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Improvement and validation of a thermodynamic S.I. engine simulation code

By Ebrahim Abdi Aghdam


This study was concerned with improvement and validation of a thermodynamic spark ignition engine simulation code developed in Leeds.\ud \ud Experimental validation data were generated using a central ignition, disc-shaped combustion chamber variant of a ported single-cylinder research engine with full-bore\ud overhead optical access. These data included simultaneous measurement of cylinder pressure and flame position at different operating conditions. The engine was skip fired\ud (fired once every five cycles), to remove residuals and ensure well defined in-cylinder fuel-air mixture for simulation. Flames were imaged using a digital camera capturing the light emitted from the flame ("natural light").\ud \ud New methods were developed to process the pressure and film data. Flame pictures were processed to determine enflamed area, mean flame radius and flame centroid. Parameters were also developed to describe flame "circularity" ("shape factor") and to describe asymmetry of flame approach to the cylinder walls ("active perimeter fraction", APF). Time-base crank angle records allowed evaluation of engine speed\ud variation within a cycle and mean engine speed for a cycle.\ud \ud Although generated principally for model validation, the experimental results proved interesting in their own right. Middle, slow and fast cycles were defined for each condition. Analysis of these cycles suggested that there was no correlation between the initial flame centroid displacement, its locus over the flame propagation period or the flame "shape factor" and the speed of combustion and pressure development. As the flame approached the wall, the active perimeter fraction fell in a similar manner for all\ud the middle cycles.\ud \ud Substantial modifications were made to a pre-existing thermodynamic engine cycle code. Deficiencies in the blowby, heat transfer and thermodynamic aspects were\ud corrected. An additional ("Zimont") turbulent burning velocity sub-model and a new routine for the influence of engine speed variation within a cycle were incorporated into\ud the code. The active perimeter fraction parameter function determined in the experiments was encoded to allow for the effects of flame-wall contact on entrainment rate during the late flame propagation. A radial stratified charge model was also developed. Burned gas expansion over the flame propagation period was shown to significantly change the unburned gas charge stratification from the initial variation. Two types of initial stratification (linear and parabolic distributions, rich of the centre and lean close to the wall) were imposed. Faster combustion development was observed in both cases, c. f that for equivalent homogeneous charge.\ud \ud Good agreement was observed between experimental results and "Zimont model" predictions at different equivalence ratios and engine speeds. Other computations using\ud the pre-existing Leeds K and KLe correlations gave reasonable predictions at the various engine speeds and at rich conditions; however, they yielded slower results than\ud experimentally observed for lean conditions

Publisher: School of Mechanical Engineering (Leeds)
Year: 2003
OAI identifier:

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  1. (1972). A First Course in Turbulence.;
  2. (1997). A Hydrocarbon Autoignition Model for Knocking Combustion in SI Engines.; doi
  3. (1985). A Model for Predicting Spatially and Time Resolved Convective Heat Transfer in Bowl-in-Piston Combustion Chambers.; doi
  4. (1995). A Numerical Model of Premixed Turbulent Combustion.; Chemical Physics Reports 14,
  5. (1992). A Refinement of Flame Propagation Combustion Model for Spark-Ignition Engines.; doi
  6. (2000). A Semi-Empirical Model of Spark-Ignited Turbulent Flame Growth.; doi
  7. (1997). A simple Model of Unsteady Turbulent Flame Propagation.; SAE paper 972993. doi
  8. (1987). A study of doi
  9. (1996). A Study of Cycle-to-Cycle Variations in SI Engines Using a Modified Quasi-Dimensional Model. ; SAE paper 961187. doi
  10. (2000). A Three-Zone Heat Release Model for Combustion Analysis in a Natural Gas SI Engine -Effects of Crevices and Cyclic Variations on UHC Emissions.; doi
  11. (2002). Accuracy Limits of IMEP Determination from Crankshaft Speed Measurements.; doi
  12. (1981). An Experimental and Theoretical Study of the Combustion Process in a Divided Chamber Spark Ignition Engine.; PhD Thesis, doi
  13. (1996). An Investigation of a New Tvpe Direct-Injection Stratified Charge Combustion System for Gasoline Engines.; SAE paper 961150. doi
  14. (2003). Analysis of Cylinder Pressure and Flaute and Flame Development in S.
  15. (2000). Application of a New Technique for the Evaluation of Cycle-by-Cycle Variation doi
  16. (1997). Approximations for Burning Velocities and Markstein Numbers for Lean Hydrocarbon and Methanol Flames.; doi
  17. (2000). Aspects of Laminar and Turbulent Burning Velocity Relevant to SI Engines.; doi
  18. (1993). Autoignition and Knock Aerodynamics in Engine Combustion.; doi
  19. (1997). Autoignition and Knock in Spark Ignition Engines.; doi
  20. (1999). Automotive spark-ignition directinjection gasoline engines.;
  21. (1998). Combustion analysis and cycle-hr cycle variations in spark ignition engine combustion Part?: a new parameter for completeness of combustion and its use in modelling cycle-hi-cycle variations in combustion.; doi
  22. (2000). Combustion and the thermodynamic performance of spark ignition engines.; Proc Instn Mech Engrs, Vol 214, Part C,
  23. (1998). Combustion Characteristics of a Direct-Injection doi
  24. (1983). Combustion in a Dual Chamber Spark Ignition Engine.; PhD Thesis,
  25. (1987). Combustion, Flames and Explosions of Gases.; (third edition) doi
  26. (1993). Comparison of Measured and Predicted Combustion Characteristics of a Four-Valve S. doi
  27. (2000). Computational and Experimental Study of Flame Propagation in Radial Stratified Charge SI Engines.;
  28. (1969). Computing with Thermochemical Data.; doi
  29. (2000). Crank Angle Based Torque Estimation: Mechanistic/Stochastic,; doi
  30. (1990). Cycle-Resolved Measurements of Flame Kernel Growth and Motion Correlated with Combustion Duration.; doi
  31. (1994). Cyclic Variability in Spark Ignition Engines A Literature Sun'ev.; doi
  32. (1988). Cyclic Variation and Turbulence Structure in Spark-Ignition Engines.; doi
  33. (2000). Cyclically Resolved Simultaneous Flame and Flow Imaging in a SIEngine.; doi
  34. (1990). Cylinder-Pressure-Transducer Mounting Techniques to Maximize Data Accuracy.; doi
  35. (1999). Development of an Engine Simulation Program and Its Application to Stratified Charge SI Engines.; doi
  36. (1957). Effect of Initial Mixture Temperature on the Burning Velocity of Benzene-Air, n-Heptane-Air and Iso-octane-Air Mixtures.; doi
  37. (1999). End Gas Autoignition and Knock in Spark Ignition Engines.: doi
  38. (1994). End-Gas Autoignition Modes and Spark-Ignition Engine Knock Severity.; doi
  39. (1993). Engine Diagnostics by Dynamic Shaft Measurement: A Progress Report,; doi
  40. (2002). Engine LDA Technique Progress Report.; The
  41. (1987). Estimating Heat-Release and Mass-ofMixture Burned from Spark-Ignition Engine Pressure Data.; doi
  42. (1974). Experimental and Theoretical Investigation of Turbulent Burning Model for Internal Combustion Engines., SAE paper 740191. doi
  43. (1997). Experimental Study of Flow and Turbulence in aV -flame Burner and a SI Engine.;
  44. (1983). Experiments and a Correlation of Turbulent Burning Velocities.; doi
  45. (1992). Flame Stretch Rate as a Determinant of Turbulent Burning Velocity.; doi
  46. (1952). Flame Velocities of Hvdrocarhon-OrtgenNitrogen Mixtures.; Fourth Symposium (International) on combustion. doi
  47. (1994). Flow and Combustion in a FourValve Spark-Ignition Optical Engine.; SAE paper 940475. doi
  48. (1982). Flow in the Piston-Cvlincler-Ring Crevices of a Spark-Ignition Engine: Effect on Hydrocarbon Emissions, Efficiency and Power.; doi
  49. (2002). Fuel Sprat/ Simulation of Slit Nozzle Injector for Direct-Injection Gasoline Engine.; doi
  50. (1986). Fundamental Turbulent Combustion Problems Related to Gasoline Engines.; PhD Thesis,
  51. (2002). Gasdi'namics Modeling of Countergradient Transport doi
  52. (1993). Gasoline Engine Cvcle Simulation Using the Leeds Turbulent Burning Velocity Correlations.; SAE paper 932640. doi
  53. (1984). Heat Release Analysis from Pressure Data.; SAE paper 841359, doi
  54. (1990). How Heat Losses to the Spark Plug Affect Flame Kernel Development in an SI-Engine.; doi
  55. (1998). Imaging and Analysis of Turbulent Flame Development in SparkIgnition Engines.;
  56. (1995). Imaging and Thermodynamic Analysis of Autoignition and Knock
  57. (2002). In-ci'Iinder Turbulence Measurements with a Spark Plug-in Fiber LDV.;
  58. (1992). Influencing Parameters and Error Sources During Indication on Internal Combustion Engines.; doi
  59. (2000). Instantaneous Flow Field Effects on the Flame Kernel doi
  60. (1989). Internal Combustion Engine Modelling.;
  61. (1991). Introduction to internal combustion engines.; 2nd Edition,
  62. (1987). Laminar Burning Velocities of Iso-Octane-Air Mixtures -A Literature Review.; SAE paper 870170. doi
  63. (1982). Laminar Burning Velocities of Methanol, doi
  64. (1988). Limitations to Turbulence-Enhanced Burning Rates in Lean Burn Engines.;
  65. (1996). Local Charge Stratification doi
  66. (1985). Mechanics of Materials.; doi
  67. (1992). Modelling and Experimental Validation of Turbulent Flame Propagation in Spark Ignition Engines.;
  68. (1980). Modelling of fluid motion in engines- An introductory overview.; doi
  69. (1998). Models for the Prediction of Performance and Emissions in a Spark Ignition Engine -A Sequentially Structured Approach.; SAE paper 980779. doi
  70. (1983). Modes and Measures of Cyclic Combustion Variability.; doi
  71. (1992). Monte Carlo Simulation of Cycle bti" Ctrcle Variability.; SAE paper 922165. doi
  72. (1938). Motion Pictures of Engine Flames Correlated with Pressure Cards.; doi
  73. (1961). On the Flow of Gas Through the Piston-Rings (1st Report, The Discharge Coefficient and Temperature of Leakage Gas).; doi
  74. (1961). On the Flow of Gas Through the Piston-Rings (2nd Report, The Character of Gas Leakage).; doi
  75. (1994). Optimization of In-Cylinder Flow and Mixing for a Center-Spark Four-Valve Engine Employing the Concept of Barrel-Stratification.; doi
  76. (2003). PhD Thesis in progress,
  77. (1974). Piston Ring Lubrication and Cylinder Bore Wear Analysis.; Part I- Theory, doi
  78. (2001). Quantifying Relationship Between Crankshaft's Speed Variation and Gas Pressure Torque.; doi
  79. (1994). Quantitative Fuel Distribution in a Spark Ignition Engine, Measurement and Observation Analysis of Combustion in Engines.; IMech E-Seminar.
  80. (2000). Research and Development of a New Direct Injection Gasoline Engine.; doi
  81. (1966). The Computation of Apparent Heat Release for Internal Combustion Engine.;
  82. (1953). The Dynamics and Thermodynamics of Compressible Fluid Flow.: doi
  83. (1940). The Effect of Turbulence on Flame Velocity in Gas Mixtures.;
  84. (1995). The Effects of Bulk Motions and Turbulence oil Combustion
  85. (1997). The Importance of Turbulence Intensity. Eddy Size and Flame Size in Spark Ignited, Premixed Flame Growth. Technical Note, doi
  86. (2003). The Influence of Fuel Air Ratio on the Turbulent Burning Velocity of Iso-octane Air Flames.; Fourth International Seminar of Fire and Explosion Hazards,
  87. (1980). The Laminar Burning Velocity of Isooctane, doi
  88. (1998). The Measurement of Laminar Burning Velocities and Markstein Numbers for Isooctane-Air and Iso-octane-n-Heptane-Air Mixtures at Elevated Temperatures and Pressures in an Explosion Bomb.; Combustion and Flame 115, doi
  89. (1981). The Prediction of Gas Pressures Within the Ring Packs of Large Bore Diesel Engines.; doi
  90. (2002). The Volumetric Efficiency of Direct and Port Injection Gasoline Engines with Different Fuels.; doi
  91. (1979). Theory of Turbulent Combustion of a Homogeneous Fuel Mixture at High Reynolds Number.; doi
  92. (1999). Thernzodvncunic modelling of complete engine systems -a review. ;
  93. (1996). Tumble Flow and Turbulence Characteristics in a Small Four-Valve Engine.; SAE paper 960265. doi
  94. (1986). Turbulence Effects on Combustion in Spark Ignition Engines.. doi
  95. (1983). Turbulence Measurements and Modelling in Reciprocating Engines - an Overview.;
  96. (1984). Turbulent Burning Velocities and Flame Straining in Explosions.; doi
  97. (1987). Turbulent burning velocities: a general correlation in terms of straining rates.; doi
  98. (2003). Turbulent burning velocity, burned gas distribution, and associated flame surface definition., doi
  99. (2001). Turbulent Flame Development in a Spark Ignition Engine.; doi
  100. (1983). Turbulent Flame Propagation and Combustion in spark Ignition Engines.; doi
  101. (1998). Turbulent Flame Propagation in a Methane Fuelled Spark Ignition Engine.; doi
  102. (2002). Turbulent Flame Speed and Thickness: Phenomenology, Evaluation, and Application doi
  103. (1994). Turbulent Flame Structure and Autoignition in Spark Ignition Engines.; doi
  104. (1990). Turbulent Premixed Flame Propagation Models for Different Combustion Regimes. doi
  105. (1999). Two Heat Release Analysis of Combustion Data and Calibration of Heat Transfer Correlation in an I. doi
  106. (1996). Understanding the Thermodynamics of Direct Injection Spark Ignition (DISI) Combustion Systems: An Analytical and Experimental Investigation.; doi
  107. (2000). Visualization of the Qualitative Fuel Distribution and Mixture Formation Inside a Transparent doi

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