Investigation on the thermal and hydraulic characteristics of the micro heat sinks with grooves and pin fins by Taguchi-based sensitivity analysis

Abstract

The heat dissipation issue of the micro electronic devices seriously restricts their application in the aerospace, national defense, communication, etc. The novel heat sinks with trapezoidal grooves and rectangular pin fins are proposed to meet the cooling requirement of the high-power devices. The cooling effect, thermohydraulic characteristics, total efficiency and thermodynamic performance of the heat sinks are studied by three-dimensional numerical simulation. Firstly, the influence of the relative position between the grooves and the pin fins on the thermohydraulic performance is explored in detail. Secondly, Taguchi optimization and analysis of variance are adopted to quantitatively analyze the impact degree of the pin fin width, length and height on the Nusselt number, friction factor and total performance index. The optimal structures are obtained for different objectives. Lastly, the temperature performance, total performance and the irreversibility of the optimal structures are compared thoroughly. New findings include that: the best arrangement of the grooves and pin fins is obtained, which enhances the Nusselt number by 1.5 times compared to the smooth heat sink. The fin width is the most critical factor for the heat transfer and flow, while the fin length shows the greatest importance in the overall performance. The optimized heat sink with the fin width of 50 μm, length of 60 μm and height of 150 μm reduces the peak temperature by 12.3 ℃ compared to the smooth heat sink for Reynolds number of 303. This heat sink yields the highest total performance index with 1.43 for Reynolds number of 368 and significantly reduces the irreversible loss. Moreover, the optimized heat sink with the fin width of 10 μm, length of 60 μm and height of 100 μm reduces the friction factor by 61.39 % compared to the original structure for Reynolds number of 635, which is beneficial to reduce the energy consumption. The quantitative analysis of the parameter sensitivity for novel heat sinks reveals the mechanism of the heat transfer enhancement by modifying the geometric parameters and provides an effective solution for thermal management of the high-power devices.