boundary condition of only direction, without value
 

Dear foamers!

I'm working on a new solver for electromagnetic transmit problems, using maxell's equations. A solver of this type could be found in COMSOL, but I decided to develop one for OF. My problem is defining the boundary condition, which is needed for any solver's future cases.

The idea of the boundary condition is to define the direction of a vector (A) to be the normal of the face, while the value is calculated implicitly. One could say it sounds familiar to "calculated" B.C., but the direction is obligated to face's normal.

Does anybody has an idea how can I implement a that condition?
I would much appreciate any help.

thank!
Or.

I have never programmed that kind of thing, but GroovyBC has the possibility of "U&normal()" [http://www.cfd-online.com/Forums/ope...-groovybc.html], maybe thats a start for your work?