双层壁冷却结构中多排射流冲击冷却的换热和流阻特性

Heat transfer and flow resistance characteristics of multi-row jet impingement cooling in double-wall cooling structure

采用稳态热敏液晶技术对双层壁冷却结构中的多排(包括顺排和叉排)射流冲击冷却结构进行了风洞实验,同时结合数值模拟的方法,对两种射流冲击冷却结构的传热和流阻特性的差异进行了研究。实验结果表明:流量系数和冲击靶板上的努塞尔数均随着雷诺数的增大而增大,而冲击孔的排布方式对面平均努塞尔数的影响较小,但是叉排结构的流量系数高于顺排结构,且冲击靶板上换热更加均匀。数值结果显示冲击靶板中心区域的流量分配和换热均随着冲击距离的增大而增大;而在下游区域内恰好与之相反。

The heat transfer and flow resistance characteristics of the jet impingement cooling in double-wall cooling structure were experimentally and numerically studied. The cooling structure with inline and staggered patterns were experimentally studied in the wind tunnel with steady-state thermo-chromic liquid crystal technology, and the differences of heat transfer and flow resistance characteristics of two structures were studied. The experimental results indicated that both the discharge coefficient and Nusselt number on the target plate increased with the increase of Reynolds number,and the influence of impingement hole arrangement on the averaged Nusselt number was small. However,the discharge coefficient of the staggered cooling structure was higher than that of the inline pattern,and the heat transfer on the target plate was more uniform. Furthermore, the numerical results showed that distribution of the mass flow rate and the heat transfer in the central region of target plate increased with the increase of impact distance,while the opposite phenomenon occurred in the downstream area.