Study On Flow Characteristics Of Couette Flow At Microscale

With the advancement and development of nanotechnology,micro/nano electromechanical systems have been widely used in industrial,medical and physical research fields.However,the micro/nano electromechanical systems generally have unconventional flow phenomena,which will greatly limit the development of such systems.This topic uses Material Studio molecular dynamics simulation software to study the flow characteristics of Couette in microsystems,which is of great significance for solving microscale flow.First,this paper uses argon-based fluids to compare the effects of different densities,wall velocities,and wall materials on the flow in microchannels.The results show that The greater the density of the fluid,the more force a single fluid particle will receive and the less likely it is to move freely.However,due to the effect of wall attraction,the equivalent viscosity near the wall increases with the increase of density and the slip will decrease.However,due to the effect of wall attraction,the equivalent viscosity near the wall surface increases with the increase of density and the slip amount will decrease.When the wall materials are different,the metal wall surface has stronger force than the non-metal wall surface,so the equivalent viscosity near the metal wall surface is larger.As the wall speed increases,the equivalent viscosity near the wall will decrease,causing the fluid particles to not easily move along the wall.Secondly,the article calculates the Couette flow of the added particles and then analyzes whether the presence of the particles affects the movement of the argon fluid.The results show that both the particle size and the number of particles affect the micro-scale flow.If the particle size is larger or the number of particles is larger,the base fluid in the channel will not easily diffuse.When the particulate materials are different,the microfluidic,addition of the metal particles,is less diffusive.In addition,the paper studies the flow characteristics between different rough wall surfaces by molecular dynamics simulation.The results show that if the wall roughness is large,the fluid particle followability will be stronger and the slip amount will be reduced.