This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Diluents and Lean Mixture Combustion Modeling for SI Engines with a Quasi-Dimensional Model
Annotation ability available
Sector:
Language:
English
Abstract
Lean mixture combustion might be an important feature in the next generation of SI engines, while diluents (internal and external EGR) have already played a key role in the reductions of emissions and fuel consumption. Lean burn modeling is even more important for engine modeling tools which are sometimes used for new engine development. The effect of flame strain on flame speed is believed to be significant, especially under lean mixture conditions. Current quasi-dimensional engine models usually do not include flame strain effects and tend to predict burn rate which is too high under lean burn conditions. An attempt was made to model flame strain effects in quasi-dimensional SI engine models. The Ford model GESIM (stands for General Engine SIMulation) was used as the platform. A new strain rate model was developed with the Lewis number effect included. A 2.5L V6 4-valve engine and a 4.6L V8 2-valve modular engine were used to validate the modified turbulent entrainment combustion model in GESIM. Results showed that current GESIM can differ by as much as 10 crank angle degrees compared with test data. The modified GESIM can predict burn duration to within 1-2 CA of experimental data, which is considered very good for engine models. This improvement will make quasi-dimensional engine models such as GESIM more predictive and enhance its, applications in new engine development.
Recommended Content
Authors
Topic
Citation
Dai, W., Davis, G., Hall, M., and Matthews, R., "Diluents and Lean Mixture Combustion Modeling for SI Engines with a Quasi-Dimensional Model," SAE Technical Paper 952382, 1995, https://doi.org/10.4271/952382.Also In
References
- Khalighi, B. Tahry, S.H. Haworth, D.C. Huebler, M.S. “Computation and Measurement of Flow and Combustion in a Four-Valve Engine with Intake Variations,” SAE Paper 950287
- Tabaczynski, R.J. Ferguson, C.R. Radhakrishnan K. “A Turbulent Entrainment Model for SI Engine Combustion” SAE Paper 770647
- Davis, G.C. Kent, J.C. “Comparison of Model Calculations and Experimental Measurements of the Bulk Cylinder Flow Processes in a Motored PROCO Engine,” SAE Paper 790296
- Borgnakke, C. Davis, G.C. Tabaczynski, R.J. “Predictions of In-Cylinder Swirl Velocity and Turbulence Intensity for an Open Chamber Cup-in-Piston Engine,” SAE Paper 810224
- Newman, C.E. Davis, G.C. “GESIM Operation Theory” Ford Motor Co Research Report 1994
- Rutland, C.J. Trouve, A. “Direct Simulations of Premixed Turbulent Flames with Nonunity Lewis Numbers,” Combustion and Flame 94 41 57 1993
- Lewis, B. von Elbe, G. “Combustion, Flames and Explosion of Gases,” 220 261 Academic NY 1961
- Karlovitz, B. Denniston, D.W. Knapschaefer, D.H. Wells, F.E. Fourth Symposium (International) on Combustion 613 The Combustion Institute 1953
- Markstein, G. “Nonsteady Flame Propagation,” 5 73 MacMillan, NY 1964
- Law, C.K. “Dynamics of Stretched Flames,” 22nd Symposium (International) on Combustion The Combustion Institute Pittshburgh 1381 1402 1988
- Chung, S.H. Law, C.K. “An Integral Analysis of the Structure and Propagation of Stretched Premixed Flames” Combustion and Flame 72 325 336 1988
- Bradley, D. Lung, F.K-K. “Spark Ignition and the Early Stages of Turbulent Flame Propagation,” Combustion and Flames 69 71 93 1987
- Tseng, L.-K. Ismail, M.A. Faeth, G.M. “Laminar Burning Velocities and Markstein Numbers of Hydrocarbon/Air Flames” Combustion and Flame 95 410 426 1993
- Law, C.K. Sung, C.J. Yu, G. Axelbaum, R.L. “On the Structural Sensitivity of Purely Strained Planar Premixed Flames to Strain Rate Variations” Combustion and Flame 98 139 154 1994
- Blint, R.J. “Stretch in Premixed Laminar Flames under IC Engine Conditions,” Combustion Science and Technology 75 115 128 1991
- Cant, R.S. Pope, S.B. Bray, K.N.C. “Modeling of Flamelet Surface-to-Volume Ratio in Turbulent Premixed Combustion,” 22nd Symposium (International) on Combustion The Combustion Institute Pittshburgh 791 799 1988
- Haworth, D.C. Drake, M.C. Pope, S.B. Blint, R.J. “The Importance of Time-Dependent Flame Structures in Stretched Laminar Flamelet Models for Turbulent Jet Diffusion Flames,” 22nd Symposium (International) on Combustion The Combustion Institute Pittshburgh 589 597 1988
- Chin, Y.W. Matthews, R.D. Nichols, S.P. “Use of Fractal Geometry to Model Turbulent Combustion in SI Engines” Combustion Science and Technology 8 1-6 1 30 1992
- Herweg, R. Maly, R.R. “A Fundamental Model for Flame Kernel Formation in S.I. Engines” SAE Paper 922243
- Eckert, E.R.G. Drake, R.M. “Analysis of Heat and Mass Transfer” 787 McGraw-Hill Inc. 1972
- Perry, J.H. “Chemical Engineer's Handbook” 4th McGraw-Hill 1963
- Rhodes, D.B. Keck, James “Laminar Burning Speed Measurements of Indolene-Air-Diluent Mixtures at High Pressure and Temperature” SAE Paper 850047
- Heywood, J.B. “Combustion Chamber Design for Optimum SI Engine Performance” International Association of Vehicle Design Congress Geneva, Switzerland February 22-24 1984
- Brehob D.D. Newman, C.E. “Monte Carlo Simulation of S.I. Engine Cycle by Cycle Variability using GESIM” SAE Paper 921652