What FEspace is HDivSurface

Is it BDM or RT? When I set e.g. order=3, does that mean that the divergence space is SurfaceL2, order=2?

Best regards,

Alvar

Hi Alvar,

you can think of the HDivSurface as the 2D HDiv space mapped onto the surface.
With order=3 you get the BDM_3 space and thus the divergence should be in SurfaceL2 with order=2.

Best,
Michael

Hi Michael,

Thank you for your reply and the clarification. Just out of curiosity, as I understand it the construction of the FE-space would also be possible with Raviart-Thomas elements. Is there a way one could use these elements?

Best regards,

Alvar

Hi Alvar,

using gives the Raviart-Thomas elements (for triangles and tetrahedra), which lie between polynomials of order k and k+1 and the divergence is then in L2 of order k.

For HDivSurface this option is currently not implemented in the main code, but it might come soon.

Best,
Michael

The Raviart-Thomas elements should now be available for the HDivSurface space for the latest nightly build version.