Elmer Discussion Forum

I understand that the currently acoustic anlaysis in Elmer FEM only supports harmonic analysis but not real transient analysis, is that correct?

Do we have any plans to implement a time domain method for acoustic wave propagation, such as FDTD etc?

Thanks, Mika! For the Shell Solver, as discussed before, it gave out incorrect eigen results for box-type structures. The case you metnioned below regarding eigen analysises dones't have right corners so it might be correct. As you may understanding, right corner cases are quite common for shell str...

I recompiled the FacetShellSolve.F90 file, the result is at least changing under different frequencies. As the shell solver doens't seems to give correct results for eigen analysis and harmonic anlaysis, will you consider to update the facet shell solver to make it can couple with beam section and s...

Hi Mika, I updated the sif file as attached (moved the frequency command to the solver section), but it seems the results is still not changing under different frequencies. Do you know what the reason may be? The assembly of beam sections was added into the shell solver only, so the facet shell solv...

Thanks, Mika. Another question, for shell with beam analysis, can the FacetShell also be used or only shell solver is supported? I see, with the "Harmonic Mode" keyword the frequency must be given in the solver section, so change the place of "Frequency" command. "Harmonic M...

Hi Mika, This can give a non-zero results, but the displacement is the same under all frequencies. I assume the harmonic analysis is not carried out, is that correct? Do we have a verified shell solver examples that can carry out harmonic analysis? it seems the solver is not very stable. I think the...

Thanks, Peter. May I ask what is hierarchical simulation? is there any test case that I can follow? Hi Sure. Look at test cases "ShoeboxFsiHarmonic*". Plate may be difficult if you want pressure jump over it. Then you might need to use a 3D solid. The solution is found iterative using a bl...

Can Elmer support VibroAcoustic analysis in water? For example, a plate vibration in water and get the acoustic pressure at some point in water?

Hi Mika, Many thanks for the kind advice. I checked the results from facetshell solver, its results match with comercial software. Do you know how can use the facet shell for harmonic analysis? I used the attached sif file trying to analysis an plate under harmonic forces (applied through loads), bu...

Hi Mika, many thanks for the kind help. As you may understand, two shells meet at right angles may be common for many cases. Do you think there is alternative solvers in Elmer that can solve these kind of thin plate boxes? Will you consider to update the shell solver? In the first place the developm...