吹风比对涡轮动叶型面气膜孔流量系数的影响

Experimental Investigation of Discharge Coefficients of Film Cooling Hole on Turbine Blade

对涡轮工作叶片表面不同位置气膜孔的流量系数进行了系统的测量 ,在不同吹风比和雷诺数下测得了流量系数值 ,并分析了各种因素对流量系数的影响程度。结果表明 ,在不同位置气膜孔流量系数分布规律有较大区别 ,孔排位置一定时 ,流量系数主要由吹风比决定。

We investigated discharge coefficients of film cooling hole on Chinese designed turbine blade in a large scale low speed cascade. There were eight rows of film cooling holes——one of them on suction surface, two on pressure surface and the rest in leading edge——on the blade. We studied effects of varying injection blowing ratio ( R B) and Reynolds number ( Re ) on discharge coefficient. The studied parameters were in the ranges of 0.5~2.5 for R B and 2.5×10 5~4.5×10 5 for Re . The experimental data, as shown in Figs.3(a) through 3(f), show that the discharge coefficients increase rapidly with increasing R B. We observed no significant effect of variation of Re on the variations of discharge coefficients. The magnitudes of the discharge coefficients are strongly dependent on the locations of the holes. The discharge coefficients for the holes on both surfaces, suction and pressure, as shown in Figs.3(a), 3(b), 3(e), and 3(f), are almost at the same level. The discharge coefficients for the holes in leading edge, as shown in Figs.3(c) and 3(d), are much lower, particularly in the case of low R B.