Time-dependent acoustic scattering from generalized impedance boundary conditions via boundary elements and convolution quadrature

Abstract Generalized impedance boundary conditions are effective approximate that describe scattering of waves in situations where the wave interaction with material involves multiple scales. In particular, this includes materials a thin coating (with thickness as small scale) and strongly absorbing materials. For acoustic from generalized conditions, approach taken here first determines Dirichlet Neumann data system time-dependent integral equations usual operators, then scattered is obtained Kirchhoff representation. The discretized by elements space convolution quadrature time. well-posedness problem stability numerical discretization rely on coercivity Calderón operator for Helmholtz equation frequencies complex half-plane. Convergence optimal order natural norms proved full discretization. Numerical experiments illustrate behaviour proposed method.