Acoustic propagation modeled by the curvilinear Fourier pseudospectral time-domain method

Abstract

The Fourier pseudospectral time-domain method is an efficient domain-discretization wave-based method to model sound propagation in inhomogeneous bounded media. The method was successfully applied to model atmospheric sound propagation and acoustics in urban environments. One of the limitations of the method is its restriction to a Cartesian grid, confining it to staircase-like geometries. When applying a transform from the Cartesian coordinate system to the curvilinear coordinate system, more arbitrary geometries may be solved by the method. In free field, the frequency dependent accuracy of the curvilinear Fourier pseudospectral time-domain method is investigated as a function of the deformation angle of the grid. Further, the performance of the curvilinear pseudospectral method is investigated for sound propagation in a box and for scattering from a rigid body. Finally, the sound field in a concert hall configuration with realistic boundary impedance values is computed. All computed results are in 2D and show good agreement against the boundary element method for low deformation angles.