NUMERICAL SIMULATION OF AEROSOL OSCILLATIONS IN A CUBIC ACOUSTIC RESONATOR

This work is devoted to modeling aerosol oscillations in a cubic acoustic resonator, as well as in an acoustic resonator in the form of a tube, in which the height is an order of magnitude greater than the width. The mathematical model took into account the viscosity, compressibility and thermal conductivity of the carrier medium. For each of the phases of the mixture, gas and dispersed, a complete hydrodynamic system of equations was solved, including the equation of continuity of mass, spatial components of momentum and energy. Interfacial interaction included momentum exchange and heat transfer. The interphase momentum exchange took into account the force of aerodynamic drag, the dynamic force of Archimedes and the force of the added masses. The equations were integrated by a second-order accurate finite-difference method. A nonlinear correction scheme was used to suppress numerical oscillations. The equations of the mathematical model were supplemented with boundary conditions – for the components of the velocity of the carrier and dispersed phases of the mixture, homogeneous Dirichlet boundary conditions on fixed surfaces and homogeneous Neumann boundary conditions for the remaining physical parameters of the mixture were set. The change in the vertical component of the velocity was set on the moving surfaces. Numerical calculations of aerosol oscillations in the tube are compared with the results of a physical experiment; the comparison has shown acceptable results. The work revealed the regularities of the influence of the volumetric content on the dynamics of the mixture components. The calculation results demonstrate that the magnitude of the change in the pressure amplitude and velocity of the carrier medium and the velocity of the dispersed phase are inversely proportional to the volumetric content of the dispersed phase. The revealed regularity is explained by an increase in the interphase interaction with an increase in the concentration of the dispersed phase. Also, an increase in the volumetric content of aerosol leads to a decrease not only in the amplitude of oscillations, but also in the resonance frequency.

multiphase media, numerical simulation, Navier-Stokes equation, continual model, acoustic resonator, interphase interaction