BUG: processorFaPatch: incorrect deltaCoeffs calculation for corner processor edges of non-planar meshes

Summary

When a corner edge of a non-planar finite-area mesh is shared by two processors, the edge is observed causing a subtle minus/plus perturbation in the tangential direction. Later, this perturbation propagates downstream and leads to an unexpected film separation for a particular case.

pack_2074_corner_processor_fa_edge_24Oct24.zip

Steps to reproduce

Execute Test-faMesh-edgeInterpolation.zip on finite-area-test-case-deltaCoeffs.zip in serial and parallel modes, and compare the output fields.

Example case

Environment information

• api = 2406
• HEAD = e4f4c73b
• compiler = Clang (system) = clang version 15.0.7
• mpi = SYSTEMOPENMPI = mpirun (Open MPI) 1.10.7.0.5e373bf1fd
• OS = Description: openSUSE Leap 15.5
• opts = linux64ClangDPInt32Opt

Possible fixes

The problem has been traced to differences in the deltaCoeffs at the processorFaPatch level. The suggested solution is to apply the same algorithm used for internal edges to the processor edges as well.