressure,” Combustion and Flame 38 143 154 1980
- Law, C. K. “Dynamics of Stretched, Flames,” 22nd Symposium (Int'l) on Combustion 1381 1402 1988
- Palm-Leis, A. Strehlow, R. A. “On the Propagation of Turbulent Flames,” Combustion and Flame 13 111 129 1969
- Strehlow, R. A. Combustion Fundamentals McGraw-Hill 1984
- Law, C. K. “A Compilation of Experimental Data on Laminar Burning Velocities,” 1992
- Weaver, C. E. Santavicca, D. A. “Correlation of Cycle-Resolved Flame Kernel Growth and Cylinder Pressure in an Optically-Accessible Engine,” SAE Paper 922171 1992
- Witze, P. O. Hall, M. J. Bennet M. J “Cycle-Resolved Measurements of Flame Kernel Growth and Motion Correlated with Combustion Duration,” SAE Paper 900023 1990
- Glassman, I. Combustion 2nd Academic Press, Inc. 1987
- Daneshyar, H. Hill, P. G. “The Structure of Small Scale Turbulence and Its Effect on Combustion in Spark Ignition Engines,” Prog. Energy Combust. Sci. 13 47 73 1987
- Bradley, D. Hynes, J. Lawes, M. Sheppard, C. G. W. “Limitations to Turbulence-Enhanced Burning Rates in Lean Burn Engines,” Proc. of the Inst. of Mech. Engr., International Conference 1988
- Hall, M. J. Bracco, F. V. “A Study of Velocities and Turbulence Intensities Measured in Firing and Motored Engines,” SAE Paper 870453 1987
- Baritaud, T. A. “Combustion and Fluid Dynamic Measurements in a Spark Ignition Engine: Effects of Thermochemistry and Velocity Field; Turbulent Flame Speeds,” SAE Paper 892098 1989
- Smith, J. R. “The Influence of Turbulence on Flame Structure in an Engine,” A.S.M.E. Conf. Phoenix, Arizona Nov. 14-19 1982
- Witze, P. O. Vilchis, F. R. “Stroboscopic Laser Shadowgraphy Study of the Effect of Swirl on Homogeneous Combustion in a Spark-Ignition Engine,” SAE Paper 810226 1981