Reply To: add gravity leads to instability, bifurcation 3D, multiphase, particles
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Thanks for the fast response and the hints:
1/ I have used the converter to convert quantities into lattice units (i.e. gravitation code line 174)
T gLB= gravity*converter.getPhysDeltaT()*converter.getPhysDeltaT()/converter.getPhysDeltaX();
I have also used the poiseuilleXd file as a starting point. However, it shows how to apply a body force, but not how the body force is connected to gravitation. I think in the LB framework OpenLB, there is so far no code that shows this connection. The LB framework palabos (palabos-v2.0r0\examples\showCases\vofMultiPhase\damBreak3d.cpp) shows that body force and gravitation (in lattice units) is the same. Code line 70,71. I assume my implementation of gravitation is fine in the bifurcation3d (see dropbox)?
2/ You are right Buoyancy forces are not considered.
3/ I get already a stable simulation result with changed boundary conditions (without gravitation). Adding gravity (1 thing changed) does not work.
I would be great if you could find a specific mistake in my code or recommendation i could change.
Thanks you very much for the help in advance