低压离心叶轮小流量失速特性的实验观察

AN EXPERIMENTAL OBSERVATION ON STALL OSCILLATION AT LOW FLOWRATE IN A CENTRIFUGAL IMPELLER Dai Ji and Chen Jingyi

在一离心压缩系统喘振实验台上，对小流量工况下沿叶轮出口圆周的压力波动进行了动态测量。实验观测到离心叶轮在小流量工况下存在一种低于转速频率的、且非旋转类型的失速自激振荡，观察到这种波动在局部及个别瞬间是不稳定的。

An experiment was conducted to investigate the self-excited flow oscillation in a centrifugal fan impeller.The unsteady dynamic pressures were measured around the periphery of the impeller outlet with 8 high-response transducers.The experimental observation shows the existence of a lower frequency,nonrotating oscillation in the low flowrate conditions.The measurements also indicate that the oscillation is unstable at a short duration and at a local position,and the peripheral distribution of oscillation strength is non-uniform.The analysis shows that there may be some relationship between the self excited flow oscillation and rotating stall,especially during inception behavior of rotating stall.