Wave propagation and reflection in irregular grids for hyperbolic equations

Attention is given to numerical wave propagation in a nonuniform grid on which difference approximations to hyperbolic equations have been established. The standard mathematics of linear wave propagation in inhomogeneous media is introduced, and basic relations are derived that apply to the propagation and internal reflection of spurious solutions in the corresponding computing domains. It is shown that, if the approximation scheme is nondissipative, those spurious solutions may remain trapped in the computing domain, preventing the steady state from ever being reached. (B.J.)