Flow Structures around a Square Cylinder: Effect of Corner Chamfering

In this paper, results of a flow visualization study on the flow around a square cylinder with corner chamfering are presented. The corners of the test cylinders were chamfered with each corner forming a triangle with chamfer dimension b. Experiments were conducted for b/Bo ratios of 0.05, 0.1, 0.2, and 0.3 where Bo is the side dimension of the uncut square cylinder. The flow structures, particularly the vortex shedding mode and mechanism around the uncut as well as chamfered square cylinders, were investigated in order to deduce the effect of corner modification. All the studies were conducted at a Reynolds number value of 2,100 (based on Bo) on both stationary and oscillating cylinders. For oscillating cases, a special mechanism was built to oscillate the cylinders (forced oscillation) at desired amplitudes and frequencies. Results indicates that corner chamfering brings notable changes in the near-wake flow structures of a square section cylinder both in stationary and oscillating conditions. In view of aerospace structures with similar geometries, the present results carry considerable practical significance.