横向槽横向宽度对气膜孔冷却性能影响的数值研究

Numerical Simulation on the Effect of Transverse Width of Transverse Slot on Film Hole Cooling Performance

采用数值模拟的方法,研究带横向槽的气膜孔冷却结构槽横向宽度对气膜孔下游平均冷却效率的影响规律。对通过气膜孔次流的流场、垂直于主流截面上的局部速度矢量和温度分布、近壁面的冷却效果和气膜孔下游平均冷却效率进行了分析,发现槽横向宽度越小,气膜孔对冷流的束缚作用越强,使冷流以较大动量从孔中喷射出,导致冷流的贴壁性较差,气膜孔下游的平均冷却效率越低;槽横向宽度越大,冷流在气膜孔出口处有一定的膨胀,减小了其向上喷射的动量,使冷流的贴壁性更好,气膜孔下游的平均冷却效率也越高。

This paper investigated the influence of different width of transverse slot to average cooling effectiveness of cooling structure with transverse slot by numerical simulation.The flow field of cooling air,the distributing of local velocity vector and temperature on section of vertical mainstream,near wall cooling effectiveness and average cooling effectiveness of downstream were analyzed.It was found that the slot with the small transverse width,the slot had more binding effect on cooling air which ejected from film hole with more momentum,cooling air had little adhibiting effect,the down stream of film hole had lower cooling effectiveness.While the slot with the bigger transverse width,the cooling air which had little momentum expand at the film hole exit had better adhibiting effect,the film cooling hole had higher average cooling effectiveness.