基于Hilbert-Huang变换的液体火箭发动机涡轮泵故障分析

Fault analyses of liquid rocket engine turbopumps based on Hilbert-Huang transforms

涡轮泵是液体火箭发动机(liquid rocket engine, LRE)推进系统的重要组成部分。涡轮泵故障也是LRE故障的主要来源。Hilbert-Huang变换(Hilbert-Huang transform, HHT)具备良好的自适应精确分析非平稳数据的能力。通过对真实的LRE试验数据的分析表明:采用信号包络非闭合镜像延拓的方法能有效解决经验模态分解(empirical mode decomposition, EMD)分解过程中出现的端点飞翼问题;采用HHT分析方法,对本征模态函数(intrinsic mode function, IMF)进行Hilbert变换得到时频域的Hilbert能量分布频谱图以及对IMF函数进行重构后的时间-幅值图能在时域和频域内自适应精确分析液氧涡轮泵振动数据,对涡轮泵的故障进行诊断与分析。该方法在火箭发动机和其他组合件试验数据分析和故障定位中具有重要的应用和推广价值。

Turbopumps are important in liquid rocket engine(LRE) propulsion systems. Turbopump failures are also the main cause of LRE failures. The Hilbert-Huang transform(HHT) has been used to adaptively and accurately analyze non-stationary data. An analysis of real LRE test data showed that the end flying wing problem in empirical mode decomposition(EMD) can be effectively solved using the signal envelope non closed image extension method. The Hilbert transform of the intrinsic mode function(IMF) using the HHT analysis gives the Hilbert energy distribution spectrum in the time and frequency domains and the time amplitude spectrum after the IMF function reconstruction. These can be used to analyze vibration data from a liquid oxygen turbopump in the time and frequency domains to diagnose turbopump faults. This method is very useful for test data analyses and fault location in rocket engines and other complex assemblies.