Three-dimensional acoustic characteristic study of porous metasurface

We propose a two-dimensional (2D) acoustic metasurface fabricated using porous material. An analytical model is developed to predict the three-dimensional sound field produced by an incident acoustic wave interacting with acoustic porous metasurface. The validity of analytical model is validated by comparing with numerical simulations. The directivities of reflected waves can be fully predicted by the analytical model, which overcomes the limitations imposed by using a model based on the three-dimensional generalized Snell's law. The proposed porous metasurface allows to provide quasi-omnidirectionally perfect sound absorption at the designated frequency and a fixed periodic length. Such porous metasurfaces also display better broadband sound absorption properties than that constructed by a homogeneously porous layer.