Noncommuting Filters and Dynamic Modelling for Les of Turbulent Compressible Flow in 3D Shear Layers
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Large-eddy simulation of complex turbulent flows involves the filtering and modelling of small scale flow structures whose intensity shows large spatial variations in the flow domain. This suggests the use of filters with nonuniform filterwidth. Such filters fail to commute with spatial derivatives and give rise to additional ‘noncommutation’ terms in LES. We construct higher order filters and show that the subgrid terms and the new noncommutation terms are a priori of comparable magnitude. We apply these filters to DNS data of the temporal mixing layer. The magnitude of the noncommutation terms and their contribution to the kinetic energy dynamics is determined. Finally, we show that LES predictions significantly depend on the specific explicit filter used in dynamic subgrid modelling.
KeywordsLarge Eddy Simulation Order Filter Direct Numerical Simulation Data High Order Filter Complex Turbulent Flow
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- B.J. Geurts, A.W. Vreman, J.G.M. Kuerten, ‘Comparison of DNS and LES of transitional and turbulent compressible flow: flat plate and mixing layer’, AGARD Conf. Proc. 551, 5.1–5–14, Chania, Crete, Greece, (1994)Google Scholar
- S. Ghosal, P. Moin, ‘The basic equations for the Large Eddy simulation of turbulent flows in complex geometry’, J. Comp. Phys., 118, 24, (1995)Google Scholar