用小波变换对机匣处理抑制旋转失速的机理研究

MECHANISM INVESTIGATION ON CASING TREATMENT FOR RESTRAINING ROTATING STALL BY MEANS OF WAVELET TRANSFORM

本文利用小波变换对轴流压气机旋转失速时的压力信号进行时频分析。通过Ｍｏｒｌｅｔ连续小波变换，详细分析压气机失稳过程中非定常信号的变化，并研究旋转失速初始扰动信号在处理机匣气室中的局部行为。通过对比实壁机匣与处理机匣的失速初始信号相干波形的结构特性，发现不同机匣结构对相干波形结构中压力脉动信号的不同影响，提出处理机匣抑制旋转失速初始扰动发展的机理。

Wavelet transform,as a tool for signal analysis,is applied to analysis of compressor rotating stall signals.With the Morlet wavelet transform,the time-evolution of the unsteady signals during the stall inception and the local behavior in the casing treatment plenum are investigated.By comparison with structure characteristics of the coherent waves in the casing without treatment,it is shown that the casing treatment do has different influences on pressure impulse signals.A mechanism for restraining perturbations of stall inception via casing treatment is proposed.