In order to investigate the flow characteristics around a rotating circular cylinder in an uniform shear flow, the experimental study was carried out in a specially designed circulating water channel. The aim was to observe the variation of Strouhal number(St) and the velocity distributions in wake region over a broad range of the shear parameter K (0 ≤ K ≤ 0.15) and the rotation parameter α (-2.0 ≤ α ≤ 2.0). The Reynolds number(Re) of the present experiment was 900. It is found that St increases as K increases ; also St increases as α increases. The Karman vortex street disappears more rapidly in uniform-shear flow than in uniform flow for the same rotation parameter. The negative rotation, which is the same direction of the vorticity of shear flow, represents the significant deterioration of the Karman vortex street rather than the positive rotation with the same speed. Comparing with uniform flow, the velocity defect in uniform-shear flow decreases apparantly as the Karman vortex street disappears, and it vanishes at high rotating speed.
