[Skaiwalker]

Hello all,

I learned a lot from the members of this awesome forum but by now I can't get my head around the hydrodynamic pressure and its point of reference:

I made a simple cuboid case, with z=0m at the bottom and z=0.1m at the top, the case is attached. I set the top plane as "fixedValue uniform 1e5" in "0/p" and "0/p_rgh" and "U=noSlip" at the entire boundary. But, as can be seen in the attached picture (top plane: boundary "air", sides show the internal mesh), the pressure distribution is wrong: It decreases from 1e5 at the bottom to ~.98e5 at the top. It should be 1e5 at the top (as stated in the boundary file) and ~1.2e5 at the bottom.

So the question is: Why is my boundary condition not accepted or what am I missing?


Background info on provided case: I want to simulate ingot melting in a crucible. The top plane represents the melt-air interface (pressure = 1e5Pa). The solver is buoyantPimpleFoam using an fvOpttion of type solidificationMeltingSource for ingot modeling. pRef cell is a cell at the top of the domain set to pRefValue 1e5.

PS: When I adjust the mesh to be z=0 at the top and z=-0.1m at the bottom the pressure distribution is right, represented by blockMeshDict_adjusted in the uploaded case.

Thank you very much in advance! Greetings
Kai