Elmer capabilities in acoustics

Numerical methods and mathematical models of Elmer
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iczajka
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Elmer capabilities in acoustics

Post by iczajka »

I've found presentation
http://www.csc.fi/english/pages/elmer/p ... alinen.pdf
that says something about Elmer capabilities in acoustics.

But I have one question: are these equations implemented yet,
is it ready to use or it need some coding?

BR
Irek Czajka
legris
Posts: 15
Joined: 30 Oct 2009, 18:56

Re: Elmer capabilities in acoustics

Post by legris »

Hi Irek

Have been using Elmer myself for acoustics.
The Hemholtz equation is indeed impelmented, you can find more info on this particular solver in the Elmer Model Manual (model 8).
If you need to include losses, you can also use the Navier-Stokes Solver.

Hope this helps,

legris
iczajka
Posts: 26
Joined: 14 Dec 2009, 13:51
Location: Poland/Kraków
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Re: Elmer capabilities in acoustics

Post by iczajka »

Thanks for reply.
I know about Helmholtz's implementation FEM and BEM, but in this presentation there are harmonic equations (Navier-Stokes?) to take insight into near wall processes.

So it is standard Navier-Stokes? Then how was imaginery part of acoustical impedance found - transient simulation?

By the way - actual implementation of Helmholtz equation includes losses.

BR
Irek
mika
Posts: 230
Joined: 15 Sep 2009, 07:44

Re: Elmer capabilities in acoustics

Post by mika »

Hi,

The linearized Navier-Stokes solver in the frequency domain is an outcome of contracted research. Unfortunately this solver is not openly available currently, so for performing time harmonic acoustic analyses the open source version of Elmer does not offer anything else than the Helmholtz solver.

- Mika
iczajka
Posts: 26
Joined: 14 Dec 2009, 13:51
Location: Poland/Kraków
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Re: Elmer capabilities in acoustics

Post by iczajka »

Hi,
is there any hope about its availability in future?
or somebody has to write it :)

I am trying to find acoustical impedance of some structure. It was relatively easy to find real part of impedance,
but how to find imaginery part?

BR
Irek
mika
Posts: 230
Joined: 15 Sep 2009, 07:44

Re: Elmer capabilities in acoustics

Post by mika »

Hi,

My impression is that these proprietary solvers will be made openly distributable in future, but I cannot guess when this will actually happen. I'm afraid that hoping it to happen in near future may be too optimistic.

-Mika
iczajka
Posts: 26
Joined: 14 Dec 2009, 13:51
Location: Poland/Kraków
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Re: Elmer capabilities in acoustics

Post by iczajka »

Thanks for info.
BR
Irek
legris
Posts: 15
Joined: 30 Oct 2009, 18:56

Re: Elmer capabilities in acoustics

Post by legris »

Mika,

Thank you for the precision with regards to the Navier-Stokes solver, was trying to use it for the first time this morning and obviously could not get it to work with a time harmonic source...

Can rights to use these proprietary solvers be purchased?

Many thanks,

Yacine
mika
Posts: 230
Joined: 15 Sep 2009, 07:44

Re: Elmer capabilities in acoustics

Post by mika »

Hi,

Unfortunately, at least for the time being, a purchasing possibility is not offered.

-Mika
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