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1D and 3D CFD Investigation of Burning Process and Knock Occurrence in a Gasoline or CNG fuelled Two-Stroke SI Engine
Published November 08, 2011 by Society of Automotive Engineers of Japan in Japan
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The paper presents a combined experimental and numerical investigation of a small unit displacement two-stroke SI engine operated with gasoline and Natural Gas (CNG).
A detailed multi-cycle 3D-CFD analysis of the scavenging process is at first performed in order to accurately characterize the engine behavior in terms of scavenging patterns and efficiency. Detailed CFD analyses are used to accurately model the complex set of physical and chemical processes and to properly estimate the fluid-dynamic behavior of the engine, where boundary conditions are provided by a in-house developed 1D model of the whole engine. It is in fact widely recognized that for two-stroke crankcase scavenged, carbureted engines the scavenging patterns (fuel short-circuiting, residual gas distribution, pointwise lambda field, etc.) plays a fundamental role on both of engine performance and tailpipe emissions.
In order to assess the accuracy of the adopted numerical approach, comparisons between numerical forecasts and experimental measurements of instantaneous in-cylinder pressure history for steady-state operations of the engine are at first performed and shown in the paper.
Subsequently, results from 3D simulations are used to improve the scavenging characterization within the 1D model, where particular emphasis is now devoted to the investigation of the knock occurrence. In order to limit the computational cost of the simulations, the activity is at first carried out within the experimental and 1D modeling frameworks, where a quasi-dimensional combustion and knock model is used.
The 1D model is used to compute a numerical knock index which can be useful to address the tuning of the spark advance, given a prescribed and controlled percentage of knock released heat. At the end of the simulation process, the 1D knock index is qualitatively compared to results from full 3D knocking analyses for different in-cylinder compositions and spark timings.
The intrinsic knock-resistance of the CNG fuel is finally numerically exploited, through variations of both compression ratio and spark advance.
CitationBozza, F., Gimelli, A., Fontanesi, S., and Severi, E., "1D and 3D CFD Investigation of Burning Process and Knock Occurrence in a Gasoline or CNG fuelled Two-Stroke SI Engine," SAE Technical Paper 2011-32-0526, 2011, https://doi.org/10.4271/2011-32-0526.
- Conti, L., Ferrera, M., Garlaseo, R., Volpi, E., Cornetti, G.M. “Rationale of Dedicated Low Emitting CNG Cars”, SAE Paper No. 932763
- Gimelli, A., Grassia, P., Migliaccio, M.no, Unich, A., “Sulla efficacia della regolamentazione del traffico dei veicoli con motori a c.i. nei centri urbani per il contenimento della produzione di inquinanti”, International Congress Energy and Enviromental, Capri, Italy, June 2002. (In Italian)
- Grechi, D., Santino, D., Monni, F., Picini, P., “Verso una mobilità pulita - emissioni inquinanti da veicoli a motore: dalla misure di concentrazione alle stime di impatto in area urbana”, ACI, Firenze. (In Italian)
- Leighton, S. R., Cebis, M. J., Southern, M. P., Ahern, S. R., Horner, L., “The OCP Small Engine Fuel Injection System for Future Two-Stroke Marine Engines”, SAE Paper 941687
- Duret, P., Ecomard, A., Audinet, M., “A New Two-Stroke Engine with Compressed Air Assisted Fuel Injection System for High Efficiency Low Emissions Applications”, SAE Paper 880176
- Nuti, M., Pardini, R., Caponi, D. “FAST Injection System: PIAGGIO Solution for ULEV 2T SI Engines”, SAE Paper 970362
- Payri, F., Galindo, J., Climent, H., Pastor, J. M., Gaia, C. “Optimization of the scavenging and injection processes of an air-assisted direct fuel injection 50 c.c. 2-stroke SI engine by means of modeling”, SAE Paper 2001-01-1814
- Atkar, A. S., Tandan, V. J., Rairikar, S. D., Nair, C. K. J., Chaudhari, M. K. “Development Aspects of Conversion of 2-stroke Gasoline Engine to Operate on Bi-fuel CNG and Dedicated CNG Mode”, SAE Paper 962477
- Shanmugam, P., Anbukarasu, A. S., Babu, Y. R, Harne, Vinay, Rairikar, S. D., Kavathekar, K. P., Thipse, S. S., Marathe, N., “Development of a 2-Stroke CNG Engine for 3-Wheeler Vehicle for the Indian Market”, SAE Paper 2009-26-0022
- Fontanesi, S., Gagliardi, V., Malaguti, S., and Mattarelli, E., “Multidimensional Cycle Analysis of a Novel 2-Stroke HSDI Diesel Engines”, SAE Paper 2007-01-0161. 2007
- Lavy, J., Angelberger, C. Guibert, P., Mokhtari, S., “Towards a Better Understanding of Controlled Auto-Ignition (CAI™) Combustion Process From 2-Stroke Engine Results Analyses”, SAE Paper 2001-01-1859
- Bozza, F., Tuccillo, R., de Falco, D., “A Two-Stroke Engine Model Based on Advanced Simulation of Fundamental Processes”, SAE paper 952139, SAE Int. Congr. & Exp., Milwaukee, WI, sett. 1995,.
- Bozza, F., Gimelli, A., Senatore, A., Caraceni, A., “A Theoretical Comparison of Various VVA Systems for Performance and Emission Improvements of SI Engines”, SAE Paper 2001-01-0671, 2001
- Bozza, F., Gimelli, A., Tuccillo, R., “The Control of a VVA Equipped SI-Engine Operation by Means of 1D Simulation and Mathematical Optimization”, SAE Paper 2002-01-1107, SAE Trans. Vol. 111, 2002
- Bozza, F. Gimelli, A., “A Comprehensive 1D Model for the Simulation of a Small-Size Two-Stroke Engine”, SAE Paper 2004-01-0999, SAE World Congress, Detroit, March 2004, pubblicato anche sul volume “Modeling of Spark-Ignition Engines”, SAE SP-1830, ISBN 0-7680-1366-6, pp. 165-177, e su SAE 2004 Transactions, Journal of Engines - section 3, vol. 113-3, pp. 758-770, ISBN 0-7680-1552-9, Luglio 2005.
- Bozza, F., Gimelli, A., Andreassi, L., Rocco, V., Scarcelli, R., “1D-3D Analysis of the Scavenging and Combustion Process in a Gasoline and Natural-Gas Fuelled Two-Stroke Engine”, SAE Paper 2008-01-1087, SAE World Congress, Detroit, April 2008, pubblicato anche sul volume “Modeling of SI and Diesel Engines, 2008”, pagg. 297-309, SAE SP-2156, ISBN 978-0-7680-1998-8.
- Miller, D.S., Internal Flow Systems, Second Edition, BHR Group Limited, 1990
- Bingham, J.F., and Blair, G.P. “An improved branched pipe model for multi-cylinder automotive engine calculations”, Proc. of Inst. of Mech. Eng., Vol. 199, No D1, 1985
- Blair, G.P., Lau, H. B., Cartwright, A., Raghunathan, B.D., and Mackey, D.O., “Coefficients of Discharge at the Apertures of Engines”, SAE Paper 952138, 1995.
- Mitianiec, W., and Bogusz, A., “Theoretical and Experimental Study of Gas Flow Through Reed Valve in a Two-Stroke Engine”, SAE Paper 961802, 1996
- Matthews, R.D., and Chin, Y.W., “A Fractal-Based SI Engine Model: Comparisons of Predictions with Experimental Data,” SAE Paper 910075, 1991.
- Yoshiyama, S., Tomita, E., Zhang, Z., Hamamoto, Y., “Measurements and Simulation of Turbulent Flame Propagation in a Spark Ignition Engine by Using Fractal Burning Model”, SAE Paper 2001-01-3603, SAE Trans. Vol. 110, 2001.
- Rhodes, D.B., and Keck, J.C., “Laminar Burning Speed Measurements of Indolene-Air-Diluent Mixtures at High Pressures and Temperature”, SAE Paper 850047, SAE Trans. Vol. 94, 1985.
- North, G.L., and Santavicca, D.A., “The Fractal Nature of Premixed Turbulent Flames”, Comb. Science and Tech., Vol. 72, pp. 215-232, 1990.
- Poulos, S.G., Heywood, G.B., “The Effect of Chamber Geometry on Spark-Ignition Engine Combustion”, SAE paper 830334, 1983.
- Bozza, F., Fontana, G., Galloni, E., Torella, E., “3D-1D Analyses of the Turbulent Flow Field, Burning Speed and Knock Occurrence in a Turbocharged SI Engine”, SAE Paper 2007-24-0029, ICE 2007 Congress, Capri, Settembre 2007, pubblicato anche su SAE 2007 Transaction, Journal of Engines - section 3, vol. 116, pp. 1495-1507, ISBN 978-0-7680-1982-7, 2008.
- Tanaka, S., Ayala, F., Keck, J., “A Reduced Chemical Kinetic Model for HCCI Combustion of Primary Reference Fuels”, Combustion & Flame, 132, pp. 219-239, 2003.
- Duclos, J.M., Zolver, M., and Baritaud, T. 1999. ‘3D modeling of combustion for DI-SI engines’, Oil & Gas Science and Technology - Rev.IFP, 54(2), pp. 259-264.
- Colin, O. and Benkenida, A. “The 3-Zones Extended CoherentFlame Model (ECFM3Z) for Computing Premixed/Diffusion Combustion” Oil & Gas Science and Technology - Rev. IFP, Vol. 59 (2004), No. 6, pp. 593-609
- Colin, O., Pires da Cruz, A. and Jay, S. 2004. ‘Detailed chemistry bases auto-ignition model including low temperature phenomena applied to 3D engine calculations’, Submitted in 30th Symposium (International) on Combustion, The Combustion Institute
- Blair, G.P., “Design and Simulation of Two-Stroke Engines”, SAE, Warrendale, PA, 1996
- Heywood, J.B. and Sher, E., “The Two-Stroke Cycle Engine”, SAE, Warrendale, PA, 1999.