Large eddy simulation using a curvilinear coordinate system for the flow around a square cylinder

Abstract

The application of Large Eddy Simulation (LES) in a curvilinear coordinate system to thernflow around a square cylinder is presented. In order to obtain sufficient resolution near the side of therncylinder, we use an O-type grid. Even with a curvilinear coordinate system, it is difficult to avoid thernnumerical oscillation arising in high-Reynolds-number flows past a bluff body, without using an extremelyrnfine grid used. An upwind scheme has the effect of removing the numerical oscillations, but, it isrnaccompanied by numerical dissipation that is a kind of an additional sub-grid scale effect. Firstly, werninvestigate the effect of numerical dissipation on the computational results in a case where turbulentrndissipation is removed in order to clarify the differences between the effect of numerical dissipation. Next,rnthe applicability and the limitations of the present method, which combine the dynamic SGS model withrnacceptable numerical dissipation, are discussed.