Flows past a Rotating Circular Cylinder by the VIC Method. Flows at Low Reynolds Numbers and the Reverse Magnus Effect at High Reynolds Numbers.

Two dimensional viscous flows past a rotating circular cylinder are numerically calculated by the Vortex-in-Cell (VIC) method. The Random Walk method is used to simulate the diffusion of the vorticity. At a Reynolds number of 3×105, the reverse Magnus effect, is detected by introducing turbulent viscosity to an area of the deceleration side. The effect of the separation bubble for the reverse Magnus effect is also simulated. At low Reynolds numbers, results obtained by the VIC method agree well with those obtained by experiments and Oseen approximation. The validities of the VIC method and the Random Walk method are proved even in the low Reynolds number range.