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February 7, 2012 1:46am UTC in response to Siva Kumar Manickam

Re: animation vieweing from different reference frame

I could see in the animation setting various frames like: material, mesh, spatial and geometry. I have given moving wall boundary condition from material frame of view. How to view this from fluid reference frame? when I use moving mesh model I could see all these reference frame in action. But my physics could not be solved easily in moving mesh owing to mesh deformation. But I get proper results in stationary frame of reference.
I want to create some animation and view it from the fluid point of view. Is it possible? I have seen this kind of transofmrations in many other cfd software. Is it possible in comsol?

Please some one enlighten me...

with regards
Siva

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February 9, 2012 6:47am UTC in response to Siva Kumar Manickam

Re: animation vieweing from different reference frame

Hi

do not mix up all frames, read carefully the doc and do some simple examples.

CFD fluid motion is not directly related to the mesh motion, the ALE is used only for the fluid structure interactions, when the structure deforms and changes the overall shape of the fluid, then the meshing (mathematical sampling of the space for the CFD calulations) also deforms to follow, but the fluid flows over the mesh

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Good luck
Ivar

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February 9, 2012 8:38am UTC in response to Siva Kumar Manickam

Re: animation vieweing from different reference frame

Hi

but none of the COMSOL frames corresponds to the fluid motion frame (the boat in the stream), you are either on the shore, or on the flexible solid part in the stream, and you can show the "particles moving" but you canot look at he environment from a particle (except if you implement it via equations yourself, always possible)

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Good luck
Ivar

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February 9, 2012 12:59pm UTC in response to Siva Kumar Manickam

Re: animation vieweing from different reference frame

Hi

from my understanding you do (with COMSOL) solve from the "shore" with particle tracking giving the closest to "boat" view, or am I wrong ?

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Good luck
Ivar

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February 11, 2012 11:36am UTC in response to Siva Kumar Manickam

Re: animation vieweing from different reference frame

Hi
indeed references is always a point of view, the main difference between the moving and the fixed frame is the second derivative item of the frame itself, there are a few interesting books talking about this, among other the one(s) of Axisa, check the FORUM, the references are given a few times, and there are a few older treads on that subject

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Good luck
Ivar

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February 11, 2012 12:54pm UTC in response to Siva Kumar Manickam

Re: animation vieweing from different reference frame

Hi

what about trying a search on the Forum, with the word "Axisa" ;)

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Good luck
Ivar

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February 27, 2012 1:57am UTC in response to Ivar Kjelberg

Re: animation vieweing from different reference frame

Dear Dr. Ivar
Thank you very much. I think now I found answer.
I solve 2D spf in body-fitted frae (boat) and use another ALE mesh give the calculated velocity or displacement to the moving body. It looks 'like' the solution is solved from 'shore'.

Actually upon digging the forum further, I understood that there is spf cum ALE built in but given in twophase flow-moving mesh module, which has built in modules to serve my purpose.

Simulation runs smoothly and I am able to get the results.

Salute you sir,
Siva

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