Numerical Study of Fluid Dynamics and Heat Transfer Characteristics for the Flow Past a Heated Square Cylinder

Effects of inertia and buoyancy forces are numerically investigated on fluid dynamics and heat transfer characteristics for the flow past a heated square cylinder in an unconfined flow regime. Non-dimensional number in the study chosen are Re = 1 - 45, Ri = 0 - 1.50, alpha = 0o- 90o. The orientation of the cylinder and the Prandtl number are kept fixed as phi = 0oand Pr = 100. Numerical experiments in generalized body-fitted coordinates subject to Boussinesq approximation were conducted in the form of solution of continuity, momentum and energy equations. The momentum and energy equations are discretized using finite difference method. The equations are solved by using SMAC type implicit pressure correction scheme. The flow is noticed steady for 1 <= Re <= 30 and 0 <= Ri <= 0.50 at alpha = 0o, 1 <= Re <= 20 and 0 <= Ri <= 0.50at alpha = 45o, 1 <= Re <= 10 and 1.0 <= Ri <= 1.50 at a = 90o. Onset of vortex-shedding is observed initially at Re = 30, alpha = 45o, 0 <= Ri <= 0.50, the flow becomes unsteady and periodic flow. At small magnitudes of Reynolds number, the wake on downstream side of cylinder is found thin, and it becomes wider at large magnitudes of Reynolds number. It is noticed that the width of the wake reduces in size with increasing Richardson number. Maximum mean lift coefficient is found to occur at Re = 20, Ri = 1.5 and alpha = 90o, and maximum mean drag coefficient is noted at Re = 1 for the chosen range of Richardson number and free-stream orientations. For the whole range of Reynolds and Richardson numbers, the front face(s) of the cylinder had more crowding of isotherms in comparison with other faces of the cylinder. The front face(s) of the cylinder have high rate of heat transfer as compared to other cylinder faces. Heat transfer rate from the cylinder is enhanced either with increase in Richardson number or Reynolds number. (C) 2021 Jordan Journal of Mechanical and Industrial Engineering. All rights reserved