A Study on Slip Characteristics Using Hybrid Particle-Continuum Method

Abstract

An effective boundary potential has been proposed to solve nonperiodic boundary condition (NPBC) of hybrid method. The optimized hybrid method is applied to investigate the influences of the channel height and solid–liquid interaction parameters on slip characteristics of Couette flows in micro/nanochannels. By changing the channel height, we find that the relative slip lengths show the obvious negative correlation with the channel height and fewer density oscillations are generated near the solid wall in the larger channel height. Moreover, we continue to investigate the solid–liquid interaction parameters, including the solid–liquid energy scales ratio (C1) and solid–liquid length scales ratio (C2). The results show that the solid–liquid surface changes from hydrophobic to hydrophilic with the increase of C1, the arrangement of liquid particles adjacent to the solid particles is more disorganized over the hydrophobic solid–liquid surface compared with the hydrophilic surface, and the probability of the liquid particles that appear near the solid particles becomes smaller. Meanwhile, the relative slip lengths are minimum when the liquid and solid particles have the same diameter. Furthermore, the relative slip lengths follow a linear relationship with the shear rate when the solid–liquid interaction parameters change. The plenty computational time has been saved by the present hybrid method compared with the full molecular dynamics simulation (FMD) in this paper.

Multiscale simulation of fluids: coupling molecular and continuum

“…Applying coupled simulations using complex molecules for tribology applications has been discussed in Fernandez,177 while the consideration of developing slip models from coupling was given in Yang et al 178 A variety of different materials with varying textures linked to varying interaction with fluids is considered in Yousefi-Nasab et al 55 Heat transfer was the focus of recent coupling work, 179 while a specific application with LAMMPS and OpenFOAM is presented in Cosden and Lukes. 21 The early work of Nie et al 58 also explored Couette flow and built in a post to induce a flow in the wall-normal direction.…”

“…This use of coupling avoids the need for wall models and they show the slip measures agrees very well with previous pure MD simulations. Applying coupled simulations using complex molecules for tribology applications has been discussed in Fernandez 167 , while the consideration of developing slip models from coupling was given in Yang et al 168 A variety of different materials with varying textures linked to varying interaction with fluids is considered in Yousefi-Nasab et al 55 Heat transfer was the focus of recent coupling work, 169 while a specific application with LAMMPS and OpenFOAM is presented in Cosden and Lukes 21 .…”

Study on the Contamination Characteristics of V-Type Double Suspension Rod Insulators Based on the Influence of Wake Flow

“…In their research, driven by the electric field force, the movement path of charged haze particles would deflect along the electric field lines, which would accelerate the precipitation of haze particles on the DC insulators. Yang Jiaxin et al [24] used the characteristic particle tracking method to calculate the contamination accumulation of insulators. The study shows that the surface area of an insulator is determined by the electric field strength, wind speed and other factors.…”