Abstract
The present study is designed to experimentally investigate the flow field past a rotary oscillating circular-cylinder in a uniform stream. Experiments were conducted with Re_d = 800 at the rotational speed ratio of 2 and the frequency normalized by a natural vortex shedding frequency in the range of 0.7 to 2.5. Instantaneous velocity fields were acquired with a particle image velocimetiy (PIV), and analyzed using an ensemble-averaging technique. The intensity of vortices discharged into the wakes and the spatiotemporal spacing of the vortex street were examined.
