Ab initio simulation of rarefied flows of gaseous mixtures in the system of microbeams with different temperatures

Abstract

The issues of gas flows induced by inhomogeneous temperatures in a rarefied gas and exerting Knudsen force on the immersed structures are classic in the field of rarefied gas dynamics. The rarefied flows of HeNe gaseous mixtures in the system of microbeams with different temperatures for different combinations of equilibrium temperatures, rarefaction parameters, and mole fractions are studied using direct simulation Monte Carlo (DSMC) method in combination with ab initio (AI) potential with quantum scattering. Moreover, an extra simulation for VSS model is conducted by the same method to investigate the influence of inter-atomic potentials. The research results demonstrate that the rarefaction parameter for the maximum value of Knudsen force on the beams is related to the beam temperature. By comparing the results of AI and VSS potentials, it is found that the difference between the results predicted by the two potentials in the free-molecular regime is almost negligible. However, in transition regime or in an extremely low (or extremely high) temperature environment, the difference between the results is significant. In particular, in the transition regime with equilibrium temperature of 10 K, the maximum relative deviations of heat transfer coefficient and Knudsen force are 19.43% and 194.29%, respectively.