Thermal performance of plate-fin heat sinks under confined impinging jet conditions

Abstract

This paper utilizes the infrared thermography technique to investigate the thermal performance of plate-fin heat sinks under confined impinging jet conditions. The parameters in this study include the Reynolds number ( Re), the impingement distance ( Y/ D), the width ( W/ L) and the height ( H/ L) of the fins, which cover the range Re = 5000–25,000, Y/ D = 4–28, W/ L = 0.08125–0.15625 and H/ L = 0.375–0.625. The influences of these parameters on the thermal performance of the plate-fin heat sinks are discussed. The experimental results show that the thermal resistance of the heat sink apparently decreases as the Reynolds number increases; however, the decreasing rate of the thermal resistance declines with the increase of the Reynolds number. An appropriate impingement distance can decrease the thermal resistance effectively, and the optimal impingement distance is increased as the Reynolds number increases. Moreover, the influence of the impingement distance on the thermal resistance at high Reynolds numbers becomes less conspicuous because the magnitude of the thermal resistance decreases with the Reynolds number. An increase of the fin width reduces the thermal resistance initially. Nevertheless, the thermal resistance rises sharply when the fin width is larger than a certain value. Increasing the fin height can increase the heat transfer area which lowers the thermal resistance. Moreover, the influence of the fin height on the thermal resistance seems less obvious than that of the fin width. To sum up all experimental results, Reynolds number Re = 20,000, impingement distant Y/ D = 16, fin width W/ L = 0.1375, and fin height H/ L = 0.625 are the suggested parameters in this study.