Abstract:

Based on the field synergy principle, a pin-fin multi inclined jet microchannel heat sink for efficient cooling of electronic components was proposed. The impacts of inclined jet angle (θ), relative pin fin height (α), and crossflow on the flow and heat transfer characteristics of the heat sink are investigated through numerical simulations. The results showed that, pumping power firstly decreased and then increased with the increase of jet angle, and thermal resistance monotonically decreased with the increase of jet angle and reached the minimum value at θ=150°. The pin fin can destroy the helical flow caused by the jet and strengthen the heat transfer in the crossflow region, and the combination of the pin fin and the inclined jet can achieve better heat transfer performance. To comprehensively study the overall performance of the pin-fin inclined jet impingement microchannel, radial basis function neural networks and the NSGA-Ⅱ genetic algorithm were employed for multi-objective optimization of thermal resistance and pumping power. Under the same pumping power, the optimized thermal resistance decreases by 26.0% compared to that of the smooth multi vertical jet microchannel, while under the same thermal resistance, the optimized pumping power decreases by 94.6%. Furthermore, the thermal resistance and pump power of the optimal compromise solution selected by TOPSIS combined with the entropy weighting method are 0.055 K/W and 0.56W, respectively.

Key words: microchannel, inclined jet, pin fin, heat transfer enhancement, optimization

摘要：

基于场协同理论，提出了一种针翅式多孔倾斜射流微通道热沉用于电子元件的高效冷却。通过数值模拟研究了倾斜射流角度（θ）、翅片相对高度比（α）和通道横流对微通道内流动与传热特性的影响。研究发现：泵功随着射流角度的增加先减小后增大，热阻随着射流角度的增加单调减小，当射流角度θ=150°时热阻最小；针翅片具有破坏射流引起的螺旋流并强化横流区传热的作用，且针翅片与倾斜射流的组合能实现更好的传热性能。最后，为了获得综合性能更优的微通道参数，采用径向基神经网络与NSGA-Ⅱ遗传算法对热阻和泵功进行了多目标优化。与同水力直径下射流雷诺数（Re_j）为1000的光滑垂直多孔射流微通道相比，在相同泵功下优化后的热阻下降了26.0%；在相同热阻下，优化后的泵功下降了94.6%。通过结合熵权法TOPSIS选取的热阻与泵功最优折衷解分别为0.55K/W和0.56W。

关键词: 微通道, 倾斜射流, 针翅片, 强化换热, 优化