On 7 Nov 2018, at 13:16, Floriane Gidel [RPG] <mmfg@leeds.ac.uk> wrote:
Hi David,
It would be again a disk centered in a square domain and I need the square boundaries to be periodic both in x and y. Now I'm solving a simple problem with a solution u_p in the plane and u_d in the disk that are only y-dependent and satisfy:
Delta_y u_p = 0 in the plane grad_y u_p . n_y = n_y at the disk/plane interface. u_p periodic
Delta_y u_d = 0 in the disk grad_y u_d . n_y = n_y at the disk/plane interface. int (u_d) dx(disk) = 0
Note that n_y at the disk/plane interface is equal to sin(theta), which will therefore be the source term in the weak formulations.
So the two problems can be solved independently, but the domain must contain both the disk and the surrounding plane in both cases to apply the condition at the interface (or we need to make sure that the interface nodes are at the same location in both meshes). At the moment I use triangular mesh with CG1 basis functions, but that is quite flexible.
You can make a topologically periodic square mesh with: PeriodicUnitSquareMesh(..., direction="both") I think that's what you want? Cheers, Lawrence