Dynamics of a Polydisperse Vapor Mixture Taking into Account Crushing, Coagulation, Evaporation of Drops, and Condensation of Vapor

Abstract

A numeric model of a hydro- and thermodynamics of polydisperse vapor–droplet mixture was constructed. It takes into account the processes of the crushing, coagulation, and evaporation of droplets and vapor condensation. The dynamics of the carrier medium is described by a set of motion equations for a viscous, compressible, heat-conducting gas that takes into account the mass, impulse, and energy exchange with fractions of disperse phase. Each disperse fraction of droplets is described by a set of equations including the continuity equation for the average density, the equation for the conservation of impulse components, and the heat energy conservation equation. These take into account the interphase mass, impulse, and energy exchange with the carrier medium. Numerical solution of the equation set for motion of the carrier medium and fractions of disperse phase by the explicit McCormack method with splitting of the spatial operator by directions and with the scheme of nonlinear correction at each time step represents the main part of the computation algorithm, which is supplemented by models of the crushing, coagulation, and evaporation of droplets and vapor condensation with further correction of the hydro- and thermodynamic parameters of mixture. A software package was developed based on the presented model, and an example of the computation of polydisperse vapor–droplet mixture flow with the coagulation, crushing, and evaporation of droplets and vapor condensation in a channel composed of coaxial cylinders was shown.