气动参数对前缘气膜冷却效率影响的实验

针对叶片前缘结构特点,建立了前缘气膜冷却实验台,实验模型由带气膜孔的半圆柱面和平板组成.密度比为1和1.5,动量比变化范围为0.5~4,湍流度为0.4%和8%.结果表明,随着动量比的增加,冷却效率减小.在低动量比下,湍流度的提高使径向平均冷却效率降低.随着动量比的增加,湍流度对径向平均冷却效率的影响减弱.低动量比下,密度比的增加使径向平均冷却效率减小;高动量比下,密度比的增加使径向平均冷却效率增大.

Influence of aerodynamic parameters on film cooling effectiveness on the vane leading edge

Film cooling effectiveness on the leading edge with one row of holes is studied experimentally.The model was a blunt body with a half cylinder leading edge and two flat plates.One row of holes was located at the place 2 hole pitches from the stagnation line.Foreign gas injection was used to obtain a density of approximately 1.5.High turbulence intensity was produced by a passive grid.Momentum ratios varied from 0.5 to 4.The result indicates that film cooling effectiveness decreases with increasing momentum ratio.Spanwise averaged film cooling effectiveness is reduced by high mainstream turbulence intensity with momentum ratio of 0.5 and the mainstream turbulence effect is diminished with increased momentum ratio.Film cooling effectiveness along the film cooling hole is significantly reduced by high mainstream turbulence level.Spanwise averaged film cooling effectiveness decreases in the case of low momentum flux ratio and spanwise averaged film cooling effectiveness increase in the case of high momentum flux ratio because of foreign gas injection.