Effect of Corner Curvature of Square Cylinder on Flow Transition and Heat Transfer

Fluid flow and heat transfer over a square cylinder with modified corners are studied numerically at a very low Reynolds number (Re). The present study aims to investigate the flow transition from a creep flow to a steady separated flow and the corresponding effect on the heat transfer characteristic. The corners of the square cylinder are modified by changing the corner curvature and are varied from 0 to 1. The effect of corner curvature radius on the critical Reynolds number (Recr) where the flow transition occurs is investigated along with the flow features, and heat transfer characteristics at the Recr. It is found that Recr increases approximately exponentially with the increasing of corner curvature radius and the Recr is found always less than 7 for all the considered cases. In addition, the drag coefficient decreases with the increment of corner curvature radius. Corner curvature radius (CCR) also influences the Nusselt number (Nu). It is perceived that the Nu increases with increase in corner curvature radius (CCR) and as well as with increasing Re.