Enhancement of air jet impingement heat transfer using pin-fin heat sinks

The enhancement of heat transfer from a discrete heat source in confined air jet impingement was experimentally investigated, A variety of pin-fin heat sinks were mounted on the heat source and the resulting enhancement studied. Average heat transfer coefficients are presented for a range of jet Reynolds numbers (8000 less than or equal to Re less than or equal to 45000) and orifice diameters (12.7 less than or equal to d less than or equal to 38.1 mm). A total fin effectiveness was computed for the pinned heat sinks relative to the unpinned ones, and was in the range of 2.4 to 9.2; the highest value was obtained for the largest nozzle diameter. Heat transfer rates from the bare heat source were increased by a factor of 7.5 to 72 due to the introduction of the heat sinks. Results for the average heat transfer coefficient were correlated in terms of Reynolds number, fluid properties and geometric parameters of the heat sinks.