Narrow Results

This paper carries out numerical simulation for pressure driven microscale gas flows in transition flow regime. The relaxation time of LBM model was modified with the application of near wall effective mean free path combined with a combination of Bounce-back and Specular Reflection (BSR) boundary condition. The results in this paper are more close to those of DSCM and IP-DSCM compared with the results obtained by other LBM models. The calculation results show that in transition regime, with the increase of Knudsen number, the dimensionless slip velocity at the wall significantly increases, but the maximum linear deviation of nonlinear pressure distribution gradually decreases.

The current work investigated and analyzed the performance of conventional slip models among various regimes of Knudsen number, and developed a new slip velocity model, multi coefficient model, suitable especially to transition regime by using Taguchi quality control techniques and numerical analysis. In comparison with conventional slip models, the multi coefficient slip model has a better agreement with the solution obtained from the linearized Boltzmann equation and direct simulation of Monte Carlo method (DSMC) than the other models, especially in the regime of Knudsen number equal to or larger than one.