Self-sustained oscillations in the flow past a circular cylinder with splitter plate

Abstract

The problem of generation of self-sustained oscillations in the flow past a circular cylinder with a splitter plate is solved numerically. We investigate both the transient process and the steady periodic vortex shedding behind the cylinder. The evolution of the vorticity field is shown for various length of the splitter plate. It is demonstrated that the splitter oriented along the flow direction significantly reduces the forces applied to the cylinder. With increasing splitter length the average drag decreases monotonically but the amplitudes of oscillation of the forces applied to the body change nonmonotonically. In this paper we offer our explanation of this phenomenon. It is shown that when turning the splitter plate at some angle from the flow direction the process of vortex formation and shedding behind the cylinder is no longer strictly regular and periodic.