Boundary conditions for gases on a body surface

Computation of rarefied diatomic gas flows through a plane microchannel

“…The boundary conditions from [6,7] are set on the channel surface at y = 1. The distribution function of reflected particles has the form…”

“…For the fully diffuse interaction, the flow rate through the channel for a diatomic gas is close to that for a monatomic gas. However, when a diatomic gas flow is com puted with the boundary conditions of [6,7], which take into account the physics of the interaction between diatomic molecules and the solid surface, the flow rates for diatomic and monatomic gases differ.…”

“…The difference is that the rotational energy of a diatomic gas molecule inter acting with the wall can convert into translational energy. In [6,7] this effect was examined and taken into account in boundary conditions. In this study, diatomic (nitrogen) gas flows were computed with bound ary conditions other than those in [6,7] and with the fully diffuse interaction, when the temperature of the reflected particles is equal to that of the wall.…”

“…In [6,7] this effect was examined and taken into account in boundary conditions. In this study, diatomic (nitrogen) gas flows were computed with bound ary conditions other than those in [6,7] and with the fully diffuse interaction, when the temperature of the reflected particles is equal to that of the wall. For the fully diffuse interaction, the flow rate through the channel for a diatomic gas is close to that for a monatomic gas.…”

“…A near wall The computations performed have shown that the new boundary condition (1.12), (1.7) should be used in the description of diatomic gas flows. For a heat transfer problem, the effectiveness of boundary condi tion (1.12), (1.7) for describing the interaction of a diatomic gas with the body surface was demonstrated in [6,7] by comparing numerical results with experimental data.…”