Experimental Investigation of Heat Transfer from a Discretely Heated Protruding Pedestal to a Single Round Impinging Air Jet

摘要

An experimental investigation to understand the influence of the impingement surface geometry on the heat transfer from a discretely heated surface to a single round impinging jet is conducted. In this study, heat transfer at the stagnation region of a discretely heated pedestal protruding into an air stream is compared to the heat transfer on a discretely heated flat plate to determine the influence of impingement surface geometry on heat transfer for various Reynolds numbers, jet diameters and jet exit-surface spacings. The round jet issues from a tube of diameter 3.5 mm, 9.5 mm or 21 mm at jet exit-to-surface distances of 2-5 diameters with Re = 10,000 - 30,000. Under all operating conditions, the presence of a protruding pedestal is found to increase heat transfer.