Active Wake Control of a Bluff Body Using Incompressible Numerical Simulations

The effect of active flow control using suction and blowing on the wake of a bluff body with a blunt trailing edge in a rectangular channel is investigated using URANS simulations and Dynamic Mode Decomposition (DMD). A recirculation loop is added at the rear end of the bluff body to introduce the secondary flow. Vorticity contours are plotted for different secondary flow velocities, and it is observed that the secondary flow can reduce the magnitude of vorticity in the wake of the bluff body by altering the vortex shedding and pressure distribution. The optimal secondary flow velocity is found to be 2.05 m/s. DMD is applied to analyze the flow without control and reveals two dominant modes at frequencies 29.7 and 59.48 Hz, corresponding to the horizontal and vertical motion of the vortical structures in the wake. The results demonstrate the potential of secondary flow injection as a passive control technique for wake reduction.