Heat transfer enhancement of impinging jets using mesh screens

Abstract

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 ( σ 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⩽4, the turbulence intensity was increased with mesh solidity, causing an increase in the local heat transfer rate. For the screen of σ 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.