LIGGGHTS-VTK
The vtk files generated by LIGGGHTS, for the particles can have any selection of variables. However, to be processed in Iota a minimum number of variables is required and the order is fixed. The same restriction affect the LIGGGHTS particle-particle and particle-geometry contacts files.
Iota supports the processing of spherical and multisphere particles. The details of how to dump the DEM simulation data to VTK files for each of the one of these cases is provided below:
Spherical particles
In the particles file, the filename must have the extension ".vtk". The variables in the command must follow :
id: column one
type: column two
x,y,z: columns three to five
vx,vy,vz: columns nine to eleven
radius: column eighteen
Additional columns can be included and they will be considered as user defined variables, and will be processed in that way. An example of the LIGGGHTS dump custom/vtk
command for the particles file is:
dump particles all custom/vtk 5000 post/vtk_ascii/particles*.vtk &
id type x y z ix iy iz vx vy vz &
fx fy fz omegax omegay omegaz &
radius
The particle-particle and particle-geometry contacts files can have any name with the extension ".vtk". An example of the LIGGGHTS dump commands for both contact files is:
compute cp all pair/gran/local id pos force
compute cw all wall/gran/local id pos force
dump Cfile all local/gran/vtk 400 contacts_particles*.vtk cp
dump Wfile all local/gran/vtk 400 contact_geometries*.vtk cw
In the case of the CAD walls/geometries, the only restriction is that all the meshes to be processed should be contained in a single vtk file per time-step for the case of moving CAD walls/geometries. In the case of static CAD wall/geometries, it is possible to just provide a single vtk file for the processing.
Example of the LIGGGHTS dump command for moving and static CAD wall/geometries files are:
Static meshes:
dump dmp_geo all mesh/vtk 400 geometries.vtk cad1 cad2 cad3
Moving meshes:
dump dmp_geo all mesh/vtk 400 geometries*.vtk cad1 cad2 cad3
A detailed description on how to use the LIGGGHTS VTK files in the coarse-graining module can be found in the Input DEM data: LIGGGHTS-VTK section.
Multisphere particles
Two set of files are required in order to process the multisphere particles data. The first set of files correspond to the sub-spheres data (similar to the particles file for spherical particles) and the filename must have the extension ".vtk". The variables in the command must follow:
id: column one
id_multisphere: column two
type: column three
x,y,z: columns four to six
vx,vy,vz: columns ten to tweleve
radius: column nineteen
Additional columns can be included and they will be considered as user defined variables, and will be processed in that way. An example of the LIGGGHTS dump custom/vtk
command for the particles file is:
dump particles all custom/vtk 5000 post/vtk_ascii/particles*.vtk &
id id_multisphere type &
x y z ix iy iz vx vy vz &
fx fy fz omegax omegay omegaz &
radius
The second set of files contain the data related to the actual particles (multispheres). In this cases, it is required to set-up a set of compute multisphere
commands that compute the properties of the multisphere particles. The data generated by these computes is exported into ASCII files (one per time-step) by means of dump local
command.The files must have the extension ".dmp". The variables in the command must follow:
angmom: columns one to three
atomtype: column four
clumptype: column five
density: column six
fcm: columns seven to nine
id_multisphere: column ten
masstotal: column eleven
omega: columns twelve to fourteen
quat: columns fifteen to seventeen
torque: columns eighteen to tweenty
vcm: columns twenty one to twenty three
xcm: columns twenty four to twenty six
An example of these LIGGGHTS commands is:
compute angmom all multisphere property angmom
compute atomtype all multisphere property atomtype
compute clumptype all multisphere property clumptype
compute density all multisphere property density
compute fcm all multisphere property fcm
compute id_multisphere all multisphere property id_multisphere
compute masstotal all multisphere property masstotal
compute omega all multisphere property omega
compute quat all multisphere property quat
compute torque all multisphere property torque
compute vcm all multisphere property vcm
compute xcm all multisphere property xcm
dump dump_ms all local 400 multispheres.*.dmp &
c_angmom[1] c_angmom[2] c_angmom[3] &
c_atomtype &
c_clumptype &
c_density &
c_fcm[1] c_fcm[2] c_fcm[3] &
c_id_multisphere &
c_masstotal &
c_omega[1] c_omega[2] c_omega[3] &
c_quat[1] c_quat[2] c_quat[3] c_quat[4] &
c_torque[1] c_torque[2] c_torque[3] &
c_vcm[1] c_vcm[2] c_vcm[3] &
c_xcm[1] c_xcm[2] c_xcm[3]
The particle-particle and particle-geometry contacts files can have any name with the extension ".vtk". An example of the LIGGGHTS dump commands for both contact files is:
compute cp all pair/gran/local id pos force
compute cw all wall/gran/local id pos force
dump Cfile all local/gran/vtk 400 contacts_particles*.vtk cp
dump Wfile all local/gran/vtk 400 contact_geometries*.vtk cw
In the case of the CAD walls/geometries, the only restriction is that all the meshes to be processed should be contained in a single vtk file per time-step for the case of moving CAD walls/geometries. In the case of static CAD wall/geometries, it is possible to just provide a single vtk file for the processing.
Example of the LIGGGHTS dump command for moving and static CAD wall/geometries files are:
Static meshes:
dump dmp_geo all mesh/vtk 400 geometries.vtk cad1 cad2 cad3
Moving meshes:
dump dmp_geo all mesh/vtk 400 geometries*.vtk cad1 cad2 cad3
A detailed description on how to use the LIGGGHTS VTK files in the coarse-graining module can be found in the Input DEM data: LIGGGHTS-VTK section.
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