进气条件对扇形孔气膜冷却特性的影响

Effect of Inlet Condition on Film Cooling Performance of a Fan-shaped Hole

在横流进气条件下,基于气膜冷却平板实验研究了不同吹风比下横流比为0、0.2和0.4和入口(横流上游侧和下游侧)堵塞对扇形孔气膜冷却特性的影响。结果表明:横流比由0.4降到0.2时,扇形孔的气膜偏斜程度降低,气膜性能提高;横流比进一步降到0,气膜偏斜方向相反,偏斜程度反而增强,气膜性能降低;横流下游侧堵塞加剧了气膜偏斜程度,气膜冷却效果变差,而横流上游侧堵塞改变了气膜偏斜方向,增强了气膜覆盖效果。因此入口堵塞对扇形孔气膜冷却效率的影响程度与孔的位置和冷气流动条件有关。

Under the condition of cross-flow inlet,the effects of cross-flow ratios of 0,0.2 and 0.4 and inlet blockage(upstream and downstream sides of cross-flow)on the film cooling characteristics of fan-shaped holes under different blowing ratios were studied based on the film cooling plate experiment.Results show that when the crossflow ratio decreases from 0.4 to 0.2,the film deflection of the fan-shaped hole is reduced and the film performance is improved.But when the crossflow ratio approaches zero,the coolant deflects to the opposite side with performance decline.Blockage on the downstream side aggravates the film deflection and reduces the cooling effectiveness.Blockage on the upstream side reverses the coolant deflection direction and raises the coolant coverage.Effects of inlet blockage on film cooling effecive depend on the hole location and the coolant serving flow conditions.