METHOD AND APPARATUS FOR CONSTRUCTING AND USING ABSORBING BOUNDARY CONDITIONS IN NUMBERICAL COMPUTATIONS OF PHYSICAL APPLICATIONS

摘要

A gradient method (GM) for constructing and using absorbing boundary conditions (ABCs) for high accuracy numerical computations of various physical phenomena which are governed by partial differential equations (PDEs) is disclosed. The PDEs to which the GM is applicable are for example: the Helmholtz equation (also known as the wave equation in the frequency domain), the elastic wave equation in the frequency domain, Maxwell's equations, and Schrodinger's equation. The GM can be used to develop ABCs for the solution of PDE problems in two or more dimensions. The GM is a tool based on two principles: (1) Any directional derivatives in an ABC must be taken in the direction of the gradient of the unknown function or functions of the PDE, and (2) any ABC using such gradient derivatives may be applied to any domain of a convex shape, even if the ABC was originally developed for domains of a restricted shape.