开槽气膜孔结构对气膜冷却和流动特性的影响

运用数值模拟的手段,从流动特性和冷却特性两方面评价了各种开槽气膜冷却孔结构的优劣。从流动的机理揭示了在相同的槽深下,不同的横槽结构对改善气膜冷却效率和流量系数的影响,并比较了在气膜孔出口和入口均开有横槽后对流动和冷却特性的影响。结果表明：开横槽后,气膜孔出口下游的冷却效率得到不同程度的改善,吹风比越大,改善的程度越明显。在横槽下游5D-10D的范围内,冷却效率的改善程度最大;在气膜孔出入口处均开有斜横槽的结构和用圆角过渡气膜孔入口处的横槽均是提高气膜冷却效率和减小气膜孔流动阻力的有效措施,而在气膜孔出口处的横槽用圆角过渡则不利于改善气膜冷却效果。

The Influence of Trenched Film Hole Configurations on Film Cooling and Flowing Characteristics

The cooling and aerodynamic performance of different film cooling holes with one end or both ends embedded in transverse slots are investigated numerically in several blowing ratios,to reveal the effects of different slot configurations with the same slot depth on the film cooling performance and aerodynamic performance from the flowing mechanism.The results show that making the film holes embedded in transverse slots can improve the film cooling effectiveness,especially for high blowing ratios.The best improvement region is the 5D-10D downstream edge of the slot.Compared to the baseline untrenched configuration,the cooling performance and the aerodynamic performance of the holes with both ends embedded in inclined slots is superior to the holes with only exit trenched.The filleting for the film hole inlet avail the improvement of the cooling effect,but not for the film hole outlet.