Tailoring the fluid flow distribution in a parallel mini-channel heat sink under multiple-peak heat flux

Abstract

Parallel micro/mini-channel heat sinks are widely used for the efficient cooling of electronic devices to avoid functional damage and lifetime shortening due to overheating. This study addresses the optimization of fluid flow distribution in parallel mini-channel heat sinks subjected to a non-uniform multiple-peak heat flux to eliminate the temperature hotspots. A 3D heat sink comprising of 16 parallel straight mini-channels is used as a model for study, each mini-channel having the dimension of 1 mm in width, 2 mm in height and 34 mm in length. In particular, an original optimization algorithm is developed to adjust the inlets of these mini-channels according to the temperature distribution on the heating base surface. The fluid flow distribution is thereby tailored, leading to the reduced peak temperature on the heating surface. The effectiveness and robustness of the optimization algorithm are tested and discussed.Results obtained show that the maximum temperature can be reduced by 10 K and 7 K for two-peak and five-peak heat flux cases, respectively, by using the proposed optimization method. The heat sink configuration with optimized channel inlets could always provide smaller thermal resistance than that of the equal channel inlet configuration under different average heat flux or total mass flow-rate conditions. At the same pressure drop, tailoring the flow distribution of the cooling fluid is more effective in reducing the thermal resistance than simply increasing the mass flow rate of the cooling liquid. This optimization method could also be generalized as an efficient thermal management technology for electronic cooling.