Abstract:
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.