Abstract: To further clarify the complex flow mechanism within a low-reaction compressor， unsteady simulations were conducted on the mid-span micro element of a low speed low-reaction aspirated compressor. Effects of the axial gap between rotor and stator on the aerodynamic performance of the aspirated compressor were studied in detail by 2D unsteady simulation. The results show that， as the axial gap is reduced， on the one hand， the influence of the downstream stator potential effect on the rotor is more pronounced， which results in an intensified pressure fluctuation adjacent to the rotor trailing edge and an aggravated wake decay; on the second hand， as transported through the stator passage， the rotor wake presents a stronger tendency to be discrete and its interactions with the stator suction side boundary layer is aggravated， which leads to an increase of stator throughflow loss by 12.976% and a decrease of the whole stage efficiency by 0.16%.

Key words: Low-reaction compressor；Axial spacing；Unsteady simulation

摘要： 为进一步明晰低反力度压气机内部复杂流动机理，以低速低反力度吸附式压气机叶展中截面微元段作为研究对象，借助非定常数值模拟的方法，探讨了变轴向间距对低反力度压气机气动性能的影响。研究结果显示，轴向间距缩短后，转子受下游静子势流的作用更为明显，近尾缘区域静压波动幅度增加、尾迹亏损加剧；在静子流道输运过程中，转子尾迹呈现出明显的离散趋势且与静子吸力面附面层干涉作用加剧，这导致静子通流损失增加12.976%，整机效率降低了0.16%。

关键词: 低反力度压气机；轴向间距；非定常数值模拟