Contribution
Wave-Based acoustic Optimization of a Rectangular Plate Absorber Without Air-Tight Volume: Exploring the Dominant Damping Effects for Room Acoustics
* Presenting author
Abstract:
This study presents investigations into the acoustic behavior of a panel absorber without air-tight volume (PAWAV), focusing on its sound absorption capabilities concerning room acoustics, particularly at low frequencies. Traditional porous absorbers are limited in their effectiveness below 200 Hz, and plate absorbers typically exhibit narrowband resonances in this frequency range. To address these limitations, PAWAV systems, in which the plate is directly coupled to a porous material without featuring an air-tight volume, are analyzed for their ability to enhance low-frequency absorption. Finite Element Method (FEM) simulations are conducted to evaluate the interaction between the vibrating plate and the porous medium. The study expresses that this coupling behaves similarly to a spring-mass system, with primary absorption occurring within the porous material. Furthermore, diffracted sound waves at the plates edges penetrate the absorber laterally, contributing to its overall absorption. Three optimized absorber designs suggest that broad absorption ranges between 35 and 200 Hz can be achieved. A market analysis indicates that the optimized designs exhibit comparable effectiveness while having larger physical dimensions and a reduced surface weight. The conclusion proposes that while the PAWAV system exhibits broadband absorption of low frequencies, further improvements in design could enhance its performance.