基于时频—小波分析的压气机失速过程研究

Study of Stall in the Compressor Based on the Time-Freqency and Wavelet

采用时频—小波分析的方法,针对某型发动机的八级轴流压气机级间压力信号,提取失速先兆及发展信息。结果表明,在失速前的阶段,不同的频率段表现出不同的失速先兆成分;并检验了失速时刻信号的奇异性,最后确定了最先失速级。

By means of the pressure signals of a certain research engine which has an eight axial stage compressor.A method of time-frequency analysis is presented in the paper.Information on the stall inception and development,which has some correlations with the onset-frequency and stall-frequency can be obtained during the engine operations.Therefore,the two main frequencies at the stall inception can be observed in the time-frequency plots.In order to identify the signal of the onset of stall accurately,this paper introduces the technique of the wavelet analysis,and provides an example of the 1st-6th compressor stage signals which are decomposed by Daubechies wavelets.The result indicates that different frequencies show different stall inception prior to the stage stall,and proves the singularity of the signal of stall.The stage of the first stall is ascertained by this method in the paper.