从端壁动态压力场看压气机转子尖区流动

UNSTEADY STATIC PRESSURE FIELD ON THETIP ENDWALL OF AN AXIAL-FLOWCOMPRESSOR ROTOR MSSAGE

用高频压力传感器测量了低速单级压气机转子叶尖动态压力场。结果表明，转子叶背附面层径向潜流使得叶背附近存在一个高压带。叶背角区和叶盆角区的气流交混造成通道中部具有甚至不低于叶盆处的高压力。两个高压区都随流量的减小而扩大，并随流向逐渐融合，反映了叶背附面层径向潜流和中部气流交温的发展。设计状态下，泄漏涡是造成转子叶尖压力脉动的主要因素，形成的高水平压力脉动区随流向呈喇叭形逐渐扩大，约在一半弦长处脉动最强。近失速状态下，叶背前部角区中强叶面附面层潜流及与强泄漏流和端壁附面层的交混造成大范围的强压力脉动区，局部扩展到整个通道，通道中部叶背附面层很有可能发生分离。

Unsteady static pressure field on the tip endwall of an axial-flow compressorrotor passage was measured using a micro high frequency pressure transducer. Distributionsof phase-locked average and random fluctuation of the pressure were analyzed to help understand the tip flow in both design and near stall condition. The results show that, in designcondition, a high pressure area extending along the suction side while another one existingin mid-passage, both enlarge with the mass flow decreases. In design condition, pressurefluctuation is mainly caused by the tip leakage vortex, with the highest level at half-chord.In near stall condition, the pressure fluctuation area is even across the whole blade passagedue to the very strong leakage flow. The distributions of average pressure and fluctuationpressure both confirm the separation of the boundary layer on the suction surface.