Asymptotic boundary conditions for dissipative waves: general theory

Asymptotic Boundary Conditions for Dissipative Waves: General Theory

An outstanding issue in the computational analysis of time-dependent problems is the imposition of appropriate radiation boundary conditions at artificial boundaries. In this work we develop accurate conditions based on the asymptotic analysis of wave propagation over long ranges. Employing the method of steepest descent, we identify dominant wave groups and consider simple approximations to th...

Asymptotic preserving boundary conditions for kinetic models

Boundary conditions in dissipative particle dynamics

We study a continuum model for simulating solid boundaries of a DPD fluid. A layer of frozen DPD particles is placed on the wall boundary and a continuum limit is taken. This produces effective dissipative and random forces. In addition, a reflection at the wall must be specified in order to confine the fluid. Three different wall reflection laws are studied and their effectiveness in producing...

Asymptotic Solutions for Shells with General Boundary

The influence of arbitrary edge loads on the stresses and deformations of thin, elastic shells with general boundaries is studied by means of asymptotic expansions of a general tensor equation. Expansions are made in terms of an exponential or an Airy function and a series in powers of a small-thickness parameter. Most of the steps in the procedure are effected by using the dyadic form of the t...

Time-dependent and outflow boundary conditions for Dissipative Particle Dynamics

We propose a simple method to impose both no-slip boundary conditions at fluid-wall interfaces and at outflow boundaries in fully developed regions for Dissipative Particle Dynamics (DPD) fluid systems. The procedure to enforce the no-slip condition is based on a velocity-dependent shear force, which is a generalized force to represent the presence of the solid-wall particles and to maintain lo...