飞越适航噪声时域信号预测方法研究

以往对发动机有效感觉噪声级的预测研究是通过1/3倍频程谱进行计算,从而得到发动机地面预测有效感觉噪声级,而使用时域噪声数据进行发动机有效感觉噪声级预测的研究相对较少。研究了飞机起飞飞越过程中的噪声传播特性的计算方法,使用该方法来模拟计算飞机一台发动机在起飞飞越过程中地面飞越噪声测量点接收到的时域噪声信号数据。根据ANP数据库数据计算飞机起飞飞越航迹,使用声线法计算使用某时刻噪声声压信号传递的路程和时间,根据飞机速度方向与飞越地面噪声测量点的角度来确定该时刻噪声信号的最大声压值,最后得出飞机发动机在起飞飞越过程中部分时间内地面噪声测量点接受的时域信号数据,对飞机噪声适航审定提供一定的理论依据。

Research on signal prediction method of fly-over airworthiness noise in time domain

In the past, the prediction of the effective perceived engine noise level is calculated by one-third octave spectrum, and there are relatively few studies of using the engine noise data in time-domain to do so. This paper studies the method of calculating the noise propagation characteristics during the aircraft take-off and fly-over. The method is used to simulate the engine noise data in time-domain, which are received at the ground fly-over noise measurement point during aircraft take-off and fly-over. The flight path of the aircraft during take-off and fly-over is calculated according to ANP database data. And the sound ray method is used to calculate the travel distance and time of the noise signal at a certain moment. The maximum sound pressure value of the noise signal at this moment is determined according to the angle between the aircraft engine axis (i.e. the aircraft velocity direction) and the ground noise measurement point. Finally, the time-domain engine noise data in part time of aircraft take-off and fly-over are obtained at the ground noise measurement point, which provides a theoretical basis for airworthiness validation of aircraft noise.