Simulation of Turbulent Flow Around a Surface-Mounted Finite Square Cylinder

Numerical investigation of turbulent flow around a surface-mounted square cylinder of aspect ratio h/d = 4 is presented in this paper. The aims are to get detailed information about the flow structures around such a cylinder and to establish a suitable turbulent model that could yield accurate and reliable results for practical industrial applications. Calculations were performed at Reynolds number of 13041 using a Reynolds stress model. The present simulation has successfully reproduced the primary flow, as well as the three-dimensional large-scale vortex structure in the wake of this finite wall-mounted body. The existence of a spanwise vortex, tip vortex, and horseshoe vortex is consistent with previous experimental studies. The half-loop shed structure observed in the previous experimental study has been clearly captured in the isosurface of the instantaneous second invariant of the velocity gradient. Furthermore, the evolution of the vertical vorticity fields in the wake is presented with details at middle span (z/d = 2.0), and the Strouhal number estimated from flow visualization is 0.1, which not only equals to the value obtained by statistical analysis of the streamwise drag coefficient, but also perfectly matches with the value obtained by the previous experimental study carried out under a similar flow condition with the same geometry.