CFD-DEM: Modeling the Small to Understand the Large

CFD-DEM is a powerful numerical method used to study multiphase particulate flows which couples a traditional computational fluid dynamics (CFD) approach for the fluid phase with the discrete element method (DEM) for the particles. This article provides a general overview of several key methods used for the numerical simulation of gas-solid multiphase flows and where CFD-DEM fits into the picture, describes the current state of the art of CFD-DEM with an emphasis on the main challenges and bottlenecks, and outlines areas for improvement aimed at addressing industrial needs.