Experimental analysis of the thermal performance on electronic cooling by a combination of cross-flow and an impinging air jet

摘要

This paper reports the experimental results of the thermal analysis of an electronic component placed in a rectangular channel cooled by the combination of a cross flow and an impinging jet. An infrared thermography technique was used to determine the surface temperature distributions and so calculate the heat transfer coefficient, heat flux rate and Nusselt number. From these results, the effects of the main flow structures were related with the local heat transfer processes according to different correlations determined. The influence of two parameters, namely, the channel Reynolds number and the jet-to-channel Reynolds number ratio (alpha), on the heat transfer was studied considering three values of the channel Reynolds number (3410, 5752 and 8880) and three values of the ratio alpha (0.5, 1.0 and 1.5). Moreover, the head losses around the component were obtained and analysed jointly with the heat transfer, and the performance of the studied flow configuration was determined and compared with the case of the channel flow without impinging jet. The results show that the ratios alpha of 1.0 and 1.5 produce the impact of the jet on the top face of the component causing a large removal of the heat flux. When low values of the power head losses were used, the performance of the cooling process for the flow configuration (cross flow and impinging jet) was higher than in case of a channel without impinging jet.