单级轴流压气机失速起始的数值模拟

Numerical simulation of stall inception in single-stage axial-flow compressor

基于某亚声单级轴流压气机试验台孤立转子环境下预失速行为的研究成果,进一步数值研究了该试验台单级环境下的失速起始过程.数值探针的监测结果表明,失速起始过程中单级轴流压气机的流动失稳始于转子叶尖部位,这与前期针对该试验台流动失稳的测量结果是一致的.对数值模拟的瞬态流场进行分析表明,先兆波的型式已从孤立转子环境下的"突尖"型转变为单级环境下的"多个小失速团"型,说明静叶的存在改变了近叶尖载荷的周向分布规律.然而,"叶尖二次涡"的形成与运动依然是"多个小失速团"型先兆波浮现的流体动力学机理.

Based on the investigation results involving pre-stall behavior in subsonic single-stage axial-flow compressor test rig under isolated-rotor environment, whole-passage simulations were further carried out to investigate the stall inception process under singlestage environment. The monitoring results from the numerical probes indicate that the local breakdown of flow-field of single-stage axial-flow compressor is initiated at rotor tip region during stall inception process. The simulation results were validated by available experimental data. Detailed instantaneous flow-field analysis demonstrates that the type of pre-stall wave is ＂multi-cell＂ disturbance under single-stage environment in contrast to ＂spike＂ disturbance under isolated-rotor environment, implying that the presence of stator alters the pattern of near-tip circumferential loading distribution. However, the flow mechanism for the emergence of ＂multi-cell＂ disturbance is still represented by the formation and movement of tip secondary vortex.