Development of a Unified Numerical Kinetic Approach, Taking into Account Many-Particle Interactions in Liquid-Vapor Systems

The study of evaporation and condensation should include consideration of heat and mass transfer processes inside the liquid, in the inter-phase transition domain, in the Knudsen layer, and in the outer area. Possible way to realize it is to use the conjugate approach, in which the description of these regions is carried out employing a single computational method. This method allows us to consider the condensed phase and gas as a single system and use the solution of kinetic equations throughout the region. Currently, processes in the gas phase have been studied quite well. The greatest obstacle to the use of kinetic equations in the condensed phase is the description of collisions involving multiple particles at the same time. In this paper a procedure is proposed to take the multi-particulate interactions within the condensed phase into account. Such approach is applied to the test study of the thermal conductivity problem for argon, neon, xenon, and krypton. Values of thermal conductivity coefficients for different quantities of interacting particles have been obtained. The comparison with corresponding experimental data is presented. Thus, the integral of paired collisions in the Boltzmann kinetic equation can be replaced by the proposed computational procedure. This approach provides a description of both liquid and gas at the level of the distribution function and ensures that the conditions at the interface are set correctly.