Guan Xiaonan, Xie Zhihui, Nan Gang, Xi Kun, Lu Zhuoqun, Ge Yanlin
College of Power Engineering, Naval University of Engineering, Wuhan 430033, China.
Institute of Thermal Science and Power Engineering, Wuhan 430205, China.
Micromachines (Basel). 2022 Dec 2;13(12):2136. doi: 10.3390/mi13122136.
A three-dimensional convective heat transfer model of a microchannel pin-fin hybrid heat sink was established. Considering the non-uniform heat generation of 3D stacked chips, the splitting distance of pin-fins was optimized by minimizing the maximum heat sink temperature under different heat fluxes in the hotspot, the Reynolds numbers at the entrance of the microchannel, and the proportions of the pin-fin volume. The average pressure drop and the performance evaluation criteria were considered to be the performance indexes to analyze the influence of each parameter on the flow performance and comprehensive performance, respectively. The results showed that the maximum temperature of the hybrid heat sink attained a minimum value with an increase in the splitting distance. The average pressure drop in the center passage of the microchannel first increased and then decreased. Furthermore, the optimal value could not be simultaneously obtained with the maximum temperature. Therefore, it should be comprehensively considered in the optimization design. The heat flux in the hotspot was positively correlated with the maximum heat sink temperature. However, it had no effect on the flow pressure drop. When the Reynolds number and the pin-fin diameter increased, the maximum heat sink temperature decreased and the average pressure drop of the microchannel increased. The comprehensive performance of the hybrid heat sink was not good at small Reynolds numbers, but it significantly improved as the Reynolds number gradually increased. Choosing a bigger pin-fin diameter and the corresponding optimal value of the splitting distance in a given Reynolds number would further improve the comprehensive performance of a hybrid heat sink.
建立了微通道针翅混合散热器的三维对流换热模型。考虑到三维堆叠芯片发热不均匀的情况，通过在热点区域不同热流密度、微通道入口处雷诺数以及针翅体积占比等条件下，使散热器最高温度最小化，对针翅的分割间距进行了优化。分别将平均压降和性能评价准则作为性能指标，来分析各参数对流动性能和综合性能的影响。结果表明，混合散热器的最高温度随着分割间距的增加而达到最小值。微通道中心通道的平均压降先增大后减小。此外，无法同时获得与最高温度对应的最优值。因此，在优化设计中应综合考虑。热点区域的热流密度与散热器最高温度呈正相关。然而，它对流动压降没有影响。当雷诺数和针翅直径增大时，散热器最高温度降低，微通道的平均压降增大。混合散热器在小雷诺数时综合性能不佳，但随着雷诺数逐渐增大，其综合性能显著提高。在给定雷诺数下选择更大的针翅直径和相应的最优分割间距值，将进一步提高混合散热器的综合性能。
