Effects of Shear Work on Non-Equilibrium Heat Transfer Characteristics of Rarefied Gas flow through Micro/Nanochannels

摘要

In the current work, the impact of shear work due to the slip velocity on non-equilibrium heat transfer in a pressure driven micro/nanochannel is evaluated under constant wall heat flux boundary condition. The DSMC method is employed as numerical tool. Implementation of the wall heat flux in the DSMC method is performed using the "modified Iterative" technique which in general eliminates any difficulty of implementation in adiabatic conditions and improves the solution convergence. We investigate the effects of rarefaction, property variations and compressibility. The numerical results show that shear stress on the walls significantly affects all aspects of the flow behavior and heat transfer through micro/nano channels such as heat flux rates. We also analyze the counter gradient heat flow phenomenon appearing at the cooling conditions. It is observed that viscous dissipation affects the heat flux applied to the walls and may overcome the wall heat flux, i.e., in the case of low cooling wall heat flux condition, shear work may completely heat the flow field.