气膜孔局部堵塞对叶片压力面冲击-扰流柱-气膜结构综合冷却效率的影响

运用数值模拟方法研究了气膜孔局部堵塞对叶片压力面上射流冲击-扰流柱-气膜结构综合冷却效率的影响，重点分析了堵塞位置和堵塞比的影响。研究结果表明：无论是气膜孔内无堵塞还是存在局部堵塞情形，随着吹风比增大，综合冷却效率均呈现逐渐增大的趋势；在低的吹风比下，气膜孔出口-尾缘局部堵塞的综合冷却效率略低于无堵塞气膜孔，而在气膜孔进口-前缘和气膜孔出口-前缘的局部堵塞则导致综合冷却效率有较为轻微的上升；在高吹风比下，位于气膜孔出口-前缘和气膜孔进口-前缘的局部堵塞能够抑制气膜射流与主流相互作用所形成的卵形涡，从而冷却效率下降较少，而气膜孔出口-尾缘的局部堵塞则导致综合冷却效率降低较多；堵塞比对壁面沿程综合冷却效率的影响呈现非单调的变化趋势，这是由于冲击-扰流柱-气膜整体式冷却结构的冷却效果取决于内部强化传热和外部气膜防护的多重作用机制。

Effects of partial blockage inside film holes on overall cooling effectiveness of an integrated impingement-fin-film cooling configuration on blade pressure side

An investigation is performed numerically to reveal the effects of partial blockage inside film holes on the overall cooling effectiveness of an integrated impingement-fin-film cooling configuration on the blade pressure side, mainly focusing on the effects of blockage position and blockage ratio. The results show that the overall cooling effectiveness increases gradually with the increase of blowing ratio in both cases of no blockage and partial blockage film holes. With low blowing ratio, the partial blockage located at the trailing edge of film-hole exit decreases weakly the overall cooling effectiveness, whereas the partial blockage located at the other positions, including the leading edge of the film-hole inlet and the leading edge of the film-hole exit, increases the overall cooling effectiveness weakly. With high blowing ratio, the partial blockages located at the leading edge of the film-hole exit and the leading edge of the film-hole inlet could mitigate the kidney vortices due to the mainstream-coolant jet interaction, leading to a weak improvement of the overall cooling effectiveness, whereas the partial blockage located at the trailing edge of the film-hole exit results in reduction of overall cooling effectiveness to some extent. In general, the influence of the blockage ratio on the overall cooling effectiveness is not simple as the cooling effectiveness of the integrated impingement-fin-film configuration depends on multimechanisms of internal heat transfer enhancement and external film coverage.