CFD Simulation including Particle Flow
Particle flows can be found in a plethora of industrial processes. From simple conveying (pneumatically, conveyors, batches) to complicated synthetic processes in the pharmaceutical industry and everything in between. Plastic particles are molded into car seat foam cushions, coffee beans get dried, ores are separated in wet cyclones and gas is dedusted in sifters. In order to optimize such processes using computer simulations, two distinct computational approaches need to be merged: DEM (Discrete Element Method) and CFD (Computational Fluid Dynamics). DEM deals with the interaction of large amount of particles (think: sand pile), while CFD describes the motion of fluids in a continuum. Since both methods are also computationally very intensive their coupling has only recently become feasible at all for computational simulation. Even so it takes a lot of experience to select from a number of available scientific models for each or the regimes (e.g. drag, momentum exchange, heat transfer, ...) and combine them in a sensible way.
Based on LAMMPS (Large-scale Atomic/Molecular Massively Parallel Simulator) a public library to model molecular dynamics an extension called LIGGGHTS® (LAMMPS improved for general granular and granular heat transfer simulations) was created and tied to the CFD part with CFDEM®. All these libraries are public and written to be used within the OpenFOAM framework. While these libraries are used by a number of people worldwide including a number of large industrial enterprises to optimize their machines and processes, they can be very difficult use. Additionally these methods are computationally very expensive limiting either the number of particles or the length of the simulation. Despite this it is possible to simulate millions of particles in granular flows. Without much further ado, below you see a video example of a car seat mold getting filled with particles. The total number of particles at the end of the simulation was a couple of hundred thousands with the simulation time still very manageable.
This offering is not approved or endorsed by OpenCFD Limited, the producer of the OpenFOAM software and owner of the OPENFOAM® and OpenCFD® trade marks. OPENFOAM® is a registered trade mark of OpenCFD Limited, the producer of the OpenFOAM software.