A Hybrid Method for Simulating Flows Including Fluid Particles

A hybrid CMFD (computational multi-fluid dynamics) method is proposed for the prediction of multiphase flows including large-scale interface, poly-dispersed bubbles and/or 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 (1) to cover a wide range of d* = d/Δx, where d is the particle diameter and Δx the grid size, and (2) to perform various kinds of multiphase CFD such as standard interface tracking, particle tracking and multi-fluid simulations, and hybrid simulations using an arbitrary combination of ITM, PTM and MFM. The field and constitutive equations of the proposed method are described in detail. A poly-dispersed air-water bubbly flow and several bubble plumes in a small open vessel are simulated using the proposed hybrid method to demonstrate its potential.