Feedback control of vortex shedding around a bluff body by velocity excitation

A feedback control technique of vortex shedding behind a circular cylinder is investigated by means of two-dimensional numerical simulations. Fluid velocity excitation is applied to the separated shear flows at two positions on the cylinder surface with time delay and feedback gain for the fluid velocity at a downstream sensor position. It is shown that the feedback excitation can suppress the vortex shedding considerably, if the time delay of the excitation is varied in accordance with the change of the vortex shedding period and the sensor is located inside the vortex formation region behind the cylinder.