小波方法分析小流量喷气影响两级低速轴流压气机失速特性的动态效果研究

THE INVESTIGATION OF THE DYNAMIC EFFECT ON THE STALL CHARACTERISTICS BY MICRO-FLOW-RATE PROJECTION IN A LOW-SPEED TWO-STAGE AXIAL COMPRESSOR

本文用连续小波变换和二维图像处理方法对三个不同角度的喷气试验数据进行了分析．通过对比分析，连续小波变换发现失速前转速频率成分的能量在两级动叶前的信号中出现波动现象，而这种波动的强度与喷射角有关；二维小波图像分析发现，压力场中相对于叶片通道而言的大尺度奇异性均在失速前呈波动性增强，这种波动以接近转子转速沿压气机周向旋转，喷射角度对失速前的奇异性及其波动程度有明显影响．一维小波方法和二维方法的结果相互对应，但二维方法更加具有优势．

This paper presents the result of projection on a low-speed two-stage axial compressor at three directions analyzed through the continuous wavelet transform(CWT) and 2-D wavelet image processing method. It is found by CWT that the energy of rotor frequency begin to fluctuate, the strength of the fluctuation is relevant to the angles of projection. In the pressure field, the 2-D wavelet method find that the fluctuation of the singularity at blade passage scale become stronger before stall. The wave of the fluctuation rotates around the rotor at the speed, which is near the rotor speed. The angle of projection affects the singularity and the strength of fluctuation. The results of both methods are concerned, but the 2-D method is better.