I've just noticed a strange behavior when trying to simulate a 3D multiphase flow (2 phases, densities 7000 and 2500) :
Two liquids with different densities are separated by a wall. One removes the wall, and theoretically, one gets a final situation where the most dense liquid lies at the bottom, and the other one on the top.
But, when the two liquids get in contact, they litterally explode as if a strong repulsion force was in action.
I can send the *xml file if need be (how do I proceed ?)