航空涡扇发动机喷气噪声分离技术

Study on Jet Noise Separation Technique of Turbofan Engines

涡扇发动机尾喷是飞机的主要噪声源之一,其噪声大小不仅影响飞机的适航取证,更是评价发动机性能的重要指标之一。为了实现发动机的降噪设计,需要将发动机的整机噪声分解到各部件,从而针对部件进行降噪设计。基于三个远场麦克风数据的喷气噪声分离算法,使用MATLAB进行编程,以GE公司的某型发动机噪声静态测试的数据作为输入数据,从发动机整机噪声中分离出喷气噪声,得到喷气噪声声压的自相关谱。根据喷气噪声声压的自相关谱,计算喷气噪声的声压级。分离得到的喷气噪声数据对发动机尾喷的降噪设计有重要意义。

Turbofan engine nozzle is one of the main sources of aircraft noise. The noise generated by the nozzle has a negative effect on airworthiness certification of aircrafts. It is also an important indicator of engine performance. In order to realize the noise reduction design of the engine, it is necessary to separate the noise of each component from the total engine noise to reduce its noise individually. In this paper, the jet noise separation method was proposed based on the engine noise data acquired by 3 far-field microphones. The program for this method was developed in MATLAB. With the use of the engine noise test data of the General Electric Company as the input data, the jet noise was separated from the total engine noise to obtain the self-correlation spectra of the jet noise sound pressure and calculate SPL of the jet noise. The jet noise data obtained by this method is important for the noise reduction design of engine nozzles.