Heat transfer and air temperature measurements of an impinging synthetic air jet

Abstract

Synthetic jets are a relatively new technology that can achieve high rates of heat transfer. They have been shown to out-perform comparable steady impinging jets without the need for an external air supply system. The current experimental research is concerned with the mean and fluctuating heat transfer and local air temperature distribution of an impinging synthetic jet. Tests were conducted for Reynolds numbers from 1000 to 3000, and nozzle to impingement surface spacings of 2 and 6 diameters. The stroke length was maintained constant and equal to 8 diameters in all the reported data. The results obtained show a strong correspondence between the local heat transfer and air temperatures. The periodicity of the synthetic air jet flow characterise the surface heat flux and local fluid temperature behaviour in the stagnation region. At larger radial distances and Reynolds numbers the influence is less significant however.