Control of vortex shedding behind a circular cylinder using a combination of slot and control plates

Abstract

Present numerical study aims at suppression of vortex shedding formed over a circular cylinder using different combinations of slot and control plates. Unsteady, two–dimensional computations are carried out for laminar, isothermal conditions at a Reynolds number (Re) of 150 using commercially available CFD software ANSYS-Fluent™. Numerical simulations with different passive controlling methods have been carried out to reduce the vortex shedding frequency or to suppress it completely by using the configurations, such as cylinder with control plates, and cylinder with combinations of slots and control plates. By carefully comparing the numerical results of all the cases, it is found that cylinder with control plates at 5° angle is the best case where the vortex shedding is completely suppressed which in turn reduces the drag force significantly. However, in other cases, it was partially suppressed but increases the drag force due to vortex formed near to the control plates or not having any effect on vortex shedding. The results are presented in terms of vorticity and streamline contours, Cl, Cd and Strouhal number.