Numerical investigation of rarefied diatomic gas flow and heat transfer in a microchannel using DSMC with uniform heat flux boundary condition - Part I: Numerical method and validation

摘要

For flows associated with microelectromechanical systems (MEMS), the heat flux specified (HFS) boundary condition exists broadly. However, problems with the HFS boundary condition have not been well realized in the simulations of microchannel flows using the direct-simulation Monte Carlo (DSMC) method. In the present work, inverse temperature sampling (ITS) is used to deal with diatomic gaseous flow and heat transfer in a microchannel. This technique provides an approach to calculate the molecular reflective characteristic temperature from the molecular incident energy and the heat flux at the wall boundary. Coupled with the DSMC method, this diatomic molecule ITS technique can be used to treat the HFS boundary conditions in the DSMC method. Verification indicates that the proposed diatomic molecule ITS method can accurately simulate the gaseous flow and heat transfer. In Part II of this work, the proposed method is applied to demonstrate general microchannel gaseous flow properties under uniform heat flux boundary conditions. at the same time, the new method is adopted to numerically investigate the effects of wall heat flux on gaseous flow and heat transfer properties.