涡轮叶片表面气膜冷却效率的实验研究

采用放大的叶片模型，利用大尺寸低速线性叶栅风洞进行实验，测量了涡轮导向叶片表面不同位置单排气膜孔的气膜冷却效率，研究了孔排位置、吹风比及来流雷诺数的影响。风洞实验段由3个叶片组成，其中中间的叶片为试验叶片，由优质木材制成。试验叶片表面上开有15排气膜孔，其中吸力面3排，前缘区6排，压力面6排。实验的参数变化范围是：基于叶片弦长的来流雷诺数250000-450000，吹风比0．5-2．5。结果表明，由于气膜孔排位置的不同，其下游冷却效率受来流雷诺数及吹风比影响的变化趋势也有所不同。

An experimental investigation of film cooling effectiveness on the surface of turbine blade

Film cooling effectiveness of single film row at different locations on turbine blade surface was studied experimentally. A three-blade liner cascade in a large-scale low-speed opening wind tunnel was used in the experiment. There were 15 rows of film cooling holes at the surface of middle blade which was made of high quality wood and three rows on the suction surface, six rows on the leading edge and six rows on the pressure surface. Film cooling effectiveness on the blade surface was measured for the cases with mainstream Reynolds number from 250000 to 450000 and blowing ratio from 0.5 to 2.5. The influences of Reynolds number, blowing ratio and the location of film cooling holes on film cooling effectiveness were described.