采用机匣壁动态压力测量技术对某高速亚音轴流压气机转子中转数可压条件下不同工况点叶尖流场进行了测量。在对近失速工况点试验测量结果进行详细分析的基础上,结合全通道非定常的数值模拟对试验观察到的流动现象进行了解释。结果表明:随着工况点向失速边界点推进,叶尖区出现的非定常流动现象(旋转不稳定性)增强,且该非定常流动现象的活动频率随流场的调整在一定带宽范围内变化;通过非定常数值模拟结果与试验测量结果的对比分析表明,叶尖通道中以一定周期活动的TSV的出现是旋转不稳定性流动现象出现的流体动力学机制。
Instantaneous casing static pressure measurements were conducted to explore the flow characteristic at different stable operating conditions for a small-scale axial flow compressor rotor at 54% design speed compressible flow condition. Fast Fourier transformation (FFT) of instantaneous pressure signals for 4 near-stall operating points (gk4, nsl through ns3) indicated the rotating instability (RI) further strengthened with flow rated decreased to the last stable point of ns3. The active period/frequency of RI varied with time according to a further short time Fourier transforma- tion (STFT) analyses. The simulated unsteady flow fields at near stall operating points exhibited the similar unsteady flow phenomenon to that of measurements. The detailed flow field analyses demonstrated that the activities of tip secondary vortex (TSV) in tip passages were probably the flow mechanism by which RI emerged.