具有气膜出流孔和针肋的双层壁冷却结构内的冲击传热性能

针对具有气膜出流孔和针肋的双层壁冷却结构内冲击传热性能进行了试验和数值计算研究。试验采用瞬态液晶（TLC）热像技术，研究的靶板包括光滑靶板、针肋靶板以及带气膜出流孔的针肋靶板。冲击间距比为1.5，射流雷诺数范围为15 000~30 000。结果表明，针肋+气膜出流孔结构明显改善了下游区域横流的影响，明显提高了传热性能，靶板表面传热分布也更加均匀。相比于平板，当射流雷诺数为15 000时，针肋靶板和带气膜出流孔的针肋靶板端壁表面平均Nusselt数提升幅度最大，分别为6.3%和25.3%。针对双层壁冷却结构内射流冲击传热还开展了数值计算，通过采用SST （Shear Stress Transport）k-ω湍流模型计算分析获得了该双层壁冷却结构内的流动和传热特征。

Jet impingement heat transfer performance in a double-wall cooling structure with film effusion holes and pin fins

Multiple-jet impingement heat transfer performance in a double-wall cooling structure with pin fins and film effusion holes has been studied experimentally and numerically. Transient Liquid Crystal (TLC) thermography experimental method was used to explore the heat transfer characteristics on three target plates:flat plate, pin fin plate and pin fin plate with effusion holes. The jet-to-plate spacing was fixed to 1.5, and the Reynolds number based on the jet diameter ranges from 15 000 to 30 000. The experimental results show that the pin fin and effusion holes structure reduces the strength of the cross flow in the downstream region, improves and uniforms the heat transfer on the whole target plate obviously. When Reynolds number equals 15 000, there is a highest improvement of averaged Nusselt number on the endwall. Compared with that of the flat plate, the averaged Nusselt number of the pin fin plate and pin fin + effusion holes plate increases by 6.3% and 25.3%. For the numerical method, SST (Shear Stress Transport) k-ω turbulence model was employed to get an understanding of the flow structure and heat transfer on the pin fin and effusion holes surfaces.