Numerical Simulation Analysis Based On Ansys Software For Gaseous Flow In Micro-Channel

The micro-electromechanical systems became popular from the late20th century and are developing rapidly in the early21th century. The micro-channels that are composed of micro-electromechanical systems are necessary, which bind the components in microfluidic systems. With the research and development of MEMS, the feature size of micro-device and micro-channel became further smaller; therefore, the field of gaseous microflow exists, because the classic macroscopic hydrodynamic model is no longer applicable to the analysis of the gaseous flow in the micro-channel. Gaseous flow in micro-channel is unique compared with the macroscopic flow, so the research on gaseous flow in the micro-channel is a key factor in promoting the further development of MEMS technology.This article shows the analysis based on the famous fluid analysis software ANSYS Fluent, which established the gaseous flow model based on the theory of gaseous flow in micro-channel and did some numerical simulation analyses on the gaseous flow in micro-channel under the different pressure-driven and shear-driven flow to get the pictures of outlet velocity distribution and mass flow rate at different Knudsen number. Simultaneity, analyze and compare the similarities and differences of the gaseous flow characteristics in micro-channel with the macroscale problem, compare the theoretical results with the simulation results and investigate the phenomenon of rarefaction effect.The simulation results verified that there is a great change on the flow characteristics of the fluid in the micro-channel and the classical foundation continuum assumption becomes invalid. Therefore, the macro-scale classic continuum theory needs to be amended in microfluidics.The simulation results also showed that when the feature size was further reduced, the rarefaction effect, the slip velocity and the mass flow rate became larger. However, the size of channel is not the only factor. Due to the small-scale or small working pressure in micro system, gaseous flow has a large Knudsen number, which has a significant rarefied gas effect. In the micro-channel, there is a distinct macroscopic scale phenomenon that the greater Knudsen number, the greater the slip velocity and mass flow rate.