摘要
当压气机叶片负荷很大时,吸力面会发生严重的分离,在此基础上若正攻角继续增加,则叶片整个吸力面都可能发生分离,吸力面分离起始点不断向叶片前缘移动,可能出现类似外流中大攻角三角翼的非对称结构。利用数值模拟方法,采用边界层吹气技术,研究了具有68°折转角的矩形缝隙叶栅在不同攻角条件下的流动特点和气动性能。计算结果表明,叶片采用压力面到吸力面的吹气槽,在正攻角较大时能有效控制扩压叶栅中的附面层分离,消除原型叶栅中非对称的旋涡结构,降低气动损失,其中在+4°攻角下可将能量损失系数降低约12.5%,同时可使流通能力大大改善,扩大稳定工作范围。
There exits large scale boundary layer separation near suction surface of the ultra highly loaded compressor cascades. At this basement, if the positive incidence was increased, the boundary layer separation may exit on the whole suction surface, and also the separation point would move forward to the leading edge. The unsymmetrical vortex structure may be presented. By numerical simulation and boundary blowing method, the flow characteristics and performances of a certain rectangular compressor with slot which has a 68° geometry turning angle is studied in this paper under different incidences. The results show that the boundary separation under large positive incidence could be effectively controlled by using the blowing slot from pressure side to suction side. The unsymmetrical vortex structure is eliminated and pressure loss is reduced. When the positive incidence reaches four degree, the energy loss could be reduced by 12.5%. The flow capacity and surge margin are also enlarged.
出处
《汽轮机技术》
北大核心
2009年第6期445-447,共3页
Turbine Technology
关键词
大折转角
附面层分离
缝隙叶栅
流动控制
large turning angle
boundary layer separation
cascade with blowing slot
flow control
