Gravity and Archimedes

Submitted by tdl on Wed, 02/15/2012 - 13:36

Noob question.
I would like to simulate particles falling down in a container filled with water. For now I do not need to couple with CFD, but I would like to able to tell the simulation that once the particles reach a given region, they are subject to an Archimedean lift.
But I am not sure how I can do it? Any simple example that I may have missed?
Thanks!

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ckloss's picture

ckloss | Fri, 02/17/2012 - 10:57

Hi tdl,

in this case you could create your own forcemodel to do that - just take fix_addforce.h/cpp as example.

Cheers, Christoph

tdl | Fri, 02/17/2012 - 15:03

Dear Christoph,
thank you for your help.
I guess there is no way to unfix some particles that are in a geometric region?
What I do mean is this:
Region A, above, air.
Region B, below, water.
Particles fall from A, where they have a fix gravity 9.8.
A some later time step, a particle moves from A to B.
There, i unfix gravity for said particle, and fix another
gravity adjusted by the density ratio.
I will have a look at the source, although i am weak in c++ ;-p
Regards,
Alessandro