Simulation of Flow in Continuum-Transition Regime in Stepped-Microchannels Using Burnett Equations

In present study, the Navier-Stokes equations and the Burnett equations with Maxwell-Smoluchowski slip conditions for some values of Knudsen number are used to resolve the viscous compressible fluid flow of air in the stepped microchannel. An explicit finite difference scheme is employed to develop a two-dimensionl numerical Burnett solver for microfluidic flows and the second order stresses and heat fluxes in the Burnett equations are implemented into the code. Velocity slip/temperature jump conditions on the wall of the channel and on the step within duct are also used. Results are compared with those obtained by using the Navier-Stokes equations with and without the slip-wall conditions using flow in a microchannel. The effects of Knudsen number on the flow and the heat transfer characteristics of the microchannel are also investigated.