直肋对扩张型尾缘半劈缝气膜冷却特性影响的实验研究

To explore the film cooling performance of the cutback trailing-edge with straight-rib turbulence structures, the effects of the straight ribs on the adiabatic film effectiveness and heat transfer coefficient of the expanded cutback surface were studied using the pressure-sensitive paint technology and transient thermochromic liquid-crystal technology, respectively. The effects of the blowing ratio and the rib width on the film cooling performance of the three different expanded cutback surfaces were analyzed and compared in detail. The experimental results show that the addition of straight ribs has an adverse effect on the film coverage on the small expanded cutback surface, but only in the case at low blowing ratio. The straight ribs have a slightly promotion effect on the adiabatic film effectiveness for the large expanded cutback surface, while its adiabatic film effectiveness is always lower than that for the small expanded cutback surface. The heat transfer enhancement of the cutback surface by different rib widths is mainly affected by the shape of the expanded cutback surface. As the expansion of the cutback surface increases, the high heat transfer advantages of the case with wide-ribs gradually surpass the case with narrow-ribs. Compared with the primeval cutback trailing-edge, the wall heat flux of the cutback trailing-edge with straight ribs can significantly improve by a factor of 45%~100%. At the low blowing ratio, it is advisable to choose the case of the small expanded cutback surface with narrow-ribs, while the case of the large expanded cutback surface with wide-ribs should be selected at the high blowing ratio.