← Back to team overview

yade-users team mailing list archive

Re: [Question #695164]: Interparticle spacing

 

Question #695164 on Yade changed:
https://answers.launchpad.net/yade/+question/695164

    Status: Answered => Open

Othman Sh is still having a problem:
Hello all,

As an update about using Delaunay triangulation of the FlowEngine,
printVerticies [1] gave me a list of the vertices but they are not
grouped for each tetrahedron (i.e Delaunay tetrahedon). Instead, they
are listed based on the bodies ids. So I cannot use them to calculate
the distances between the adjacent particle centers because I don't know
if body #1 is actually the neighbor of body #2.

To solve this issue, I used getCellVolume [2] to compute the volume of
the cells which I think it is the volume of the tetrahedrons. Then from
each tetrahedron volume, I can get the length of the sides of that
tetrahedron (volume= side length^3 / 6*sqrt(2))) which should be equal
to the distance between the centers of the particles forming the
tetrahedron. My question here is:

- Does "cell" in getCellVolume means the tetrahedron element? I just want to confirm if my approach is correct
- Is there any error in this approach that I am not aware of?

Jerome, 
That seems right because I checked O.interactions.countReal() and this returned zero. Is this because there is no contact between the spheres? how to make the interactions real in this case? I want to count the interparticle spacing for the initial packing state (i.e. before running any simulation).

Jan,

That would be a good idea too. However, I couldn't find a function that
can give the positions of the Delaunay tetrahedrons corners. There is
computeVolumes [3] to compute the volume of Voronoi cells but this will
not be useful because I think Voronoi cells are not the same as the
Delaunay tetrahedron (right?), so I can't use that in calculating the
interparticle spacing.

Thanks,
Othman

[1] https://yade-dem.org/doc/yade.wrapper.html#yade.wrapper.FlowEngine.printVertices
[2] https://yade-dem.org/doc/yade.wrapper.html#yade.wrapper.FlowEngineT.getCellVolume
[3] https://yade-dem.org/doc/yade.wrapper.html#yade.wrapper.TesselationWrapper.computeVolumes

-- 
You received this question notification because your team yade-users is
an answer contact for Yade.