This content is not included in your SAE MOBILUS subscription, or you are not logged in.
3D CFD Analysis of the Influence of Some Geometrical Engine Parameters on Small PFI Engine Performances - The Effects on Tumble Motion and Mean Turbulent Intensity Distribution
ISSN: 0148-7191, e-ISSN: 2688-3627
Published October 23, 2012 by SAE International in United States
Annotation ability available
In scooter/motorbike engines coherent and stable tumble motion generation is still considered an effective mean in order to both reduce engine emissions and promote higher levels of combustion efficiency. The scientific research also assessed that squish motion is an effective mean for speeding up the combustion in a combustion process already fast. In a previous technical paper the authors demonstrated that for an engine having a high C/D ratio the squish motion is not only not necessary but also detrimental for the stability of the tumble motion itself, because there is a strong interaction between these two motions with the consequent formation of secondary vortices, which in turn penalizes the tumble breakdown and the turbulent kinetic energy production.
The present paper starts with the development of a theoretical model which will be applied to different engine classes demonstrating how the relative importance of the tumble and squish varies changing the typical design parameters. The final achievements will be to show that the squish flow importance in promoting the turbulence reduces moving to small bore square engines. CFD simulation of the intake flow will be then performed with AVL Fire v. 2010 for investigating in more detail the stroke influence on the in-cylinder turbulence generation.
CitationFalfari, S., Bianchi, G., and Nuti, L., "3D CFD Analysis of the Influence of Some Geometrical Engine Parameters on Small PFI Engine Performances - The Effects on Tumble Motion and Mean Turbulent Intensity Distribution," SAE Technical Paper 2012-32-0096, 2012, https://doi.org/10.4271/2012-32-0096.
- Bianchi, G.M. Cantore, G. Nicolini, D. Sassi, L. Fraboni, L. “Numerical Analysis of the Influence of the Stroke-to-Bore Ratio on Tumble Breakdown” Proceedings of the 4th International Conference ICE 1999 September 1999 Capri
- Blaxill, H. Downing, J. Seabrook, J. Fry, M. “A Parametric Approach to Spark-Ignition Engine Inlet-Port Design,” SAE Technical Paper 1999-01-0555 1999 10.4271/1999-01-0555
- Gaikwad, S. Arora, K. Korivi, V. Cho, S. “Steady and Transient CFD Approach for Port Optimization,” SAE Int. J. Mater. Manuf. 1 1 754 762 2009 10.4271/2008-01-1430
- Lee, K. Bae, C. Kang, K. “The effects of tumble and swirl flows on flame propagation in a four valve S.I. engine” Applied Thermal Engineering 27 2007 2122 2130
- Ramajo, D. Zanotti, A. Nigro, N. “Assessment of a zero-dimensional model of tumble in four-valve high performance engine” International Journal of Numerical Methods for Heat & Fluid Flow 17 8 2007 770 787
- Laget, O. Zaccardi, J. Gautrot, X. Mansion, T. et al. “Establishing New Correlations Between In-Cylinder Charge Motion and Combustion Process in Gasoline Engines Through a Numerical DOE,” SAE Int. J. Engines 3 1 183 201 2010 10.4271/2010-01-0349
- Amer, A. Reddy, T. “Multidimensional Optimization of In-Cylinder Tumble Motion for the New Chrysler Hemi,” SAE Technical Paper 2002-01-1732 2002 10.4271/2002-01-1732
- Church, W. Farrell, P. “Effects of Intake Port Geometry on Large Scale In-Cylinder Flows,” SAE Technical Paper 980484 1998 10.4271/980484
- Miller, R. Newman, C. Dai, W. Trigui, N. et al. “Up-Front Prediction of the Effects of Cylinder Head Design on Combustion Rates in SI Engines,” SAE Technical Paper 981049 1998 10.4271/981049
- Baby, X. Floch, A. “Investigation of the In-Cylinder Tumble Motion In a Multi-Valve Engine: Effect of the Piston Shape,” SAE Technical Paper 971643 1997 10.4271/971643
- Arcoumanis, C. Godwin, S. Kim, J. “Effect of Tumble Strength on Combustion and Exhaust Emissions in a Single-Cylinder, Four-Valve, Spark-Ignition Engine,” SAE Technical Paper 981044 1998 10.4271/981044
- Mittal, M. Schock, H. “A Study of Cycle-to-Cycle Variations and the Influence of Charge Motion Control on In-Cylinder Flow in an IC Engine” ASME 2010 Journal of Fluids Engineering 132 051107-1
- Huang, R.F. Lin, K.H. Yeh, C.-N. Lan, J. “In-cylinder tumble flows and performance of a motorcycle engine with circular and elliptic intake ports” Journal of Experiments in Fluids 46 1 January 2009 165 179
- Murali Krishna, B. Mallikarjuna “Comparative study of in-cylinder tumble flows in an internal combustion engine using different piston shapes - an insight using particle image velocimetry” Journal of Experiments in Fluids 48 5 May 2010 863 874
- Lee, K.H. Lee, C.S. “Effects of tumble and swirl flows on turbulence scale near top dead centre in a four-valve spark ignition engine” Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 2003 217 607
- Achuth, M. Metha, P.S. “Predictions of tumble and turbulence in four-valve pent roof spark ignition engines” Int. Journal of Engine Research 2001 2 209
- Ueda, T. Okumura, T. Sugiura, S. Kojima, S. “Effects of Squish Area Shape on Knocking in a Four-Valve Spark Ignition Engine,” SAE Technical Paper 1999-01-1494 1999 10.4271/1999-01-1494
- Fujimoto, M. Iwai, K. Kataoka, M. Tabata, M. “Effect of combustion chamber shape on tumble flow, squish-generated flow and burn rate” Elsevier JSAE review 23 2002 291 296
- Berntsson, A. Josefsson, G. Ekdahl, R. Ogink, R. et al. “The Effect of Tumble Flow on Efficiency for a Direct Injected Turbocharged Downsized Gasoline Engine,” SAE Int. J. Engines 4 2 2298 2311 2011 10.4271/2011-24-0054
- Leiber, S. Schabetsberger, T. Schögl, O. Edtmayer, H. et al. “Design of a Tumble-Orientated Intake Port Layout for a Gasoline Combustion Process Used in Power Sport Application,” SAE Technical Paper 2011-32-0589 2011
- Adomeit, P. Jakob, M. Pischinger, S. Brunn, A. et al. “Effect of Intake Port Design on the Flow Field Stability of a Gasoline DI Engine,” SAE Technical Paper 2011-01-1284 2011 10.4271/2011-01-1284
- Falfari, S. Bianchi, G.M. Nuti, L. “Numerical Comparative Analysis of In-Cylinder Tumble Flow Structures in Small PFI Engines Equipped by Heads Having Different Shapes and Squish Areas” ICES2012-81095, ASME Internal Combustion Engine Division, 2012 Spring Technical Conference May 6 9 2012 Torino, Italy