arbitrary shape with curved edge

Submitted by manjura on Fri, 06/28/2013 - 00:25

Hello all,

I need to put particles on a curved surface. In OpenFoam I can do that easily using blockMesh, but for DEM part, how can I create the wavy region to insert particles?

I used gmsh to create the curved surface with the same coordinate i used in blockMesh and saved them as .stl file to read by DEM.

When i run the file it shows the following error:
ERROR: Fix insert/stream (id ins): command requires a planar face for insertion (fix_insert_stream.cpp:230)

How can i insert partcle in a curved/wavy surface.
Any suggestion will be appreciated.


jtvanlew | Fri, 06/28/2013 - 05:36

Do you wish to have the particles sitting atop the wavy surface? Is it just a single layer of particles or many layers that are upon the curved surface?

You might be better served with the fix insert/pack for which you specify a region above the wavy surface to allow the particles to fall upon it.


manjura | Fri, 06/28/2013 - 08:06

Yes. I should have multiple layers of particles on wavy surface. For insert/pack, how could i create a region above the wavy surface?

Have any idea?



jtvanlew | Fri, 06/28/2013 - 08:12

i'm not sure if you need the insertion volume to trace the wavy surface, but if you can do a simple block it'd just be something like...

define the region:
region bc block -0.1 0.1 -0.1 0.1 0. 1. units box

where there's a cube with xmin, xmax, ymin, ymax, zmin, zmax dimensions.

then some code for defining your particles...
fix pts1 all particletemplate/sphere 1 atom_type 1 density constant 3600 radius constant 0.01
fix pdd1 all particledistribution/discrete 54651 1 pts1 1.0

and then finally the insertion command:
fix ins all insert/pack seed 100001 distributiontemplate pdd1 vel constant 0. 0. -0.1 insert_every 10000 overlapcheck yes all_in yes particles_in_region 1000 region bc

this might not be exactly what you're looking for but I hope it sends you in the right direction.


manjura | Fri, 06/28/2013 - 08:44

Yes, I did that part of simple block. But now I have to insert particles in a wavy bottom region. Though i create wavy surface , but I didn't find a way to create that wavy region.

Thanks for your ideas anyway.


ckloss's picture

ckloss | Fri, 06/28/2013 - 13:44

Hi manjura,

you can use the region mesh/tet command


manjura | Sun, 06/30/2013 - 05:22


Thanks for your suggestion.

I created a wavy region with gmsh as .vtk file to compatible with the 'region mesh/tet command'....but it still shows the following error now-

WARNING: VTK file contains other types than tetrahedra - only tets are currently supported in LIGGGHTS, other cells are discarded (input_mesh_tet.cpp:276)
ERROR on proc 0: This feature is not available for tet mesh regions (region_mesh_tet.cpp:141)

Any help?