yade-dev team mailing list archive

[Janek Kozicki <janek_listy@xxxxx>]

Václav Šmilauer said:     (by the date of Thu, 08 Jul 2010 20:29:23 +0200)

> > This is a "must have", but unfortunately it is not so simple. Most
> > clumps have overlapping spheres, and overlapped volumes should be
> > counted only once. Here you will get spheresVolume>totalVolume, i.e.
> > negative porosity....
> It can be approximated via sampling the affected volume, though it is
> not trivial to make it efficient for larger number of particles (you'd
> have to use bboxes somehow).

There are even more problems than overlapping spheres in a clump.
The physically relevant volume of a clump would include the voids
*inside* a clump (between spheres that make it) as a solid volume.

This is because the voids inside a clump do not ever participate in
''spare voids'' volume. After all a clump is supposed to simulate a
rough grain or such thing. If you take a real very rough grain, you
will never add the pores inside it to total volume of ''spare voids''
in the sample.

The inner voids of a clump are a solid volume.

-- 
Janek Kozicki                               http://janek.kozicki.pl/  |