液体火箭发动机试验脉动压力数据分析方法研究

针对液体火箭发动机试验脉动压力数据的特点，对脉动压力数据和相关振动测点数据进行快速傅里叶变换（FFT），频谱分析的结果能够有效判断发动机不稳定燃烧的声振类型。采用小波变换奇异点检测的方法，对启动段和关机段波动异常的脉动压力数据进行分析，结合相关振动测点的频谱信息能够在时域内准确定位奇异点位置，提取频域内的信息，有效判断推进剂燃烧情况和声振类型。分析结果表明上述方法在火箭发动机和组合件试验的脉动压力数据分析中具有重要的推广意义。

Research on Data Analysis Method of Fluctuating Pressure in Liquid Rocket Engine Test

According to the characteristics of fluctuating pressure data of liquid rocket engine test, fast Fourier transform(FFT) and wavelet transform are introduced in this paper. Through the fast Fourier transform(FFT)of the fluctuating pressure data and the related vibration data, the acoustic vibration type of the engine unstable combustion is effectively determined by the spectrum analysis results.Based on the wavelet transform singularity detection method, the abnormal fluctuating pressure data in the start-up and shutdown stages are analyzed.Combined with the frequency spectrum information of relevant vibration measurement points, the singular point position can be accurately located in the time domain, and the information in the frequency domain can be extracted to effectively judge the burning condition and acoustic vibration type of propellant.The analysis results show that the above methods can be widely used in the analysis of fluctuating pressure data of other type tests of engines and assemblies.