Vortex shedding from a circular cylinder near a moving wall

Flow over a circular cylinder near a moving plane wall is simulated numerically. The influence of the moving wall on the vortex shedding from the cylinder is demonstrated and the corresponding mechanism is illustrated using instability theory. A critical gap ratio between the circular cylinder and the moving wall is defined, and a precise method for determining the critical gap ratio is proposed. The drag and lift forces and the pressure coefficient are presented as a function of the gap ratio. The scaling of the Strouhal number is discussed.