PIC to DEM conversion

The PIC to DEM tool allows to convert a checkpoint file obtained from a PIC run into a new checkpoint file on a custom-refined mesh with DEM particles. The DEM particles positions are initialized such that the original PIC parcels distribution (aka the solids volume fraction) is preserved in each cell up to a negligible error.

Building the PIC to DEM tool using CMake (from inside the build directory):

cmake --build ./ --target pic2dem

The following inputs must be preceded by “pic2dem.”:

	Description	Type	Default
convert	Name of the checkpoint file obtained from a previous PIC run, that will be converted to a DEM checkpoint file	string	“”
refinement_ratio	The mesh refinement ratio that will be applied on each direction to obtain a refined mesh out of the one read form the PIC checkpoint file	int	1
eps_tolerance	The threshold used for DEM particles generation from the PIC solids volfrac distribution. If ep_s in a cell is below the threshold, no DEM solids will be generated in that cell	Real	1.e-15
eps_overflow	An artifact, like a knob, for the user to force over-production (if value > 1), or under-production (if value < 1) of DEM particles	Real	1.0
small_volfrac	This input gives the possibility to set a small volfrac value just for the DEM refined case, while the standard small volfrac value will still be used for the PIC case read from the checkpoint file	Real
geom_chk_file	Name of the EB checkpoint file where the DEM refined case geometry will be read or written	string	“”
geom_levelset_chk_file	Name of the EB checkpoint file where the levelset geometry for the DEM refined case will be read or written	string	“”
geom_chk_write	Flag to turn on/off writing the EB geometry checkpoint file for the DEM refined case	bool	false
geom_chk_read	Flag to turn on/off reading the EB geometry checkpoint file for the DEM refined case	bool	false
geometry_filename	CSG filename that will be used for generating the DEM refined geometry in case the PIC coarse geometry is read from a checkpoint file	string	“”