Calculated pressures change based on domain elevation using interFoam and interIsoFoam.
Summary
Calculated pressures change based on domain elevation using interFoam and interIsoFoam. As the domain is moved up in the gravity direction, pressures decrease with negative pressures forming within the water phase.
Steps to reproduce
Reproducible using weirOverflow tutorial (~/tutorials/multiphase/interFoam/RAS/weirOverflow)
Case 1: Run weirOverflow tutorial without any changes.
Case 2: Change the location of the weirOverflow domain by adding 500 to all Y-values in the blockMeshDict (y is the gravity direction for this tutorial).
Run both cases to 60 seconds. Create isoVolumes of the water phase (a=0.5). Color by "p" with a range -1 to 0. Case 2 will have negative pressures in the water phase near the free-surface. Comparison of pressures at bottom of water column also differ.
Example case
Reproducible using weirOverflow tutorial (~/tutorials/multiphase/interFoam/RAS/weirOverflow)
What is the current bug behaviour?
The pressures in the domain change based on the location of the domain with respect to the gravity direction.
What is the expected correct behavior?
I think "p" should be independent of the domain location?
Relevant logs and/or images
See attached for image comparing Case 1 and Case 2. Also reproduced in a different domain to further highlight the issue in attached image "Example2".
Environment information
Have reproduced on 2 systems OpenFOAM version : v1806|v1812 Operating system : ubuntu|openSUSE Compiler : gcc|intel
Possible fixes
Not sure....