Absorbing boundary conditions for second-order hyperbolic equations

摘要: Abstract A uniform approach to construct absorbing artificial boundary conditons for second-order linear hyperbolic equations is proposed. The nonlocal condition given by a pseudodifferential operator that annihilates travelling waves. It obtained through the dispersion relation of differential equation requiring initial-boundary value problem admits wave solutions in one direction only. Local approximations this global yield an nth-order operator. shown best must be canonical forms which can factorized into first-order operators. These conditions are perfectly packets propagating at certain group velocities. hierarchy derived transonic small perturbation unsteady flows. examples illustrate easy derive, and effectiveness demonstrated numerical experiments.