直肋微小通道流动与换热特性的数值研究

Numerical Study of the Flow and Heat Transfer Characteristics of Straight Rib Microchannels

摘要: 本文针对IGBT模块散热问题设计了直肋微小通道的物理模型，分析了结构参数对直肋微小通道的流动与传热特性的影响。结果表明：适当增加齿高可通过扩展传热面积和增强湍流扰动提升换热效率；然而，当H_c进一步增加使得阻力系数f急剧上升，这是由于凹槽深度过大导致的流体滞留与流动分离现象。同时温度场分析可知，H_c = 1.5 mm时齿峰末端因回流导致局部温度回升，验证了过高齿高对换热的抑制作用。顶端间隙H_a适当扩大改善了流体通过性并削弱了上壁面边界层的影响。齿顶角α通过改变流场扰动强度与流动分离特性影响性能。α增大时，齿形平缓化减少了流动分离，温度场分布均匀性提升。

Abstract: In this paper, a physical model of straight-ribbed microchannel is designed for the heat dissipation of IGBT module. The effects of structural parameters on the flow and heat transfer characteristics of straight-ribbed microchannel are analyzed. The results show that increasing the tooth height can improve the heat transfer efficiency by expanding the heat transfer area and enhancing the turbulence perturbation; however, when H_c is further increased, the drag coefficient f rises sharply, which is due to the phenomenon of fluid stagnation and flow separation caused by the excessive depth of the notch. Meanwhile, the temperature field analysis shows that when H_c = 1.5 mm, the local temperature rises at the end of the tooth peak due to reflux, which verifies the inhibitory effect of too high tooth height on heat transfer. Appropriate expansion of the apical gap H_a improves the fluid passage and weakens the influence of the boundary layer on the upper wall. The tooth apex angle α affects the performance by changing the intensity of the flow field disturbance and the flow separation characteristics. α increases, the flattening of the tooth shape reduces the flow separation, and the uniformity of the temperature field distribution is improved.