Numerical Study of Flow Characteristics Around Square Cylinder at High Reynolds Number

Three-dimensional large eddy simulations (LES) were performed at high Reynolds numbers (Re=22 000) and using the dynamic Smagorinsky sub-grid model to investigate uniform flow over a square cylinder. Meshing of the model was performed using Open Foam-an open-source computational tool. Mean integral quantities were compared against existing experimental and numerical results to validate the proposed numerical method. Subsequently, the flow structure around and aerodynamic forces acting on the cylinder were analysed to perform an in-depth investigation of mean-and turbulent-flow characteristics. Lastly, the influence of the grid system around the cylinder and span-wise length on the flow structure and spatial correlation were investigated via comparison between different cases. Results demonstrate that the recirculation length in the wake approximately measured 1.37D (width of square), while the Strouhal number and RMS value of the lift coefficient are 0.121 and 1.40, respectively. In addition, domain length along the span-wise should be equal to 8D in order to obtain clear turbulent-flow characteristics.