Study on effect of different surface roughness on nanofluid flow in nanochannel by using molecular dynamics simulation

Abstract

In this paper, the influence of surface roughness inside the nanochannel on nanofluid flowing properties was studied by using molecular dynamics simulation (MDS). In our simulations, water molecules were employed as the base fluid, and copper atoms were adopted to model the nanochannel walls and nanoparticles. In order to investigate the effect of surface roughness including rectangular, triangular, and hemispherical roughness on the flow properties of nanofluid, parameters such as temperature, total potential energy, velocity, and density profiles of H2O/Cu nanofluid were calculated. From the above simulation results, we find that increasing the roughness height increases the temperature and velocity of nanofluid. In addition, the surface roughness increases the velocity and temperature in the nanochannel by shrinking the cross-section with constant roughness height. And the surface roughness also reduces the range of fluctuations of the density near the walls in the nanochannel, which is because fewer fluid particles reside near the rough nanochannel walls compared to the ideal nanochannel. The other result is that the triangular roughness has the greatest effect on the flow properties of nanofluid, the effect of surface roughness on the flow property of nanofluid cannot be ignored.