Chapter 7: Multiphase Flow Modeling

Multiphase flow refers to the situation where more than one fluid is present. Each fluid may possess its own flow field, or all fluids may share a common flow field. Unlike multicomponent flow, the fluids are not mixed on a microscopic scale in multiphase flow. Rather, they are mixed on a macroscopic scale, with a discernible interface between the fluids. Ansys CFX includes a variety of multiphase models to enable the simulation of multiple fluid streams, bubbles, droplets, solid particles, and free surface flows.

Two distinct multiphase flow models are available in Ansys CFX, an Eulerian-Eulerian multiphase model and a Lagrangian Particle Tracking multiphase model. Information on the use of the Lagrangian Particle Tracking model is available in Particle Transport Modeling.

This chapter describes how Eulerian-Eulerian multiphase flow is modeled and also includes modeling advice. The theory of multiphase flow is available; see Multiphase Flow Theory in the CFX-Solver Theory Guide.

The corresponding information for single-phase, single-component flow is available:

For information on the models used for single-phase flow, see Basic Capabilities Modeling.
For the mathematical implementation of the single-phase flow, see Basic Solver Capability Theory in the CFX-Solver Theory Guide.
For advice on modeling, see Advice on Flow Modeling.

Important: Because this chapter extends the information given in the single-phase documentation, you are advised to read the relevant sections in the single-phase documentation before reading this chapter.