AS350B2直升机飞行噪声的试验研究

中国航空研究院和德国宇航院合作开展直升机噪声研究,选择一架AS350B2直升机在哈尔滨平房机场进行了噪声测量。介绍了这次飞行试验的设备和试验方法,列出了全部十个试验飞行状态的暴露噪声级,并对试验直升机起飞爬升、水平飞行和下滑飞行时的噪声信号进行了频谱分析及小波分析。结果表明:试验直升机在起飞爬升和下滑飞行时的噪声水平较高,起飞爬升时噪声主要来自尾桨,下滑飞行时噪声主要来自旋翼的桨涡干扰,而且在直升机以中等飞行速度和大约6°的下滑角飞行时最为严重,并且桨涡干扰噪声指向前行桨叶一侧。

An experimental study of AS350B2 helicopter noise

In a cooperative research program of helicopter noise between Chinese Aeronautic Establishment and German Aerospace Center, one Aerospatiale AS350B2 helicopter was chosen to take noise measurement flight tests at Pinfan airport, Harbin, China. This paper presents the test design, instrumentation set-up and the test results for all of 10 operating conditions. Some of the test data are studied based on the Fourier transform and the wavelet transform. The experimental results show: (1) the high sound exposure lever appears in take-off and approach conditions, (2) the impulsive noise mainly originates from the tail rotor in take-off flights and from the main rotor in approaches, (3) when the helicopter flights at mid-speed and about 6° approaches, the serious blade vortex interaction happens and its noise directs towards the rotor advance sides.