Particle based simulation of fluid flow in periodically grooved channels

Abstract

The method of Dissipative Particle Dynamics is applied to investigate the effect of the parameters employed to model the presence of periodic rectangular wall roughness on planar nanochannel flow. The parameters considered here include the fluid/wall interactions, the range of interaction of fluid particles and wall particles (cut-off radius), the external applied force and the coarse-graining parameter (number of atoms per DPD particle). Protrusions of upper wall are modeled by periodically spaced rectangular protruding elements. The dependence of flow pattern on protrusion length and the amplitude of these parameters is investigated. The computed macroscopic quantities of practical interest include density, velocity, and pressure fields. Fluid particle localization near the solid wall is affected by the conservative force and the cut-off radius. Fluid velocity reduces as the protrusion length decreases for constant parameters and reduces as both the conservative force and the cutoff radius increases. The pressure is uniform across most of the channel and their pattern near and inside the cavities depend on the protrusion shape, the conservative force and cutoff radius. For the coarse graining parameter, the density and pressure remain almost constant in the core of the channel and their pattern near and inside the cavities depends on the protrusion shape.