ON TURBULENT VORTEX SHEDDING FLOW PAST 2D SQUARE CYLINDER PREDICTED BY CFD

Analyses by CFD on unsteady flow fields past a two-dimensional (2D) square cylinder are reviewed. The accuracy of the predicted results by CFD is examined from various view points. In the first part of the paper, the comparison of the results of large eddy simulation (LES) for 2D and 3D computations are described. The LES results given from 3D computation agree very well with the experimental results, but the results based on 2D computation are different from those based on 3D computation as well as from those given from experiments. The second part of the paper concerns detailed testing of 3D LES computations for the analysis of periodic and stochastic fluctuations, for which detailed experimental data are available. Results of LES computations are compared with those from turbulence models based on Reynolds-averaged Navier-Stokes equations (RANS models) as well as with those from experiments. Finally, results of 3D LES of unsteady pressure field and wind force acting on an oscillating square cylinder are presented.