The Characteristics Of Flow And Condensation Of The Fluid In Microchannel By Molecular Dynamics Simulation

With the development of precise processing technology and microelectronic technology, more and more devices of micro-electromechanical systems(MEMS) have appeared. Because of the reduction of the size of devices, a lot of microstructures have been formed, and the physical properties of fluids in these microstructures have a large influence on the performance of the corresponding devices.This thesis is focuses on the fluid in these microstructures. Based on the statistic thermodynamics theories, we adopt molecule dynamics simulation(MDS) and Lennard-Jones (L-J) potential function to investigate the flow and condensation process of fluids in the microstructures. Meanwhile, this paper also carries on research to the condensation process on the corrugated plate is simulated for water-vapor. The main content are as following:1 Established the models of fluid flowing through a parallel microchannel and condensed in it on the condition of periodic external force, respectively.2 Based on the established models, the flow characteristics of argon fluid were investigated when passing through the hydrophilic walls and hydrophobic walls, respectively. At the same time, water passing through the hydrophilic wall with different densities at 300℃was also studied.3 The flow pattern during the process of water-vapor condensation was simulated by molecular dynamics simulation for the first time, and the influencing factors were also analyzed when one pattern changes to another one.4 The condensation process on the corrugated plate and flat plate for the water-vapor from 300℃to 20℃was simulated, respectively, and compared the differences between them.5 Compared the characteristics of hydrophilic walls with that of hydrophobic walls from the trajectories of single particle near the walls, heat transfer performance and the pressure variation.