利用三角形突片改善气膜冷却效率的数值研究

Numerical Investigation on Improvement of Film Cooling Effectiveness Using Delta-Shaped Tabs

运用数值计算方法对带有平行于冷却壁面、且覆盖部分气膜孔面积的三角形突片气膜冷却结构,在不同吹风比下的流动过程和冷却效率进行了数值研究,以揭示突片对改善气膜冷却效率的影响。在突片的作用下,射流向主流的垂直穿透能力有一定程度的降低,在气膜孔下游,二次流能够更好地贴附壁面,气膜冷却效率均有不同程度的改善,而且随着突片堵塞比的提高,冷却效率的提高幅度越大,并且在高吹风比下的影响更为显著。

The flow fields and cooling effectiveness of the film cooling from a row of cylindrical angled holes with triangular tabs are investigated numerically in several blowing ratios,to reveal the effects of tabs on the film cooling performance. The tabs are located along the upstream edge of the holes and placed parallel to the film cooling surface covering a part of the hole. The results show that the tabs improve film effectiveness due to the penetration of the film secondary flow into the cross flow is suppressed under the action of the tabs. And the film cooling effectiveness improvement is significant in the cases of higher blowing ratio and higher tab blocking ratio.