Fluid–solid boundary conditions for multiparticle collision dynamics

Abstract

The simulation of colloidal particles suspended in solvent requires an accuraterepresentation of the interactions between the colloids and the solvent molecules. Using themultiparticle collision dynamics method, we examine several proposals for stick boundaryconditions, studying their properties in both plane Poiseuille flow (where fluid interactswith the boundary of a stationary macroscopic solid) and particle-based colloid simulations(where the boundaries are thermally affected and in motion). In addition, our simulationscompare various collision rules designed to remove spurious slip near solid surfaces, and theeffects of these rules on the thermal motion of colloidal particles. Furthermore, wedemonstrate that stochastic reflection of the fluid at solid boundaries fails to faithfullyrepresent stick boundary conditions, and conclude that bounce-back conditions should beapplied at both mobile and stationary surfaces. Finally, we generalize these ideas tocreate partial slip boundary conditions at both stationary and mobile surfaces.