Numerical study of a linear shear flow past a rotating cylinder

The effects of shear rate on flow past a rotating circular cylinder in a linear shear flow have been investigated by using a hybrid vortex method at a Reynolds number of 1000. The velocity gradient of the shear flow K ranges from -0.3 to 0.3 and the rotational to translational speed ratio or is 0.5. The results show that the form of vortex shedding is controlled by the shear parameter K. The drag coefficient decreases with increasing \K\. On the other hand, the lift coefficient and Strouhal number increase as K increases. As K increases, the separation positions shift downstream, the wake becomes narrower and the amplitude of fluctuation of the instantaneous lift and drag coefficients decreases.