微穿孔板消声器在MA60飞机APU排气管的应用

对MA60飞机APU排气噪声进行了测量,从测量结果可以看出,无论APU作在哪种工作状态,排气噪声均属于宽频噪声,主要是1000Hz以上的高频噪声,而满负载状态下的排气噪声除了高频含量之外,在400～1000Hz范围内也有较强的噪声。为了降低APU的排气噪声并结合APU具体的安装限制,选择了微穿孔板消声器来降低APU的排气噪声。通过试验比较,表明采用微穿孔板消声器降低MA60飞机APU排气噪声的效果是非常理想的。 

Application of Microporous to Reducing Exhaust Noise of APU on MA60 Aircraft

The exhaust noise radiation of APU (Auxiliary Power Unit) on MA60 aircraft is serious. Effective sound treatment technology should be employed to control the exhaust noise. The measured spectrum of APU exhaust noise shows that typical exhaust noise spectrum is very broad. Two general regions can be distinguished. A broad hump of low frequency random noise centering in the 400-1000 Hz region normally is present, which often is substantially stronger when fully loaded. A second broad hump of high frequency random noise centers in speech interference region of 1000-5000 Hz,which is the frequency range of the ear's greatest acuity. Considering the measured spectrum and APU equipment,a microporous muffler is used for reducting of APU exhaust noise. The measured results show that the effect of microporous muffler for noise reduction of APU exhaust is very satisfactory.