Hey qr. Thank you for the help! Ill try answer your questions in order to give the best picture, and ill have to collect more photos when I am back from work this afternoon. - Im not sure if the problem is at the cell or the interface, I assume you mean cell face? I can have another look tonight, I am new to OpenFoam though so I have trouble visualising things. - IM not sure which figure is called I, but theres are respectively the; external 3D view (alpha), sectioned 3D vire (alpha), 2D view (alpha) where you can see the liquid profile in the vial red = liquid, blue = vapour. Next fig is the 2D temperature profile, Next the 2D U field showing flow concentration onto the anomaly, and finally the pressure feild. - I havent tried changing the decomposer, I will try this, I have tried running the simulation without decomposition and it did not produce an external ‘wart’ like seen in the figures but a sort of internal one, but due to the time cost of this simulation I havent run enough tests to see if it eventually will produce an external wart (for the exact same case setup but rerun of decomposePar the warts will appear in random places. Sometimes there will be no external wart, but the flow will concentrate on an internal point in the flow in an unphysical way similar to an external wart but internally< so im not sure wether this is the same problem or not; this is the same result I have had on some decomposed runs and both of my undecomposed runs). - Ill try RenumberMesh, thanks! Ive been using netgen3d on SALOME to make my meshes and then ideasunvtofoam, which im fairly certain makes tetrahedral meshes. Maybe Ill have to have a look at the cell shapes, but I have 100k cells over a 6mm OD, 80mm length tube so I believe it is somewhat good quality? Othogolanity is only around 50%.