Many processes in various industries involve the simultaneous flow of fluids and particles. Just to cite a few examples:
Slurry mills (mining industry)
Cyclones, desanders, and drill cutting removal (oil and gas industry)
Pneumatic conveyors (multiple industries)
Wastewater management (waste disposal industry)
Grains drying and sorting (agriculture and food industries)
Biomass reactors (energy industry)
Fluidized beds and catalytic reactors (chemical and nuclear industries)
In all these cases it is important to take the fluid flow into account in order to get the correct behavior of the particles. Design and scale-up, as well as optimization of such processes, require a deep understanding of the thermo-hydrodynamics, which is determined by the particle-level interactions between the fluids, particles, and boundaries. So it is clear that we need a modeling strategy to deal with granular-fluid systems.