Molecular Dynamics Simulation of Stationary and Rotating Nanotube in Uniform Liquid Argon Flow

Abstract

In this paper molecular dynamics (MD) simulation is used to investigate the liquid argon flow past a stationary and rotating carbon nanotube. The main purpose of this work is to estimate flow forces on the nanotube and compare them with classical continuum results. The simulation is 3D and consists of 33,700 liquid argon atoms as fluid and 240 atoms of carbon as the nanotube. The single walled nanotube is simulated as a rigid cylinder of fixed carbon atoms. For simulation of rotating carbon nanotube, carbon atoms are rotated around center axes of the nanotube in each times step according to the desired angular velocity. Both argon-argon and carbon-argon interactions are modeled by Lennard-Jones potential function. Periodic boundary condition is used for the whole system. Flow is driven by rescaling velocities at the inlet each 50 time steps. The results show that the rotation of nanotube causes a reduction in drag force, up to rotation rate of 3.0 where the drag force is about 78% of the stationary one. Above the rotation rate of 3.0 drag coefficient is almost constant. Lift coefficient of stationary nanotube is negligible in comparison with drag coefficient and the rotation of nanotube has a little influence on the lift coefficient.