Theoretical study of a metasurface-based sound absorber

A metasurface-based sound absorber panel is proposed to achieve high sound absorption with a deep sub-wavelength thickness and a relatively broad bandwidth. The panel composed of different periodically-arranged Helmholtz resonators has been designed by a radiation impedance model which takes the mutual radiation impedance into account. Numerical simulations based on COMSOL Multiphysics show that the radiation impedance model yields more accurate results compared with the traditional equivalent surface impedance method. Broad bandwidth of sound absorption is achieved under proper coupling by carefully tuning the geometry and distance between Helmholtz resonators. A metasurface-based sound absorber panel is proposed to achieve high sound absorption with a deep sub-wavelength thickness and a relatively broad bandwidth. The panel composed of different periodically-arranged Helmholtz resonators has been designed by a radiation impedance model which takes the mutual radiation impedance into account. Numerical simulations based on COMSOL Multiphysics show that the radiation impedance model yields more accurate results compared with the traditional equivalent surface impedance method. Broad bandwidth of sound absorption is achieved under proper coupling by carefully tuning the geometry and distance between Helmholtz resonators.