NUMERICAL INVESTIGATION OF FLOW AND HEAT TRANSFER CHARACTERISTICS FROM AN IMPINGING JET ON A CIRCULAR CYLINDER

摘要

A study has been made of the flow and heat transfer to a circular cylinder from an isothermal impinging air jet. Numerical solutions of the governing conservation equations have been obtained utilizing a non-orthogonal curvilinear coordinate grid. The study focused on low Reynolds numbers (based on nozzle average exit velocity and cylinder diameter) in the range of 132-1315 and H/W = 2, 4, 6 and 8 which corresponds to the ratio of distance between the nozzle and cylinder to nozzle width. The flow is stable and symmetric over the range of parameters studied. The effects of buoyancy, diffusion and cooling of the cylinder, the development of the wall jet, and the recirculating bubble all affect the flow and heat transfer. The average Nusselt number increases with increasing Reynolds. Also the distance between the nozzle and the cylinder has a strong effect on the heat transfer.