A Galerkin scheme for the time domain integral equation of acoustic scattering from a hard surface

The transient acoustic scattered wave from a hard surface is computed using a space‐time integral equation. A variational formulation of this integral equation is obtained from an energy identity, leading to a Galerkin‐type numerical procedure. By choosing an appropriate basis for the discretized functional space, this scheme is of the marching‐in‐time type with matrix coefficients. This technique is applied to a sphere, a box, and dihedron targets.