mpingement cooling of a semi-cylindrical concave channel by confined slot-air-jet

An experimental and numerical study has been carried out for jet impingement cooling of a concave channel when the slot-jet was situated at the symmetry line of a semi-circular channel. In experiments, a parametric investigation is performed to measure the impingement surface pressure distributions and the local Nusselt numbers by varying the jet Reynolds number in the range from 200 to 11 000, and the slot-to-surface spacing from 2.2 to 4.2 of the slot width. For the range of Reynolds numbers studied, the heat transfer rates at the impingement surface of the concave channel are found to be more enhanced than the flat channel results due to the effect of channel curvature. A correlation for the stagnation region heat transfer, which accounts for the channel height effect, is presented. A numerical model, based on the finite-volume procedure, is constructed and validated by comparing the results with the experimental data at low Reynolds numbers. Due to large discrepancy between the experimental and the numerical results at high Reynolds numbers, however, the numerical analysis is carried out for flow Reynolds numbers up to 600.