A boundary condition for significantly reducing boundary reflections with a Lagrangian mesh

Reflections from the terminating mesh boundaries are an important consideration in the selection of the calculational grid size for the numerical solution of hyperbolic equations. An adjusted damper system along the boundaries is the technique for significantly reducing the boundary reflections which are discussed here. Fixed, scattering, and damped boundary conditions are compared for a two-dimensional calculation of an elastic material subjected to a sinusoidally varying pressure. The damping condition resulted in reflections which were about 11 percent of the amplitude of the reflection from a fixed or free boundary, and about 33 percent of that from a scattering boundary. 4 figures. (RWR)