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Correlation between Spark Ignition Characteristics and Flame Development in a Constant-Volume Combustion Chamber
ISSN: 0148-7191, e-ISSN: 2688-3627
Published February 01, 1992 by SAE International in United States
Annotation ability available
The electrical characteristics of transistorized coil ignition (TCI) and capacitor discharge ignition (CDI) systems were investigated in spark-ignited quiescent and flowing propane/air mixtures within an optically-accessible, cylindrical constant-volume combustion chamber. Under quiescent flow conditions, the initial pressure, temperature and equivalence ratio of the mixture as well as the spark gap width and geometry were varied systematically in order to examine the relationship between ignition characteristics and flame initiation and development. The effect of the flow in the spark gap on the electrical characteristics of the ignition system, mixture ignitability and flame development was also examined by varying the pre-ignition mean flow and turbulence as well as the spark plug orientation relative to the mean flow.
Under quiescent flow conditions and despite differences in the electrical characteristics of the two ignition systems examined, TCI and CDI gave rise to similar flame development which implies the absence of a correlation between breakdown/total energy and early flame development; the TCI system, however, with its longer spark duration and higher breakdown energy, allowed extension of the lean ignition limit especially at large spark gaps. For a given ignition system, lower initial mixture pressure, higher initial temperature and wider spark gaps resulted in faster flame propagation.
Under flowing mixture conditions, combustion duration was shortened and the lean limit was extended when the mean flow and turbulence in the spark gap were high provided the orientation of the ground electrode was not in the upwind side of the mean flow direction. As the flow velocities were reduced, the effect of spark plug orientation on ignitability became smaller.
IN SPARK-IGNITION ENGINES, the mechanism of transferring electrical energy from a given ignition system into the mixture in the spark gap is controlled by the thermodynamics of the mixture, the local flow characteristics and the spark plug geometry, e.g.[1,2].* The net total energy deposited into the mixture during the ignition process, which is a fraction of the energy supplied by the spark, and the rate of deposition affect the early flame development which, in turn, is correlated with the burn duration in both quiescent and flowing gasoline/air mixtures.
The ignition criteria vary between quiescent and flowing mixtures. In quiescent mixtures, the energy supplied by the ignition system per unit mixture volume per unit time and the energy deposition duration are the determining factors while in flowing mixtures the above criteria become a function of the mixture velocity in the vicinity of the spark plug. This uncertainty concerning the amount of energy actually deposited into the mixture is creating difficulties in interpreting data in the literature which are mainly based on the energy available in the ignition system.
Understanding the mechanism of energy transfer into the mixture during the three discharge modes of the ignition process [2,3] and the associated energy losses from the early flame kernel to the electrodes [4,5], requires simultaneous measurement on a cycle-to-cycle basis of the time-resolved voltage and current during discharge, of the local flow and mixture strength in the spark gap and of the kernel/flame development in the combustion chamber over a wide range of engine operating conditions. Due to the difficulties involved in performing such simultaneous multi-parameter experiments, engine researchers have attempted to isolate the effects of mixture and flow variations on flame initiation and propagation by examining quiescent or well-premixed mixtures in constant-volume chambers [6,7] and performing experiments in well-characterised engine geometries [8,9].
Along these lines, the present study examines the relationship between the electrical characteristics of spark ignition and flame development in quiescent and flowing propane/air mixtures based on single-shot measurements of electrical characteristics, flame propagation speed and pressure in a constant-volume chamber using transistorized coil ignition (TCI) and capacitor discharge ignition (CDI) systems. The varying energies, discharge periods and associated discharge efficiencies of these two systems allow investigation of the cause and effect relationship between electrical characteristics and flame initiation and propagation.
The present investigation was considered necessary prior to attempting correlation studies in a high-turbulence, four-valve spark-ignition engine in order to allow a reduction of the parameters of interest and better focussing on the lean-burn limit where the problems of misfire and increased cyclic variations and unburned hydrocarbon emissions are still unresolved.
The constant-volume chamber and the experimental techniques employed to characterise the ignition system, flame initiation and development are described in the next section followed by discussion of the results and conclusions.
CitationArcoumanis, C. and Bae, C., "Correlation between Spark Ignition Characteristics and Flame Development in a Constant-Volume Combustion Chamber," SAE Technical Paper 920413, 1992, https://doi.org/10.4271/920413.
- Lewis, B.L. von Elbe, G. “Combustion,Flames and Explosion of Gases” Academic Press New York 2nd 1961
- Maly, R.R. “Spark Ignition; its Physics and Effect on the Internal Combustion Process” Ch.3 in ‘Fuel Economy in Road Vehicles Powered by Spark Ignition Engines’ Hilliard J.C. Springer G.S. Plenum New York 1984
- Ballal, D.R. Lefebvre, A.H. “The Influence of Spark Discharge Characteristics on Minimum Ignition Energy in Flowing Gases” Combustion and Flame 24 1975
- Ko, Y. Anderson, R.W. “Electrode Heat Transfer during Spark Ignition” SAE paper 892083 1989
- 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
- Binder, K. Maly, R.R. “Effects of Ignition and Turbulence on Flame Speed at High Pressures and Temperatures” Proc.XXI FISITA Congress,Paper 865036 1986
- Lim, M.T. Anderson, R.W. Arpaci, V.S. “Prediction of Spark Kernel Development in Constant Volume Combustion” Combustion and Flame 69 1987
- Pischinger, S. Heywood, J.B. “A Study of Flame Development and Engine Performance with Break-down Ignition Systems in a Visualization Engine” SAE Paper 880518 1988
- Bianco, Y. Cheng, W.K. Heywood, J.B. “The effects of Initial Flame Kernel Conditions on Flame Development in SI Engine” SAE Paper 912402 1991
- Metghalchi, M. Keck, J.C. “Laminar Burning Velocity of Propane-Air Mixtures at High Temperature and Pressure” Combustion and Flame 38 1980
- Swords, M.D. Kalghatgi, G.T. Watts, A.J. “An Experimental Study of Ignition and Flame Development in a Spark Ignition Engine” SAE Paper 821220 1982
- Foster, D.E. Witze, P.O. “A Comparison of Flame Detection Techniques for Premixed-Charge Combustion in Spark Ignition Engines” Experiments in FIuids 6 1988
- Gaydon, A.G. Wolfhard, H.G. “Flames; their Structure,Radiation and Temperature” Chapman and Hall 4th 1979
- Steiner, J.C. Mirsky, W. “Experimental Determination of the Dependence of the Minimum Spark Ignition Energy upon the Rate of Energy Release” SAE Paper 660346 1966
- Ziegler, G.F.W. Wagner, E.P. Maly, R.R. “Ignition of Lean Methane-Air Mixtures by High Pressure Glow and Arc Discharges” 20th Symposium on Combustion 1984
- Nasser, E. “Fundamentals of Gaseous Ionization and Plasma Electronics” John Wiley and Sons 1971
- Bae, C-S. “Correlation between Ignition Characteristics,Flow and Flame Development in Spark-Ignited Premixed Mixtures” Ph.D. Thesis Imperial College
- Kono, M. Inuma, K. Sakai, T. Kumagai “Spark Discharge Characteristics and Ignition Ability of Capacitor Discharge Ignition Systems” Comb.Sci.Tech. 19 1978
- Hood, S. “The V-Grooved Electrode Spark Plug” SAE Paper 901535 1990
- Kono, M. Kumagai, S. Sakai, T. “Ignition of Gases by Two Successive Sparks with reference to Frequency Effect of Capacitance Sparks” Combustion and Flame 27 1976
- Dugger, G.L. Heimel, S. “Flame Speeds and Methane-Air Propane-Air and Ethylene-Air Mixtures at Low Temperature” NACA TN2624 1952
- Hattori, T. Goto, K. Ohigashi, S. “Study of Spark Ignition in Flowing Lean Mixtures” IMechE Paper C101/79 1979
- Lefebvre, A.H. “Gas Turbine Combustion” McGraw-Hill 1983
- Ko, Y. Anderson, R.W. Arpaci, V.S. “Spark Ignition of Propane-Air Mixtures Near the Minimum Ignition Energy: Part I. An Experimental Study” Combustion and Flame 83 1991
- Ko, Y. Arpaci, V.S. Anderson, R.W “Spark Ignition of Propane-Air Mixtures Near the Minimum Ignition Energy: Part II. A Model Development” Combustion and Flame 83 1991
- Gettel, L.G. Tsai, K.C. “The Effect of Enhanced Ignition on the Burning Characteristics of Methane-Air Mixtures” Combustion and Flame 54 1983
- Hancock, M.S. Buckingham, D.J. Belmont, M.R. “The Influence of Arc Parameters on Combustion in a Spark Ignition Engine” SAE Paper 860321 1986
- Hahn, J.P. Anderson, R.W. “Correlation of Fiber Optic Spark Plug and Combustion Pressure Data on Two- and Four-Valve per Cylinder Production Engines” Central States Meeting,Combustion Institute 1991
- Anderson, R.W. Asik, J.R. “Ignitability Experiments in a Fast Burn, Lean Burn Engine” SAE Paper 830477 1983