@eqe
maybe helpful https://blender.stackexchange.com/questions/129870/blender-as-a-fluid-dynamics-simulator
also I'll mention Sibernetic which is a SPH sim (another is mentioned in the Stack Exchange post). I know the guys that made it and, having hacked around a bit on the code, I think it's fairly comprehensible. it is for a specific biological application though, so I offer it as a comparison more than a solution.
@2ck
FreeCAD and OpenFOAM.
@2ck good question! I'm looking for more physically accurate, although the final goal is art of a sort.