Insulating boundary condition for convection–diffusion equations for Boundary pde problems
I am trying to solve convection–diffusion (CD) equation on a unit sphere. I will be solving the CD equation only on the surface of the sphere with the concentration conserved all the time. In other words, no flux comes in or goes out of the surface of unit sphere.
How can I implement such insulating boundary conditions on the surface ?
I cannot set the concentration or derivative of the concentration to be zero on the boundary.
Will appreciate any quick help.
I haven't tried applying yet.
Simplifying the question: How to make the concentration conservative using boundary conditions?
There are at least two ways of doing this, both described in the numerical experiments section of this paper.