Search found 20 matches

by Tom
12 Jan 2019, 20:11
Forum: ElmerSolver
Topic: Accuracy of results / microwave waveguide
Replies: 19
Views: 11108

Re: Accuracy of results / microwave waveguide

Sure, here it is: Figure 4.png You can clearly see the difference by comparing the dashed line in figure 3 with the light orange line in figure 4. For the results in figure 4 I used your modified sif/f90 files, ILUT as preconditioner and a threshold level of 1.0e-4. Also, your modification enabled m...
by Tom
11 Jan 2019, 12:31
Forum: ElmerSolver
Topic: Accuracy of results / microwave waveguide
Replies: 19
Views: 11108

Re: Accuracy of results / microwave waveguide

With ILUT as preconditioner and relatively small values for the ILUT tolerance the system converges even for a more complex case than the given one. This comes at a cost of longer computation time. For the waveguide filter, Elmer's second order results are now on a similar level as the results from ...
by Tom
08 Jan 2019, 18:29
Forum: ElmerSolver
Topic: Accuracy of results / microwave waveguide
Replies: 19
Views: 11108

Re: Accuracy of results / microwave waveguide

Hi Peter,

Happy new year and thanks you for looking into it! With your modified sif file computation time is indeed reduced a lot. For the second order edges, what in particular can I do to improve the results?

Tom
by Tom
20 Dec 2018, 15:57
Forum: ElmerSolver
Topic: Accuracy of results / microwave waveguide
Replies: 19
Views: 11108

Re: Accuracy of results / microwave waveguide

Dear Peter,

Have you had a chance to run the case?

Tom
by Tom
14 Dec 2018, 16:37
Forum: ElmerSolver
Topic: Accuracy of results / microwave waveguide
Replies: 19
Views: 11108

Re: Accuracy of results / microwave waveguide

Hmm, convergence might be an issue. I didn’t check the command line output due to the relatively long computation time (size of screen buffer was too small to scroll back). Maybe I should redirect the output to a file in future. My case makes use of a Fortran subroutine; I’ve attached the libraries ...
by Tom
12 Dec 2018, 18:41
Forum: ElmerSolver
Topic: Accuracy of results / microwave waveguide
Replies: 19
Views: 11108

Re: Accuracy of results / microwave waveguide

Dear all, For the sake of completeness a comparison between linear and quadratic elements is shown in the figure below. The computation times were: a/8 linear: 10.6 mins a/8 quadratic: 5.8 days a/16 linear: 1.1 days a/20 linear: 5.6 days For my application I would prefer a finer mesh and linear elem...
by Tom
29 Nov 2018, 10:30
Forum: ElmerSolver
Topic: Accuracy of results / microwave waveguide
Replies: 19
Views: 11108

Re: Accuracy of results / microwave waveguide

Hi Matthias!

Great -- thanks for the link ...

Tom
by Tom
28 Nov 2018, 15:23
Forum: ElmerSolver
Topic: Accuracy of results / microwave waveguide
Replies: 19
Views: 11108

Re: Accuracy of results / microwave waveguide

Hi Peter,

I can confirm that the waveguide test cases run using quadratic elements (and it seems also my model does) with a current version of Elmer. Unfortunately the 8.2 windows version is outdated; will there be current binaries in the (near) future?

Tom
by Tom
27 Nov 2018, 13:41
Forum: ElmerSolver
Topic: Accuracy of results / microwave waveguide
Replies: 19
Views: 11108

Re: Accuracy of results / microwave waveguide

Dear Matthias, dear Peter! Thanks a lot for your hints. I added the lines "Quadratic Approximation = Logical True" and "Use Piola Transform = Logical True" to my sif file. Then I changed the element order by creating quadratic elements a) in Salome, b) in Gmsh, and c) with elmerg...
by Tom
26 Nov 2018, 16:37
Forum: ElmerSolver
Topic: Accuracy of results / microwave waveguide
Replies: 19
Views: 11108

Accuracy of results / microwave waveguide

Dear all, I would like to use elmer for the simulation of passive HF components. To check the accuracy of elmers‘s results, I compared the calculated return loss (S11) of different solvers for a bandpass filter design published by Zhai et al. The same meshes were used for all solvers having a maximu...