整体涡旋流畸变下的压气机失速机理分析

为了研究跨声速压气机在整体涡旋流畸变下的失速机理,采用数值仿真方法对Stage35进行了整级数值模拟,研究了叶片通道流场中触发压气机失速的关键因素,分析了不同转速下,叶顶泄漏涡和径向涡在旋流畸变条件下的变化情况。结果表明:同向整体涡能抑制叶背流动分离,使径向涡体积减小,叶顶泄漏涡减弱,叶顶通道堵塞程度减小,压气机稳定裕度增大;出现反向整体涡时,叶背气流分离加剧,径向涡体积扩大,低转速下,泄漏涡增强,堵塞区面积增大,高转速下,泄漏涡变化不大,但径向涡体积扩大引起流体向叶尖堆积,形成大面积的吸力面尾缘低速区,更容易导致压气机失稳。

An Instability Mechanism Analysis with Compressor under Condition of Bulk Swirl Distortion

Numerical simulation of stage 35 with bulk swirl is carried out using CFD technology for the convenience of analyzing the instability mechanism of transonic compressor. The key factors triggered instability of the compressor are discussed such as leakage vortex and radial vortex at different rotation speed and swirl distortion condition. The results show that positive bulk swirl restrains flow separation of suction side, the leakage vortex, volume of radial vortex of compressor are decreased in positive bulk swirl. The flow separation, radial and leakage vortex and blocking area are increased with low rotation speed in negative bulk swirl. At high rotation speed, negative bulk swirl has little influence about leakage vortex, but the volume of radial vortex is greatly increased to drive flow gathered on blade tip to cause large low speed area in the tail of suction side, causing the instability of compressor strictly.