DOI: 10.1615/THMT-18
ISBN Print: 978-1-56700-468-7
ISBN Online: 978-1-56700-467-0
ISSN Print: 2377-2816
Heat transfer and flow field measurements of a pulsating round jet impinging on a flat heated surface
SINOPSIS
Previous studies have shown that unsteady, pulsating jets may increase heat transfer in comparison to steady impinging jets having the same average jet exit mass flow rate. In this study, the heat transfer and flow field characteristics of a pulsating, round jet impinging on a flat plate were measured. The surface to jet nozzle stand-off distance equaled two jet diameters and Reynolds numbers based on the average jet exit velocity were Re = 4,604, 8,024 and 13,513. The jet exit velocity varied nearly sinusoidal at pulsating frequencies of 0.67, 1.33, 2.0 and 2.67 Hz. The results were compared to steady jet impingement and showed that at the two lowest Re, the total heat flux increased when the jet was pulsating. Heat transfer improvement of maximum 14% and 4% at Re = 4,604 and 8,024, respectively, were obtained within the studied frequency range.