进气畸变对跨声速轴流压气机气动影响的机理研究

Mechanism investigation of aerodynamic effect on the inlet flow distortion in a transonic axial-flow compressor

利用插板模拟跨声速轴流压气机进口流场畸变.通过实验和数值模拟两种手段详细分析了进口畸变下跨声速压气机的流动特点、激波沿周向的分布以及压气机的失速机理.实验和数值模拟的结果表明:插板使压气机前的不同周向位置产生正、负预旋流动;转子前速度的周向分布沿轴向是不断变化的,在距离转子较近时,畸变区的轴向速度反而较大;气流在过渡区A(转子进入低压区)时为正预旋,为非激波区;在过渡区B(转子退出低压区)和畸变区时为负预旋,为强激波区;过渡区的泄漏涡最强,是不稳定流动的诱发区域.

An inlet flow distortion with plugboard was simulated. The flow-field char- acteristics, circumferential distribution of shock wave and stall mechanism were analyzed in detail. Experiment and numerical simulation were conducted. The experimental and numer- ical simulation results show that the positive and negative pre rotation were generated in front of the compressor at different circumferential respectively, and the circumferential dis tribution of velocity in front of the rotor constantly changed along axial direction. The axial velocity of distortion sector was larger near the rotor leading edge. The air flow was under positive pre-rotation in non-shock wave region at transition sector A where the rotor was ro- tated into the low pressure sector. It was under negative pre-rotation in strong shock wave region at transition sector B where the rotor was rotated out of the low pressure sector. The leakage vortex of transition sectors was stronger than any other sectors. So the transition sectors were the regions where unstable flow occurred in advance.