Hello everyone,
I solved the Poisson equation around a surface and got an approximate of the electric potential. Now, I’m using the following line in order to get the Electric field due to that potential.
E = project(-grad(u), VectorFunctionSpace(mesh, 'DG', 0))
The problem is that whenever I increase the number of elements, the electric field also increases considerably (at the same potential), which physically speaking doesn’t make much sense. Is there another way to generate the Efield?