轴流压气机脉动压力信号旋转失速特征分析

发布时间：2018-04-12 13:11

本文选题：轴流压气机 + 旋转失速　；参考：《南京航空航天大学》2011年硕士论文

【摘要】：轴流压气机旋转失速是航空发动机常见气动不稳定现象之一。识别轴流压气机失速信号特征对于认识航空发动机失速的产生和发展机理以及抑制航空发动机失速问题并对其进行主动控制具有非常重要的意义。以往的信号处理方法对失速前后特征的识别做出了很大贡献,但是鉴于失速特征产生和发展机理极其复杂,所以对失速的研究一直在不断深入。本文主要应用三种方法来对失速特征进行分析。具体工作如下: 1.初步学习并讨论了轴流压气机的压力测试方案。并且根据测得脉动压力的信号特点设计了低通FIR滤波器。 2.应用互相关分析和同频检测方法分析旋转失速特征如失速团数目、失速团传播速度。结果表明该方法受噪声干扰无法精确确定时延,只适用于时延较长的低速和中速轴流压气机。高速轴流压气机会出现失速特征频率高于转子频率若干倍的高频失速,而用互相关分析方法无法准确求取失速团在两个传感器中传播的时延,为了解决该问题本文利用同频检测原理求取出失速信号的特征频率的时延,来对压气机高频失速的失速团数目进行识别。 3.将脉动信号的相位和幅值特征通过极坐标进行可视化,对轴流压气机的失速特征进行分析。在极坐标中展示周向压力波动,可以较准确、直观的观察到失速团的数目;通过极坐标图形化脉动压力波动分析流场压力从正常工况到失速工况的规律可以对压气机的失速先兆进行预判。经过大量的试验数据分析,这种方法在分析失速团数目方面较相关分析等方法更加准确、直观;另外,本文还对压气机喘振的时域特征和频域特征进行了一定的分析。 4.利用Matlab中GUI界面开发了一个简单实用的分析软件。该软件具有单/多通道信号时、频域显示、信号滤波、信号谱分析、失速团数目识别等功能。经过测试表明该软件可准确、方便的用于轴流压气机的失速特征分析。
[Abstract]:Axial flow compressor rotating stall is one of the common aero-engine aerodynamic instability phenomena.It is very important to recognize the characteristics of stall signal of axial compressor for understanding the generation and development mechanism of aeroengine stall and to suppress the stall problem of aeroengine and to control it actively.The previous signal processing methods have made a great contribution to the recognition of the features before and after stall, but because of the extremely complex mechanism of the occurrence and development of stall characteristics, the study of stall has been continuously in-depth.In this paper, three methods are used to analyze the stall characteristics.The specific work is as follows:1.The pressure test scheme of axial compressor is studied and discussed.A low pass FIR filter is designed according to the characteristics of the measured pulsating pressure signal.2.The characteristics of rotating stall, such as the number of stall clusters and the propagation velocity of stall clusters, are analyzed by using cross-correlation analysis and the same frequency detection method.The results show that the method can not accurately determine the delay due to noise interference, and it is only suitable for low speed and medium speed axial compressors with long delay.The stall characteristic frequency of high speed axial flow compressor will be several times higher than the rotor frequency. However, the time delay of stall mass propagating in two sensors can not be accurately calculated by cross-correlation analysis.In order to solve this problem, the time-delay of characteristic frequency of stall signal is obtained by using the principle of simultaneous frequency detection to identify the number of stall clusters in high frequency stall of compressor.3.The phase and amplitude characteristics of the pulsating signal are visualized by polar coordinates, and the stall characteristics of the axial compressor are analyzed.The number of stall clusters can be observed more accurately and intuitively by displaying the circumferential pressure fluctuation in polar coordinates.Based on the analysis of fluctuating pressure fluctuation in polar coordinates from normal condition to stall condition, the preseason of compressor stall can be forecasted.After a lot of experimental data analysis, this method is more accurate and intuitive than the correlation analysis in analyzing the number of stall clusters. In addition, the time-domain and frequency-domain characteristics of compressor surge are also analyzed in this paper.4.A simple and practical analysis software is developed by using GUI interface in Matlab.The software has the functions of frequency domain display, signal filtering, signal spectrum analysis, number identification of stall groups and so on.The test results show that the software is accurate and convenient for the stall characteristic analysis of axial compressor.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH453

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