The Modeling of Lift and Dispersion Forces in Two-Fluid Model Simulations of a Bubbly Jet

Abstract

Two-fluid model simulations of a bubbly vertical jet are presented. The purpose of these simulations is to assess the modeling of lift and turbulent dispersion forces in a free shear flow. The turbulent dispersion models used herein are based on the application of a kinetic transport equation, similar to Boltzmann’s equation, to obtain the turbulent diffusion force for the dispersed phase [1–4]. They have already been constituted and validated for the case of particles in homogeneous turbulence and jets [5] and for microscopic bubbles in grid generated turbulence and mixing layers [6,7]. It was found that it is possible to simulate the experimental data of Sun [8] (see Figs. 1–6) for a bubbly jet with 1 mm diameter bubbles. Good agreement is obtained using the model of Brucato et al. [9] for the modulation of the drag force by the liquid phase turbulence and a constant lift coefficient, CL. However, little sensitivity is observed to the value of the lift coefficient in the range 0<CL<0.29.