<html><head><style type='text/css'>p { margin: 0; }</style></head><body><div style='font-family: times new roman,new york,times,serif; font-size: 12pt; color: #000000'>All,<br><br>Does GetDP support Floquet BCs for periodic structures? I'd like to apply this to EM fields in traveling wave tubes such as helix and coupled cavity structures, etcetera. I don't see why Floquet conditions wouldn't be similarly applicable to other wave propagation in periodic structures, such as phonons in a crystal.<br><br>Of course, there is the separate issue of whether GMSH supports the generation of such a mesh, though I'm sure it wouldn't be a complicated workaround. The 2D mesh at the origin would have to match the mesh at the periodic boundary but with all the nodes translated by that period.<br><br>Let's say the periodicity is in Z, if we define one 2D mesh at Z = 0, and the same mesh at Z = L (same node and element numbers), then the element calculations just to the one side of L would have to do the calculations with translated values of Z (and, of course, the phase-shifted values from the surface mesh).<br><br>Regards,<br>Dan<br><br>BTW: An alternative is to include several periods of the structure and identify the eigenstates. Computation times are horribly longer and this solution doesn't provide a continuum to DC (or omega -> 0). <br></div></body></html>