DG Jumps on Surfaces

NGSolve
1

Hi everyone,

is there a way to implement DG jumps (interior penalty) for surface elements? I’ve tried a couple of variants (switching Trace() and Other(), element_boundary loops), but I don’t seem to get any contribution to the stiffness matrix (see mwe below).

Best,
Henry

from netgen.occ import unit_cube
from ngsolve import *

mesh = Mesh(unit_cube.GenerateMesh(maxh=2))

V = VectorSurfaceL2(mesh, order=1, dgjumps=True)
u, v = V.TnT()
h = specialcf.mesh_size

a = BilinearForm(V)
a += 1 / h * (u.Trace() - u.Other().Trace()) * (v.Trace() - v.Other().Trace()) * ds(skeleton=True)
a.Assemble()
print(Norm(a.mat.AsVector()))
2

dg I think not, hdg should work with SurfaceFacet space

3

Okidoki. Thank you for letting me know!