NUMERICAL ANALYSIS OF LOCAL HEAT TRANSFER FROM A FLAT PLATE TO A SWIRLING AIR IMPINGING JET

摘要

Local heat transfer from a flat plate to a swirling circular air impinging jet is investigated numerically. Reynolds Averaged Navier-Stokes equations (RANS) and energy equation are solved for the axisymmetric, three dimensional flow. Eddy-viscosity based turbulence models, RNG and V2F, are used. Non-uniform meshes are used for the three dimensional flows and mesh independent solutions are obtained. The flow Reynolds number, which is based on the jet diameter, is kept at 23,000. In the analysis, local heat transfer coefficients are obtained for different swirl numbers, S = 0.21, 0.35 and 0.47 and jet-to-plate distance, L/D, ranging from 2 to 9. Investigation of the effect of swirl flow profile at the exiting plane of the jet on heat transfer is also presented. It is found that different swirl profiles with the same swirl number lead to very different heat transfer behaviors in the stagnation region of the impinging jet.