薄膜型声学超材料的管道消声特性研究

针对管道低频流噪声难于有效控制的弊端,设计了一种薄膜型声学超材料及其性能测试装置,根据声波传递理论计算了管道内薄膜在声压作用下的振动特性。利用COMSOL软件的声固耦合模块研究了薄膜的消声特性,并进行了对比试验。结果表明:薄膜在低频范围内有较好的消声性能,薄膜的共振频率即为其消声工作频率;薄膜的振幅越大,传递损失值越高,最高达54 dB;薄膜参数的变化对超材料的消声性能有调节作用,通过改变施加在薄膜上的预应力和薄膜厚度,分别实现了传递损失峰值频率偏移120 Hz与110 Hz;通过改变附着质量块大小,实现了100 Hz及以下超低频消声。相关研究为主动声学超材料以及紧凑型管道消声器的设计提供了依据。

esearch on the pipeline silencing characteristics of membrane-type acoustic metamaterial

For pipeline low-frequency flow noise is difficult to control, a kind of membrane-type acoustic metamaterial and its performance test device are designed. According to the sound wave transfer theory, the vibration characteristic of the membrane under the sound pressure of the pipeline is calculated, and the silencing characteristics is simulated by using COMSOL sound-solid coupling module, and comparative experiments are carried out. Research revealed that:the membrane has a good performance in low frequency range and the silencing performance of membrane is strongly related to its resonant frequency, and the resonant frequency of the membrane is its silencing frequency. The larger the amplitude of the membrane, the greater the transmission loss of the device, and the highest noise elimination is up to 54 dB. The parameter variation plays an important regulatory role in the silencing performance. The offsets of the peak frequency of the device are 120 Hz and 110 Hz respectively by changing the prestress on membrane and the membrane thickness; the attached mass block realizes the ultra-low frequency noise elimination at 100 Hz and below. The related research provides a basis for the design of active acoustic metamaterial and compact pipeline muffler.