Eulerian simulations of premixed submerged multiphase turbulent jet: RANS based approach

The recovery of mineral ores greatly depends on the hydrodynamics in a froth flotation process. Turbulent jets are created inside a froth flotation cell to enhance mixing, and thus improve recovery of mineral particles. Computational Fluid Dynamics (CFD) simulations provide a means to study such two- or three-phase turbulent jet flows by using mathematical models. The purpose of the current work is to validate the Euler-Euler CFD simulations in OpenFOAM using a set of interfacial closure models to predict the behavior of multiphase turbulent jet flows. Previously, simulations using this framework and validations were carried out for bubble columns by Rzehak and Kriebitzsch (2015) and for stirred tanks with solid-liquid flows by Shi and Rzehak (2020). The baseline closure models employed include drag, shear lift, virtual mass, wall forces, and turbulent dispersion forces for the gas-liquid as well as the solid-liquid interactions. In the present contribution, new CFD simulations using this framework are reported and validated with experimental results from Sun and Faeth (1986) for bubbly jets pointing in upward direction, and from Parthasarathy and Faeth (1987) for particulate jets pointing in downward direction. Along the axial and radial direction of the jet, a reasonable agreement is observed between the experimental and simulation results. Extending the scope of the topic, an attempt is made to simulate also three-phase premixed turbulent jets using the individually validated combination of closure models for both gas-liquid and solid-liquid jets jointly in the same simulations. Suitable data to validate the overall closure models for premixed gas-solid-liquid three-phase turbulent jet flows are not available in the literature. Thus, the simulations for three-phase turbulent jets are carried out in the same setup as used previously for the gas-liquid and the solid-liquid turbulent jets. A parametric study is carried out for the interfacial forces and an attempt to understand the interaction between the disperse and accompanying continuous phase will be presented.