NON-NEWTONIAN FLOW AND HEAT TRANSFER OVER AN INCLINED SQUARE CYLINDER CONFINED IN A CHANNEL

Abstract

In this study, flow and heat transfer around an inclined square cylinder confined in a horizontal plane channel to power-law fluids has been investigated for the range of conditions: Reynolds number, Re = 1 - 40, power-law index, n = 0.4 — 1 (covering shear-thinning and Newtonian behaviours), blockage ratio = 12.5% — 50% and Prandtl number, Pr =50. The governing cauchy's equations along with boundary conditions are solved by using a commercial CFD solver Ansys Fluent. The grid is generated by using Gambit. Extensive numerical results are presented on the local and global characteristics' of fluid flow like as: flow patterns, wake/recirculation length, individual and overall drag coefficients, variation of pressure coefficient and heat transfer characteristics as isotherm patterns, average Nusselt number, and Strouhal number are reported to elucidate the combined effect of power-law index, blockage ratio and Reynolds number. The size of vortices decreases with an increase in the value of the blockage ratio and/or power-law index. The wake length of Newtonian fluid (n = 1) is found to be less than shear-thinning fluid (n < 1) for the values of the blockage ratio of 25% and 50%. For a fixed'value of the Reynolds number, individual and overall drags decrease with decrease in power-law index and/or blockage ratio in steady confined flow regime