Open Access

ARTICLE

Non-Equilibrium Molecular Dynamics Simulation of Water Flow around a Carbon Nanotube

by Wenzhong Tang¹, Suresh G. Advani¹

1 Department of Mechanical Engineering and Center for Composite materials, University of Delaware, Newark, DE 19716-3140, USA
2 Corresponding author; email: advani@udel.edu

Computer Modeling in Engineering & Sciences 2007, 22(1), 31-40. https://doi.org/10.3970/cmes.2007.022.031

Abstract

In this paper, non-equilibrium molecular dynamics (MD) simulations were performed to investigate water flow around a single-walled carbon nanotube. In the simulation, the nanotube was modeled as a rigid cylinder of carbon atoms. Water molecules were described with the extended simple point charge (SPC/E) model. The nanotube-water interactions were calculated with a Lennard-Jones potential between carbon-oxygen pairs. The water-water interactions comprised a Lennard-Jones potential between the oxygen-oxygen pairs and a Coulomb potential between all charge sites on interactive water molecules. It was shown that classical continuum mechanics does not hold when the drag forces on the nanotube are considered. In slow cross flows (perpendicular to the tube axis), the cross drag on a nanotube calculated from MD simulations were larger than those from the empirical equations, and the difference increased as the flow velocity decreased. It was also found that in axial flow (in longitudinal direction), due to severe slippage on the nanotube surface, the axial drag on a nanotube from MD simulation was very small compared with the calculation from continuum mechanics.

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Keywords

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