Problem: tetrahedral mesh and interFoam = bad results ?
i'm using the interFoam-solver (OF 1.6) to simulate a drop/wall-collision.
Because it is much more comfortable and time efficient (compared to blockMesh), i create the geometry and mesh with Salome. In Salome i use the "Netgen(1D,2D,3D)"-mesher to create a tetrahedral mesh.
From previous (and through experiments already validated) works, i pretty much know how the fluid-flow of the drop-impact - at least in the early phase of the simulation - should look like. In this case : The spreading wave-front has to be quiet smooth and spread nearly symmetrically in radial direction from the first point of contact between drop and wall.
When using a hexahedral mesh, the results of the simulation match the experiments pretty good.
Using a tetrahedral mesh (with approx. the same amount of cells and geometry as before) however, i get completely different and inappropriate results. The wave-front "splashes" immediatly and brakes into many little fragments.
For a better clearness, i add these two pictures from topview (both show a quarter of a droplet shortly after it touches the wall and starting to spread) :
With hexahedral mesh:
With tetrahedral mesh:
My questions are : Has someone an explanation for this discrepancy ? Is the interFoam-solver predestined for the use of hexahedral meshes ?
What could be the reasons for this numerical error?
Thanks in advance !
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