A study on ultra-thin and ultra-broadband acoustic performance of micro-perforated plate coupled with coiled-up space structure

Abstract

The sound wave of low-frequency noise has strong penetration, consumes less energy in the propagation process, and is not easy to be consumed by traditional materials. In order to solve this problem, the micro-perforated plate (MPP) coupling a coiled-up space structure (MPCS) has been proposed. The MPCS is composed of an MPP and a coiled-up space structure, and its overall thickness is only 30 mm. The finite element method (FEM) and theoretical calculation were used to predict the sound absorption performance of a single MPCS. Results show that this structure is 100 % effective at absorbing sound at the resonance frequency. Moreover, the effects of the perforation ratio, aperture, and cavity length L of the MPCS have been studied in this paper. We constructed a sound-absorbing unit (MPCSs) consisting of three coiled-up space channels and six micro-perforated plates, then a broadband sound absorbing body (Bi-MPCSs) was constructed, which has two absorbing units with different parameters in parallel. Its sound absorption achievable reached more than 50 % in the range of 415 Hz–905 Hz, and the average sound absorption was more than 75.6 %. Next, the theoretical calculation results verify the accuracy of the simulation results. To further broaden the sound absorption performance of Bi-MPCS, a low-frequency and ultra-wide frequency sound absorption body (F-MPCSs) composed of four different parameters absorbing units (MPCSs) were constructed. Interestingly, the sound absorption of the absorber achieved more than 50 % in the range of 350 Hz–1150 Hz, and an average sound absorption reached 66.7 %.