Generalized Neumann BC q f nc grad f%3dg

maddhi

Good day everyone!

Are generalized Neumann boundary conditions available in OpenFOAM?

In case the expression "q f + n.(c grad f)=g" is not quite clear, what I mean is:
"q f" is the field f scaled by a factor q
"n.(c grad f)" is the scalar product of the surface normal n with the gradient of f scaled by c. (c may be tensorial).

If this BC is not available, maybe someone could be so kind to give a rough idea of how it could be implemented? Which classes are best used as a basis, which files do I need to modify?

I have seen the mixedFvPatchField, but it seems not to implement the generalized Neumann BC, instead it is a "linear transition" between fixedValue and fixedGradient BC. Am I right?

I don't see which physical meaning this mixed BC has, and I didn't find it in any of the tutorials. Can you suggest any demonstrative situation that would require the mixed BC? Just for curiosity.

Thanks
Maddhi