冷气横流下复合角扩张孔的气膜冷却特性研究

Investigation of the Film Cooling of the Fan-Shaped Hole With Compound Angle Under Coolant Crossflow Condition

本文采用数值模拟方法研究了冷气横流方向对带复合角后倾扇形孔气膜冷却特性影响。结果表明,孔进口横流对气膜孔内部流动及外部冷却影响显著,尤其在大吹风比下。小吹风比时,不同横流方向与大腔进气的冷效基本一致。大吹风比时,孔进口横流的作用凸显,平行横流逆流和垂直横流顺流的气膜冷效显著下降,与大腔进气相比面积平均气膜冷效最大降幅达23%。在流量系数方面,顺流进气的流量系数远高于逆流进气,最大增幅达30%。

tThis paper investigates the impact of crossflow orientation on the film cooling characteristics of laidback fan-shaped holes with compound angles using numerical simulation methods.The results demonstrate that the crossflow at the hole inlet significantly infuences the internal flow and external cooling of the film holes,particularly at high blowing ratios.At low blowing ratios,different crossflow orientations exhibit similar cooling effectiveness as the plenum condition.However,at high blowing ratios,the effect of crossflow at the hole inlet becomes prominent.The film cooling effectiveness decreases significantly for the parallel counter crossflow and perpendicular crossflow.Compared with the plenum condition,the area average film cooling effectiveness decreases by 23%.In terms of the discharge coefficient,the discharge coefficient for the inline flow is much higher than that for the counter fow,with a maximum increase of 30%.