A Hybrid Method for Predicting Dispersed Gas-Liquid and Liquid-Liquid Multi-Phase Flows

Abstract

A hybrid CMFD (computational multi-fluid dynamics) method is proposed for the prediction of gas-liquid and/or liquid-liquid dispersed two-phase flows including large-scale interface, poly-dispersed bubbles and drops. The method is the hybrid integration of an interface tracking method (ITM), three kinds of particle tracking methods (PTM) and an averaging method based on a multi-fluid model (MFM). The integration enables us to cover a wide range of d*=d/Δx, where d is the particle diameter and Δx the grid size, and to perform various kinds of multiphase CFD such as standard interface tracking, particle tracking and multi-fluid simulations, and hybrid simulations by making an arbitrary combination of ITM, PTM and MFM. The field equations and numerical solution procedure of the proposed method are described in detail. To demonstrate its potential, a poly-dispersed air-water bubbly flow in a vertical square duct and an air-water bubble plume in an open vessel are computed using the combination of ITM, PTM and MFM.