Application of the kinetic and continuum Techniques to the multi-scale flows in MEMS Devices

In our recent work, we have undertaken limiting 3D cases in order to understand the range of flows in present MEMS propulsion devices. The considered two cases are similar except for the plenum stagnation pressures and temperatures as well as modest differences in the geometrical configurations. Navier Stokes solutions were obtained for both cases while Direct Simulation Monte Carlo (DSMC) approach was utilized to model a low pressure case. Since the influence of the boundary layer on the flow characteristics is significant for the low Reynolds number cases, a special effort was made to predict the boundary layer structure as accurately as possible. To access the future development of a hybrid method, inviscid solutions were obtained and compared with an Euler solver and with an inviscid form of DSMC. In addition, different types of the boundary conditions were applied during the flow investigations in order to understand their influence on the flow structure.