Mfem: How to determine term specific boundary term in MFEM

[kolotinsky1998]

Hi, dear community!

I use MFEM to solve a 3D electromagnetic problem for a waveguide geometry. I need to add specific term in belinear form to consider absorbing boundary conditions:

, - unknown function of electric field, and - test function. Both are defined in Nedelec complex functional space.

The problem is I can not find a way to add that bilinear form to my MFEM code. Could you help me with that issue?

Thanks in advance,
Danil

[psocratis]

Hi @kolotinsky1998

The BoundaryIntegrator you need is not currently in master.
However, I implemented it over the last weekend ( I need to test impedance boundary conditions for Maxwell too). I am doing some final tests and I will open a PR by the end of the day. In the meantime, you might want to take a look at ex25/ex25p where there is already an example of a waveguide with a PML.

Best,

Socratis

[sshiraiwa]

Hi @psocratis]. I am wondering if we can simply use VectorFEMassIntegrator for this purpose, when the element is ND.

[psocratis]

Hi @psocratis]. I am wondering if we can simply use VectorFEMassIntegrator for this purpose, when the element is ND.

Actually, yes, you are right! I hadn't realized that before. I just tested it and works fine.

Update: I see some issues with a tet-mesh. I will look into it.
Update2: No issues with a tet-mesh after all. Everything seems to work as expected.
Thanks,

@kolotinsky1998 you want to give it a try and let us know if it works for you?

Best,

Socratis

[kolotinsky1998]

Thank you very much for your help! A have tried your approach, it works for me :)