Effect of splitter plate angular position on wake characteristics of a cylinder

This study experimentally investigates the wake characteristics dynamics of a circular cylinder at Re = 7500 with uniform flow in a recirculating water channel, utilizing the particle image velocimetry (PIV) technique. The research examines the passive control of unsteady vortex shedding downstream of a cylinder using a splitter plate placed parallel to the cylinder surface, focusing on the effects of the oncoming flow angle and plate length. The experimental results are presented in terms of vorticity and Reynolds shear stress contours, as well as variations of maximum turbulent kinetic energy and Strouhal number with respect to the flow angle, to provide insight into the underlying fluid dynamics and vortex formation mechanisms. The gap ratio between the cylinder surface and the plate was kept constant at g/D= 0.9 for all cases. The oncoming flow angles were set to α= 130°, 140°, 150°, and 180°, while the plate length ratios were assigned as L/D= 0.5 and 1. The position and length of the splitter plate directly affect the vortex structures compared to the base cylinder case. The most effective oncoming flow angle varies with the plate length. Overall, the results indicate that splitter plates provide an effective means of flow control by suppressing vortex formation across all flow angles.