Eulerian-Eulerian two-fluid model for turbulent gas-liquid bubbly flows

摘要

The Eulerian-Eulerian two-fluid model presented in this paper emphasizes two aspects of the dynamic interactions between phases. First, the turbulent correlations associated with the added mass force are taken into account in the expression of the force exerted by the liquid on the bubbles, thus proving that the turbulent contributions of the interfacial transfer are significant in the phase distribution phenomena. Second, a turbulence model adapted to bubbly flows is developed. In this model, the Reynolds stress tensor of the continuous phase is split into two parts, a turbulent dissipative part produced by the gradient of mean velocity and by the wakes of the bubbles and a pseudo-turbulent non-dissipative part induced by the displacements of the bubbles: each part is predetermined by a transport equation. The application of the model to the simulation of three basic bubbly flows (grid, uniform shear and bubbly wake) confirms the pertinence of the improvements proposed for the closures of turbulence and of interfacial transfer. Comparison of the numerical results with the experimental data shows a good prediction of the mean and fluctuating velocities and of the phase distributions.