针对低速单转子轴流压气机,采用节流阀函数进行了突尖型失速过程的数值模拟研究,以叶顶泄漏流周期性非定常波动及其周向传播特性为切入点,以失速过程中典型时刻为例,分析了失速过程中压气机内部流动的发展和演变特征。伴随压气机节流进入突尖型失速的过程,叶顶泄漏流周期性非定常波动频率和周向传播速度减小;当叶顶泄漏流轨迹与叶顶前缘额线平齐时,出现突尖型失速先兆,其流动特征表现为起始于叶片吸力面并延伸至机匣的双旋涡结构;当叶片同时出现尾缘回流和前缘溢出时,标志压气机进入完全发展的突尖型失速状态。
By adopting the model of throttling valve in numerical simulation, the evolution process of spike type rotating stall in a low speed isolated axial compressor rotor is investigated. The periodic oscillation of unsteady tip leakage flow (TLF) and its circumferential propagation provide an entry point for this study. The characteristics of compressor internal flow at some typical time instants were analyzed. With compressor throttled into rotating stall, the periodic oscillation frequency of unsteady TLF and its circumferential propagation speed decrease. When the trajectory of TLF is aligned with the rotor leading edge plane at blade tip, the spike type stall precursors occur. Their structures are of twin vortexes, which stemming from the blade suction sides and extend to the casing. When the backflow of TLF at the rotor trailing and also the spillage at rotor leading appear at the same time, the fully developed rotating stall comes into being.