阵列射流-扰流柱复合冷却结构换热和压降特性数值研究

为研究阵列射流-扰流柱耦合换热结构对热端部件综合冷却效果的影响,采用数值模拟方法研究了阵列射流-扰流柱复合冷却结构的流动换热特性,重点关注扰流柱相对于射流孔的布置方式(顺排和叉排)、扰流柱直径d_p相对于射流孔的直径d_j之比(d_p/d_j=0.5,1,2)的影响。为体现阵列射流-扰流柱复合冷却结构的导热-对流强耦合传热过程特征,引入了靶板加热侧当量对流换热系数的概念,并分别采用冲击靶面对流换热系数和靶板加热侧当量对流换热系数进行了综合性能的评价分析。研究结果表明,采用绕流柱顺排和叉排方式的冲击靶面对流换热相较于光滑靶板分别增加约30%和10%,而扰流柱相对于射流孔呈顺排方式的对流换热效果要优于叉排方式,同时,顺排方式的压力损失系数却低于叉排方式。至于扰流柱相对于射流孔的直径比的影响,基于冲击靶面和靶板加热侧对流换热系数的综合性能评价存在显著的差异。

Numerical Study on Heat Transfer and Pressure Drop of an Integrated Array-Jets and Pin-Fins Cooling Configuration

A numerical study was performed to investigate the flow and heat transfer characteristics of an integrated array-jets and pin-fins cooling structure, with the main concern on the effects of pin-fins arrangement with respect to the impinging holes (inline and staggered modes) and fin-to-hole diameter ratio (dp/dj=0.5, 1 and 2). In order to consider the highly-coupling feature of heat conduction and heat convection in the integrated cooling structure, an equivalent convective heat transfer coefficient on the heated side of target plate was introduced. By using the convective heat transfer coefficient on targeting surface and the equivalent convective heat transfer coefficient on heated side of target plate, an evaluation on the comprehensive performance of integrated cooling structure was made. The results show that the inline mode of pin fins is more pronounced on enhancing the convective heat transfer when compared to the staggered mode. Simultaneously, the pressure loss in the inline mode is otherwise less than the staggered mode. With regard to the effect of fin-to-hole diameter ratio, it is found that the comprehensive performance evaluation based on the equivalent convective heat transfer coefficient on heated side of target plate is significantly different from that based on the convective heat transfer coefficient on targeting surface.