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Engine Breathing - Steady Speed Volumetric Efficiency and Its Validity Under Transient Engine Operation
ISSN: 0148-7191, e-ISSN: 2688-3627
Published March 01, 1999 by SAE International in United States
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This paper questions whether the application of steady speed volumetric efficiency data to transient SI engine operation under WOT is a valid one. A state-of-the-art computer simulation model is used to compare steady speed volumetric efficiency with instantaneous values. A baseline engine model is first correlated with measured volumetric efficiency data to establish confidence in the engine model's predictions. A derivative of the baseline model, complete with variable geometry inlet manifold, is then subjected to a transient excursion simulating typical, in-service, maximum rates of engine speed change. Instantaneous volumetric efficiency, calculated over discrete engine cycles forming the sequence, is then compared with its steady speed counterpart at the corresponding speed. It is shown that the engine volumetric efficiency responds almost quasi-steadily under transient operation thus justifying the assumption of correlation between steady speed and transient data. The computer model is used to demonstrate the underlying gas dynamic phenomena graphically.
The paper provides a good example of the application of computer simulation techniques in providing answers to real engineering questions. In particular, the value of an in-depth analysis of fundamental physical phenomena characterising engine mass flow is demonstrated.
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CitationSmith, L., Fickenscher, T., and Osborne, R., "Engine Breathing - Steady Speed Volumetric Efficiency and Its Validity Under Transient Engine Operation," SAE Technical Paper 1999-01-0212, 1999, https://doi.org/10.4271/1999-01-0212.
- GT-Power V4.3, Gamma Technologies, 601 Oakmont Lane, Suite 220, Westmont, IL 60559, USA.
- Sasayama, T. et al, “A New Electronic Engine Control System Using a Hot-Wire Air Flow Sensor”, SAE 820323, 1982.
- Bosch Automotive Handbook, Fourth Edition, ISBN 1-56091-918-3, 1996, pp. 468-470.
- Ribbens, W.B., “Understanding Automotive Electronics”, Fourth Edition, ISBN 0-672-27358-6J, 1994, pp. 195-198.
- Benson R.S., Garg, R.D., and Woollatt,D., “A Numerical Solution of Unsteady Flow Problems”, Int.J.Mech.Sci., Vol.6, pp. 117-114, 1964..
- Takizawa, M., Uno, T., Oue, T., and Tadoyoshi, Y., “A Study of Gas Exchange Process Simulation of an Automotive Multi-cylinder Internal Combustion Engine”, SAE 820410, 1982.
- Chapman, M., Novak, J.M., and Stein, R.A., “Numerical Modelling of Inlet and Exhaust Flows in Multi-Cylinder Internal Combustion Engines”, Flows in Internal Combustion Engines, UzkanT. (Editor), ASME WAM, 1982.
- Gosman, A.D.,“Multidimensional Modelling of Cold Flows and Turbulence in Reciprocating Engines”, SAE Paper 850344, 1985.
- Garrett T.K., “Automotive Fuels and Fuel Systems, Volume2”, Chapter 11, ISBN 1-56091-510-2, 1994.
- Heisler, H., “Advanced Engine Technology”, Chapter 5, ISBN 1-56091-734-2, 1995.
- Sykes R. “The Tickford variable Geometry Induction System”, Presented at the ImechE Seminar: variable Geometry Engines, S990, 1991.
- Matlab Version 4.2c.1 Software, The Mathworks, Inc., 24 Prime Park Way, Natick, Mass. 01760-1500, USA