THREE-DIMENSIONAL MOLECULAR DYNAMIC STUDY ON ACCOMMODATION COEFFICIENTS IN ROUGH NANOCHANNELS

摘要

To understand the wall effects in nanochannels, the accommodation coefficients for argon gas in platinum walls were calculated according to a proper statistical algorithm in three-dimensional MD method in isothermal flows and thermal conductions. In smooth channels, the wall lattice arrangement may induce atomic roughness on the surface so that the accommodation coefficients were different for different lattice configurations. While in nanochannels with hemispherical nanoscale rough cells, the roughness increased the possibility of multiple gas-wall interactions. The NMAC in rough channels was less than unity and decreased with larger roughness. Meanwhile, the TMAC in the isothermal flows and the EAC in the thermal conductions in rough channels were larger than those in smooth channels, and they both increased with larger roughness.