Avaliação da distribuição e dinâmica de bolhas de ar em um tanque de flotação submetido a diferentes soluções utilizando CFD

Abstract

In the present graduation work, the objective was to evaluate the influence of different surface tensions, viscosities and densities in the process of formation of air bubbles in a flotation tank, using computational fluid dynamics (Computational Fluid Dynamics - CFD). The input data for the simulations, as well as the geometry of the simulated equipment, were based on data obtained experimentally. The simulations were conducted using the FLUENT® 19.3 software. To verify the proposed model, the simulated velocity and bubble diameter data were compared to the experimental results, both quantitatively and qualitatively. In addition to diameter and velocity data, the terminal velocity of the bubbles formed was analyzed, morphologically characterizing the air bubbles simulated according to Clift's Abacus. Through the CFD it was possible to infer the behavior and dynamics of the bubbles for the different conditions evaluated, with maximum deviations of 14.28% and 13.36%, respectively, between the bubble velocity and bubble diameter data obtained experimentally and by simulations. The simulated terminal velocity results were consistent with those obtained from theoretical models, with a maximum deviation of 19.05%. The analysis of the results indicated that the simulated bubbles present the ellipsoidal oblate shape. The mathematical model VOF (Volume of Fluid) was able to represent the experimental condition, even explaining the phenomenon of coalescence of air bubbles.