Book excerpt: Multiphysics Modelling of Fluid-Particulate Systems provides an explanation of how to model fluid-particulate systems using Eulerian and Lagrangian methods. The computational cost and relative merits of the different methods are compared, with recommendations on where and how to apply them provided. The science underlying the fluid-particulate phenomena involves computational fluid dynamics (for liquids and gases), computational particle dynamics (solids), and mass and heat transfer. In order to simulate these systems, it is essential to model the interactions between phases and the fluids and particles themselves. This book details instructions for several numerical methods of dealing with this complex problem. This book is essential reading for researchers from all backgrounds interested in multiphase flows or fluid-solid modeling, as well as engineers working on related problems in chemical engineering, food science, process engineering, geophysics or metallurgical processing.