透平叶片前缘双排交错孔气膜冷却数值模拟

Numerical simulation of film cooling at the leading edge of a turbine blade with two rows of staggered holes

为了解前缘冷气喷射对透平叶片的气膜冷却特性,对圆柱形前缘双排交错孔气膜冷却进行了全三维N-S方程数值模拟,第一排孔射流角度分别为15°、20°和25°,第二排孔均为20°。计算域网格采用FNM(full non-matched)形式的多块结构化网格。研究了射流与主流的流动机理,分析了不同吹风比下不同孔排结构对壁面冷却效率的影响。计算结果表明:第一排射流角度的变化对前缘绝热效率分布的影响非常明显,壁面气膜冷却效率随吹风比的增大而升高。

Film cooling characteristics were numerically analyzed on the circular leading edge with two rows of staggered holes based on a 3-D N-S equation solver.The injection angles of the first row of holes were 15°,20°,25° to the lateral direction,respectively,and the injection angle of the second rows of holes is 20°.A full non-matched（FNM） form multi-block structural mesh was used for the computational domain.The flow field mechanisms resulting from the interactions between the cooling jets and the free stream were examined with the effect of the adiabatic effectiveness expounded at different blowing ratios and locations of coolant holes.The results show obvious influences of different injection angles of the first row of holes on the cooling effectiveness with the film cooling effectiveness being improved with increasing blowing ratio.