MFiX — The Complete Guide: Free Multiphase Flow Simulation for Fluidised Beds and Reactors

MFiX is a multiphase CFD suite from the National Energy Technology Laboratory (NETL) of the US Department of Energy. It was built for flows where solid particles and gas move together — fluidised beds, reactors, gasifiers and pneumatic conveying — and has been validated against a large body of published experiments.

MFiX

US Department of Energy — NETL

Multiphase flow simulation for fluidised beds and reactors, from the US DOE.

Get it from the vendor

What you get

Two-fluid model (TFM) — gas and particles as two interpenetrating continua; the most mature and fastest option at large scale.
DEM — tracks every particle and its collisions, with high fidelity and high computational cost.
CGP and PIC — particles grouped into parcels, trading accuracy against run time.
Chemical reactions — reacting flow such as combustion and gasification.
Graphical interface — MFiX-GUI for case set-up, running and monitoring, on Windows, Linux and macOS.

What to know

The software is free, but downloading from the NETL site requires registration. Choosing the model is the key decision: TFM for an industrial-size system, DEM for a detailed look at a small one. Multiphase runs are long, so start from the bundled examples.

Related tools

For general multiphase flow — OpenFOAM. For material and energy balances of the whole process — DWSIM. For reaction kinetics and thermodynamics — Cantera.