Study On Shear Flow Of Liquid Argon In Nanochannel With Molecular Dynamics Simulation

MEMS/NEMS are going through a high speed development contribute to the promotion of nano-technology. As an important application of NEMS, nanofluidic devices can be used in the manipulation and analysis of particles in nano-flow. Therefore, the research of flowing law in nano-scale is of great significance to the design and optimization of nanofluidic devices. Numerical simulation has its original excellence to deal with the nano-scale problems compared with experimental study and theoretical study. In this thesis, Molecular Dynamics (MD) method is used to simulate the Couette flow of liquid argon confined within a nano-scale channel. The number density distribution and velocity slip are determined through varying the wettability, temperature and shearing velocity. Meanwhile, resistance properties in nano-scale channel are investigated including the shearing force of wall, viscosity of liquid argon and friction coefficient.The results show that the number density of liquid argon presents a layered distribution of fluctuation. The temperature affects this distribution differently according to the different wettability. The shearing velocity of wall doesn't affect the number density of liquid argon in nano-scale channel. The velocity slip mainly depends on the number density distribution in the near wall region and it is more obvious with the decreasing number density of liquid argon. The shearing force of wall can be increased by the hydrophilicity enhancement, temperature decreasing and shearing velocity increasing. As the inherent attribute of flow, the viscosity of liquid argon isn't affected by the wettability and shearing velocity, however, it decreases with the increasing temperature which is the same as macroscopic liquid. In addition, The friction coefficient mainly depends on the number density distribution in the near wall region similar with the velocity slip.