Investigation of Flow Fields Around Rectangular Cylinder Under Turbulent Flow by Les

Abstract In the atmospheric boundary layer turbulent flow is continuously interacting with structures. Recently it has been found that properties of natural wind turbulence are anisotropic in nature in terms of turbulence intensity and length scale. It is important to know the bluff body response under this anisotropic turbulent flow. In the present work, anisotropic turbulence effect was investigated numerically on rectangular cylinders of varying side ratios (R=d/h), R=0.1875 to 1. Four different properties of anisotropy were considered and anisotropy of the turbulence was altered by changing the vertical wind turbulence intensity and length scale. Numerical simulations were performed employing large eddy simulation (LES) with smagornisky subgrid-scale model. Turbulence effects were discussed in terms of mean drag and base pressure coefficients. Time averaged flow pattern was plotted to understand the flow field around the rectangular cylinders. After body vortex strength was also checked for turbulent flow. It was found that the anisotropy of turbulence alters bluff body responses considerably.