冲角变化对弯掠压气机叶栅壁面静压分布的影响

实验研究了冲角变化对不同掠型叶片组成的平面扩压叶栅壁面静压分布的影响。结果表明,变冲角时弯掠叶栅端部横向、径向及流向压力梯度分布改善,正冲角时端壁与吸力面附面层相互作用减弱,避免了低能流体在吸力面角区的积聚及分离,同时也使得中径附近损失有所增加,但其总损失没有明显增大;负冲角时弯掠叶栅中径附近的损失增加在总损失中占主导地位,气动性能下降。在较大正冲角时弯掠叶栅仍能保持角区流动的稳定,若增大中径处的设计冲角能够获得更好的气动性能。

Influence of incidences on the distribution of staticpressure of swept-curved compressor cascades

Four different swept rectangular compressor cascades were experimental studied to clarify the effect of incidences on the cascade aerodynamic performances. The static pressure distribution on the surfaces of cascades at different incidences shows the swept-curved cascade improved the pitchwise, spanwise and axial pressure gradient near endwall while the incidence angle changed.At positive incidence angles, the improved pressure gradient delays the interaction of endwall and suction surface boundary layers, avoids the low-energy fluid accumulating in the suction corner region and thereby flow separation occurring there,while loss increases at midspan, the total loss increases insignificantly.At negative incidences,the energy loss at midspan of swept-curved cascade is dominant and the overall aerodynamic performance decreases. The swept-curved blade is able to sustain the flow in the corner even at higher incidence angles.Better performance can be achieved by increasing the design incidence angle at midspan.