Running coupled CFD-DEM simulations

Description:

This article summarizes the basics on how to couple Aspherix® with CFDEM®coupling. For further details, please refer to the CFDEM®coupling documentation.

Requirements:

For this tutorial you need OpenFOAM® and CFDEM®coupling the be compiled on your system.

Setting up and starting a coupled run:

A coupled run consists of a separate CFD and a separate DEM run which hare usually located in separate folders, named accordingly. Both can be set up independently and then be adapted to run in a coupled manner.

In the DEM input script, the enable_cfd_coupling command is required :

enable_cfd_coupling

This command should be put before the configuration of the output. In general, after the configuration of particle insertions is a recommended location.

For the CFD side, the use of a CFDEMcoupling solver along with its configurations is necessary. This topic is covered in depth in the CFDEMcoupling documentation.

To run the coupled simulation, the cfdemSimulate command (to be found in the CFDEM®coupling documentation) can used. This command wraps the bash script discussed below in a single command.

Alternatively, you can also start Aspherix and the CFDEMcoupling solver manually. Both processes need to be started alongside as independent tasks. They then set up communication, etc. by themselves. To start the coupled simulation, the following script can be used:

# start jobs
cd ../DEM
mpirun -np 4 aspherix -in run.asx &
cd ../CFD
mpirun -np 4 cfdemSolverPiso -parallel