Investigating the Effect of Surface Roughness Size and Shape on the Nanofluid Behavior and Nanoparticles Aggregation in a Square Nanochannel by Molecular Dynamics Simulation

In this article, the effect of surface roughness size and shape on the Poiseuille flow of Ar–Cu nanofluid in a square copper nanochannel is investigated. To do this, hemispherical, cubic, semi-cylindrical roughness, shapes extended along the nanochannel length and width, and square protrusions extended along the nanochannel length and width are studied. The simulations are carried out using the molecular dynamics method and LAMMPS software. The results show that the roughness causes a change in the velocity and structure of nanofluid atoms in the nanochannel. For example, the hemispherical roughness with a height of 7.5Å causes 24