KINETIC-THEORY OF SLIGHTLY STRONG EVAPORATION AND CONDENSATION - HYDRODYNAMIC EQUATION AND SLIP BOUNDARY-CONDITION FOR FINITE REYNOLDS-NUMBER

The asymptotic behavior for small mean free path of steady flow of a gas in contact with its condensed phase of arbitrary shape is investigated on the basis of kinetic theory. The hydrodynamic equations for the macroscopic quantities, the velocity, temperature, and pressure, of the gas and their boundary conditions on the interface between the gas and its condensed phase are derived up to the order of the Knudsen number squared, together with the Knudsen-layer correction near the interface. In the analysis, the perturbations from a uniform equilibrium state are assumed to be small, but their nonlinear effects are taken into account correctly so that the results obtained can be applied when the Reynolds number of the system is finite. This is an extension of the corresponding linearized theory by the same authors, which is valid only for very small Reynolds number. © 1979, THE PHYSICAL SOCIETY OF JAPAN. All rights reserved.