某轴流式压气机气动不稳定的相关积分分析

Correlation-integral Analysis of the Aerodynamic Instability of an Axial-flow Compressor

研究了某轴流式压气机节流试验中的气动不稳定问题。运用非线性的相关积分方法对压气机机匣壁面沿程静压信号进行了分析。结果表明,压气机静叶通道机匣壁面给定点静压信号的相关积分值随着发动机工作状态的不同有规律的发生变化,反映了对应位置的流动分离状况;压气机沿程各级静叶通道机匣壁面静压的相关积分值可以反映不同工况时压气机各级叶尖的流动匹配情况;压气机第一级静子机匣壁面静压信号的相关积分值可以反映中低转速工况下放气带开关状态对转子端壁流态的影响。研究还表明,压气机静子机匣壁面沿程静压信号的相关积分分析是进行压气机气动稳定性监控诊断的一种有效手段。

Investigated was the aerodynamic instability problem of an axial-flow compressor during throttling tests.A nonlinear correlation-integral method was employed to analyze static pressure signals along the compressor casing-wall surface.The results of the analysis indicate that correlation-integral values of the static pressure signals at a given point of the compressor stator passage casing-wall surface will undergo regular changes,depending on the engine operating conditions,and reflect the flow separation conditions at corresponding locations.The correlation-integral values of static pressure at various-stage stator channel casing-wall surface along the compressor flow passage can reflect the flow matching status at the blade tip of the various compressor stages under different operating conditions.The correlation-integral values of the static pressure of the compressor first stage stator casing-wall surface reflect the impact of the bleed valve's switching state on the rotor end-wall flow regime at intermediate and low-speed operating conditions.The study conducted by the authors indicates that the correlation-integral analysis regarding the above-mentioned static pressure signals can serve as a kind of effective means for monitoring and diagnosing the compressor aerodynamic stability.