Study on the scattered sound modulation with a programmable chessboard device

Abstract

Metasurfaces open up unprecedented potential for applications in acoustic deflection. Achieving adaptive control of a scattered sound field (SSF) using a flexible metasurface structure is of great scientific interest. However, as the conventional finite element method (FEM) is limited by computational efficiency, it is necessary to develop a fast and accurate method to predict the SSF. In this work, we design a chessboard device with an array of square grooves for the modulation of SSF and develop a fast calculation method for 3D SSF using a Kirchhoff approximation phase correction. Several SSF spatial modulations obtained using the chessboard model are computed with a fast algorithm. In addition, an experimental test-case in a semi-anechoic chamber, contrasted and analyzed scattered acoustic pressure using FEM, is designed to regulate the SSF performance of the chessboard device. Field measurements obtained show that the spatial directivity of chessboard device can be modified by artificially programming the phase or depth distribution of the groove array. The chessboard device and associated fast calculation method lend themselves to applications in the acoustic stealth of targets in air or water.