Abstract

Molecular dynamics simulations were employed to investigate Ar flow through a Cu nanochannel and the transport of Cu nanoparticles (NPs) of varying cylindrical sizes under different inlet velocities. The results revealed laminar flow with velocity and density profiles consistent with classical Poiseuille flow, confirming the validity of continuum assumptions for the nanoscale lengths considered here. Layers of solid-like structure were formed near the channel walls, and the apparent viscosity of the Ar fluid flow was found within expected values. The presence of NPs influenced the local flow behavior. NPs traveled faster than the average fluid velocity when moving near the channel center. Additionally, smaller NPs exhibited translational and rotational fluctuations due to lower inertia and stronger coupling with the fluid flow, whereas larger NPs moved more stably, dominated by inertial effects. Interfacial analysis showed that Ar atoms formed ordered layers on the NP surfaces, with coordination increasing with NP size. Higher inlet velocities disrupted these layers, reducing structural ordering. These findings provide atomistic insight into the interplay between hydrodynamics, NP size, and interfacial structuring, enhancing the understanding of NP transport and fluid-solid interactions in nanoscale channels.