对不同转角扩压叶栅内弯叶片的数值模拟

Numerical simulation for the influence of bowed blade in compressor cascades with different turning angles

关键词:  航空发动机  压气机  叶栅  折转角+  叶片  结构

Key words:  Aircraft engine  Air compressor  Cascade  Turning angle+  Blade  Structure

摘要:

通过数值模拟,分析了叶片周向弯曲对不同转角的压气机叶栅内分离结构和叶栅损失系数的影响。折转角分别为37,°46°和54°;冲角分别为±5°和±10°,弯角分别为±10,°±20°,±30°。结果表明,在不同折转角下,叶片正弯的表现不同:折转角较小时,正弯增强了吸力面的二次流,叶栅总损失增加;中等折转角时,叶片正弯可以有效遏止角区分离,并改善吸力面分离型态;大折转角时,较小的叶片正弯可以改善流动,但弯角大于20°时,流动重新恶化。反弯使得叶栅内角区分离趋势增加,气动性能明显降低。不同冲角下,弯角对损失影响的变化趋势基本相同,只是正冲角增强了这种趋势,负冲角减弱这种趋势。

Abstract:

A numerical simulation was performed to analyze the effect of bowed blade on the separation structures and the energy losses in the compressor cascades with different turning angles.The turning angles were 37°,46°,54°,respectively.The bowed angles were ±10°,±20°,±30°,and the incidence angles were ±5°,±10°,respectively.The results show that the influence of positive bowed blade is different with the variation of the turning angles.If the turning angle is low,the secondary flow on the suction surface as well as the loss increases.If the turning angle is moderate,it restrains the corner separation,and changes the separation configuration.If the turning angle is high,a low positive bowed angle improves the performance.But the flow becomes worse again if the bowed angle exceeds 20°.The negative bowed blade results in the flow separation and the flow performance is reduced remarkably.The varieties at different incidences are similar.The tendency strengthens at positive incidence and weakens at negative incidence.