Comparison of Numerical Models of the Dynamics of Electrically Charged Gas Suspensions with Mass and Surface Charge Densities for Different Particles Dispersities

Abstract

The purpose of the study was to mathematically model the dynamics of inhomogeneous electrically charged media, such as that of gas suspensions, i.e., solid particles suspended in a gas. The mathematical model implemented a continuum approach to modeling the dynamics of inhomogeneous media, which implies taking into account intercomponent heat transfer and momentum exchange. The carrier medium was described as a viscous, compressible, heat-conducting gas, the equations of the model were supplemented with initial and boundary conditions, and the system of the equations was integrated by an explicit finite-difference method. To obtain a monotonic grid function, a nonlinear scheme for correcting the numerical solution was used. The mathematical model was supplemented with the Poisson equation describing the electric field, which is formed by electrically charged disperse inclusions. The Poisson equation was integrated by finite-difference methods on a gas-dynamic grid. The flow of a gas suspension caused by the motion of dispersed particles under the action of the Coulomb force was studied numerically. Flows of gas suspensions with surface and mass densities of electric charge were modeled. For the surface charge density model, the Coulomb force acting on the unit mass of the gas suspension increases with a decrease in the dispersion of particles. For the mass charge density, the dispersion of particles does not affect the specific Coulomb force acting on the particles. The intensity of the gas suspension flow increases with decreasing particle size, both for the mass and surface models of charge density. For the surface charge density model, as the particle size decreases, the intensity of the gas pressure drop in the emerging gas suspension flow increases more than when modeling the gas suspension dynamics with a mass distribution of the electric charge density