On the wake of a cylinder with rotational oscillations

The unsteady viscous flow over a rotationally oscillating cylinder in a uniform flow has been numerically and experimentally investigated. Solution of the full Navier-Stokes equations in the form of vorticity and stream functions shows that the forces acting on the cylinder depend on the oscillation frequency and amplitude. Flow visualization results indicate that when the forcing frequency is near the natural vortex shedding frequency, the shed vortex in the wake becomes more organized.