It seems that EMWaveSolver and WhitneyAVHarmonicSolver both has functionalities for an eigenvalue problem. I tried both solvers and got plausible eigenvalues. So I share my test cases here. Unzip the file and read "readme" in there. Below forum topic also gave me useful information. https://elmerfem.org/forum/viewtopic.php?t=7960
Attached picture is electric field modes (z-component, Ez) obtained by EMWaveSolver. A few comments:
- Although the calculated eigenfrequencies match theoretical predictions well, some of the shapes of the spatial modes don't quite look unique to the corresponding eigenvalues. They sometimes lack symmetry. Maybe they are too sensitive to frequencies. Experimenting on error tolerance etc is necessary. Some of modes lead to larger L2 norm even if the eigenvalue looks correct.
- WhitneyAV solver doesn't export scalar potential properly and exports no electric fields.
- While EMWave solver only exports real part of electric fields (complex part always zero), WhitneAV exports complex fields.
- In this case, a nonezero component of magnetic flux density exported by WhitneyAV is By, which I thought a bit strange when I expected to get the same results as Ez from EMWaveSolver. Maybe I'm wrong.
Thank you,
Tommy.