Turbulent heat transfer enhancement in the mini-channel by enhancing the original flow pattern with v-ribs

摘要

Turbulent heat transfer attracts continuous attention from researchers due to the high convective heat transfer performance. In the mini-channel heat sink, turbulent heat transfer enhancement measures may improve the heat transfer coefficient further and reduce the mass flow rate. However, there is lack of turbulent heat transfer enhancement researches in the mini-channel heat sink due to the difficulty caused by entrance effect. In this paper, a novel heat transfer enhancement concept of enhancing the original flow pattern was successfully applied to enhance the turbulent heat transfer in the mini-channel heat sink. The investigation was carried out in a mini-channel heat sink whose substrate size was 50mm x 50mm with Reynolds number ranging from 3600 to 6800. The original flow pattern in the conventional heat sink was revealed firstly. Subsequently, the v-ribs roughness was applied to generate multi-longitudinal swirls flow so as to enhance the original flow pattern. The numerical results indicated that the variation ranges of Nu/Nu_0, f/f_0. EEC, and R3 were 1.71-3.55, 2.76-7.99, 0.32-0.89, and 1.12-2.06, respectively, in the mini-channel. Besides, the maximum average heat flux of the substrate could achieve 5.79 W/mm~2 within a temperature difference of 60 K. In addition, this paper also investigated the thermal resistance and irreversibility in the mini-channel heat sink. This work may promote the development of heat transfer enhancement.