COMPARISON BETWEEN STANDARD AND DYNAMIC TYPE OF SMAGORINSKY SGS MODEL : Large eddy simulation of turbulent vortex shedding flow past 2D square cylinder using Dynamic SGS model (Part 1)

Abstract

A turbulent vortex-shedding flow past a two-dimensional (2D) square cylinder at Re=2.2×10^4 was simulated by Large Eddy Simulation (LES) using the dynamic Subgrid-scale (SGS) model. Here, the dynamic SGS model was incorporated into the second-order finite volume method. Results from the dynamic SGS model were compared with those from the standard Smagorinsky SGS model and the experiments conducted by Lyn. The dynamic SGS model improved the accuracy of the predictions remarkably. The mean velocity distribution given by the dynamic SGS model showed very close agreement with the experiment in the wake region, while the standard Smagorinsky model somewhat underestimated the size of the reverse flow region behind the cylinder.