管道管壁声压级传递损失测试方法

Transmission Loss Test of Duct Wall Sound Pressure Level

研究管道管壁的传递损失测试方法;管道内基于平面波分解入射波,利用双边界法消除管道内声源特性和 管道末端边界条件对测试结果的影响;空间测试为消声室环境,确保测试为自由场,管壁外无反射声,准确评价管壁自 身隔声特性;管道外分别用定点测量和声功率半球测点布置的方法进行测试。采用声强扫描声源识别,对不同材料的 汽车进气管道进行测试,与传递损失结果对比,表明传递损失结果可靠。测试结果表明相对于金属橡胶管道,塑料管 道在2000Hz到3000Hz隔声性能弱。

The test method of duct wall sound transmission loss is studied.In the duct,the incident waves are decomposed based on plan wave.The double boundary method is used to eliminate the effects of the internal sound source property and the boundary condition of the downstream pipe end,so that the natural acoustics property of the duct wall can be obtained.The special sound pressure is tested in an anechoic chamber to get the accurate sound insulation characteristics of the dust wall under the condition of free field without reflection effect.Outside the duct wall,the fixed measurement point method and the sound power semi-spherical measurement point layout method are used to test the sound insulation performance.Sound intensity mapping method is used to test the sound insulation performance of the duct wall for different type intake system.The results show that the transmission loss test method is reliable,can eliminate the test system effect and get the natural acoustic property of the duct wall accurately.The test results show that the sound insulation property of the plastics duct in the 2 000 Hz-3 000 Hz frequency range is weaker than that of the metal-rubber duct.