Applying boundary condition in dissipative particle dynamics using mirror-image particles

A computational technique for applying wall boundary condition in dissipative particle dynamics simulation is presented. Based on the method first suggested by Willemsen et al. [14], the technique uses mirror image particles to naturally and effectively enforce the no-slip and no-penetration conditions. The technique is applied to the internal flows of various cross sectional shapes. The most important factor that ensures accurate application of the boundary conditions turns out to be the ratio of the narrowest gap between the facing walls to the particle diameter. When the ratio is sufficiently large, geometric features such as curvature, variation of curvature, and sharp corners can be well represented by the technique using mirror image particle. Also, by calibrating the size and direction of the shift in positions of image particle, spurious density oscillation near the boundary can be reduced while the velocity boundary conditions are sufficiently satisfied.