Heat transfer enhancement of impinging jets using mesh screens

The heat transfer characteristics of a sharp-edged orifice jet impinging on a flat plate were investigated experimentally with varying the solidity of the mesh screen (sigma(s)) installed in front of the jet nozzle. The screen modified the flow structure of the free jet, leading to a change in the local heat transfer characteristics. For nozzle-to-plate spacings of z/d less than or equal to 4, the turbulence intensity was increased with mesh solidity, causing an increase in the local heat transfer rate. For the screen of sigma(s) = 0.83, the local maximum heat transfer rate was increased about 3.92% at z/d = 4 and the average Nusselt numbers was enhanced about 1.38% at z/d = 2, compared with those for the case of no screen. (C) 2004 Elsevier Ltd. All rights reserved.