多级轴流压气机内部噪声测试及频谱演化特征分析

Measurement and frequency spectrum characteristics analysis of the inner noise from a multi-stage axial compressor

主要研究压气机高压一级转子叶片出现非同步振动前后,压气机流道内部的噪声特性。利用声波导管系统,分别对某型涡扇发动机整机和压气机部件试验中压气机流道内部噪声进行了测量。对转子叶片振动前后噪声信号的频谱、特征频率处的声压级和总声压级的演化过程进行了详细分析,并与国外相关研究做了对比。分析结果表明:两种试验条件下压气机高压一级转子叶片出现非同步振动现象前后压气机流道内部噪声特性呈现相似的特征,进一步分析得知诱发压气机高压一级转子叶片非同步振动的声源可能仅存在于压气机局部范围内,激励可能是由气动力引起的并与旋转不稳定性有关。

This paper mainly investigates the characteristics of the noise in the compressor before and after the occurrence of non-synchronous vibrations （NSVs） to the first rotor blades of high pressure compressor. The noise in the compressor is measured on both a certain type of turbofan engine bench test and a high pressure compressor rig testing by acoustic waveguide system. A detailed analysis is conducted of spectrum, sound pressure level （SPL） of specific frequency and total SPL of the noise signal, which are then com- pared with the related studies abroad. The results show that noise characteristics in the two experiments share similar characteristics, from which can be inferred that the sound source inducing NSVs of the first rotor blades of high pressure compressor may only exist in the local area of the compressor and the vibrational ex-citation to the rotor blade may be aerodynamically caused and associated with a rotating flow instability in the compressor.