Large Eddy Simulation of Turbulent Flows in a Laboratory Reciprocating Engine
Large eddy simulation (LES) of turbulent flows in an experimental reciprocating internal combustion engine was carried out. The engine had a rectangular shaped combustor geometry and rectangular channel intake and exhaust manifolds with a large optical window to allow for detailed two-dimensional velocity field measurement in the entire combustion chamber. The objectives of this work were to study the structures of the tumble flow and turbulence in the combustion chamber and to examine different approaches for characterizing the incylinder turbulent flows. LES were performed for two different engine configurations, one with the intake channel included in the simulation and one with intake flow modeled as a simple plug flow at the exit of the intake channel, to investigate the effect of intake flow on the tumble flow and turbulence. The convergence of cycle-averaged statistics was investigated. It was found that for the ensemble averaged mean flow field 10 cycles LES could give reasonably converged mean velocity; however, more than 60 cycles were needed to generate converged rms of velocity fluctuation. A global turbulence intensity defined based on single cycle LES or PIV data was analyzed. This quantity was shown to characterize the overall turbulence intensity in the cylinder reasonably well.
KeywordsLarge Eddy Simulation Large Eddy Simulation Result Crank Angle Degree Intake Stroke Intake Flow
Unable to display preview. Download preview PDF.
- 3.Yu, R., Bai, X., Vressner, A., Hultqvist, A., Johansson, B., Olofsson, J., Seyfried, H., Sjoholm, J., Richter, M., Alden, M.: Effect of Turbulence on HCCI Combustion. SAE paper 2007-01-0183 (2007)Google Scholar
- 4.Joelsson, T., Yu, R., Bai, X., Vressner, A., Johansson, B.: Large Eddy Simulation and Experiments of the Auto-Ignition Process of Lean Ethanol/Air Mixture in HCCI Engines. SAE paper 2008-01-1668 (2008)Google Scholar
- 9.Joelsson, T., Yu, R., Bai, X.S., Takada, N., Sakata, I., Yanagihara, H., Lindén, J., Richter, M., Aldén, M., Johansson, B.: Flow and Temperature Distribution in an Experimental Engine: LES Studies and Thermographic Imaging. SAE paper 2010-01-2237 (2010)Google Scholar
- 12.Yu, R., Bai, X.S.: A semi-implicit scheme for large Eddy simulation of piston engine flow and combustion. Int. J. Numer. Meth. Fluids (2012), doi:10.1002/fld.3644Google Scholar
- 14.Reynolds, W.C.: Modeling of fluid motions in engines – an introductory overview. In: Mattavi, J.N., Amann, C.A. (eds.) Combustion Modeling in Reciprocating Engines, pp. 69–124. Plenum Press (1980)Google Scholar
- 15.Heywood, J.B.: Internal combustion fundamentals. McGraw Hill Int. Editions. McGraw-Hill, Inc. (1988)Google Scholar
- 16.Le Coz, J.F., Henriot, S., Pinchon, P.: An experimental and computational analysis of the flow field in a four-valve spark engine – focus on cycle-resolved turbulence. SAE paper 900056 (1990)Google Scholar
- 17.Li, Y., Liu, S., Shi, S.-X., Feng, M., Sui, X.: An investigation of in-cylinder tumble motion in a four stroke spark ignition engine. Proc. Instn. Mech. Engrs. 215(part D), 273–284 (2001)Google Scholar