轴流压气机转子叶片非同步振动的声传播特征研究

Investigation into the Characteristics of Sound Propagation Corresponding to Non-Synchronous Vibration of Rotor Blades in an Axial Compressor

围绕某型涡扇发动机压气机内部噪声环境下转子叶片气固耦合振动失效问题,开展某型涡扇发动机压气机流道内部噪声测量试验,主要研究压气机高压一级转子叶片发生非同步振动(NSV)时压气机流道内部声波传播特征。针对压气机高压一级转子叶片发生NSV时,研究了6个测点位置处噪声信号特征,确定了噪声源位置以及特征频率噪声信号沿压气机周向和轴向位置的传播特性,并应用环形管道声传播基本理论,初步计算了压气机内部特征频率噪声信号的基本物理特性。分析结果表明:诱发高压一级转子叶片NSV的声信号应起源于高压一级转子叶片排位置处;该声信号沿轴向位置的传播方式为:从高压一级转子叶片排位置向两端传播;周向传播方式为:周向阶数为6的声模态与转子旋转方向相反的方向传播;压气机内部声共振是诱发转子叶片NSV的主要原因。研究的内容和结论,对分析航空发动机压气机转子叶片故障问题、提高压气机性能和工作稳定性具有重要的参考价值。

A certain type of turbofan engine compressor internal noise measurement testing is carried out,which is centered on vibration failures of gas structure coupling of rotor blades under noise environment inner the compressor in some turbofan engine.And the emphasis is focus on the characteristics of sound propagation corresponding to non-synchronous vibration(NSV)of rotor blades in an axial compressor.Aiming at the first stage rotor blades of the high-pressure compressor occurring NSV,the characteristics of noise at 6 measured positions had been studied,the position of the noise source and the propagation characteristic of the characteristic frequency noise signal along the circumferential and axial direction were determined.The basic physical properties of compressor internal characteristic frequency noise signal were calculated preliminary with the basic theory of annular duct acoustic structure.The analysis results show that:the noise signal inducing NSV of the first stage rotor blades of the high-pressure compressor should be derived from the position of the first stage rotor blade row,the transmission mode along the axial direction of this noise signal is:from the first stage rotor blade row to both ends,the transmission mode along the circumferential direction is:an acoustic mode of circumferential order 6 in the compressor rotates in the opposite direction to rotor rotation.Acoustic resonance occurred in the compressor annulus space is main reason inducing rotor blades NSV.The results obtained in this paper can contribute to analyze and solve the vibration failures of rotor blades of the compressor,and have important application value on improving the performance and stability of the compressor.