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scattering of a sphere and compared to analytical solution

Posted Feb 26, 2014, 4:21 a.m. EST Acoustics & Vibrations Version 4.3a 5 Replies

Isabel Perez
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Hi everyone

I was trying to work on the model which appears in the Model Gallery "Acoustic Scattering Off an Ellipsoid
Model ID: 12417" to describe the scattering of a solid sphere, but I got some asymetric results that I can not believe at all. In the same model ID: 12417 they talk about a second file
" acousticscatteringsphere_42a.mph - scattering of a sphere and compared to analytical solution"
but I am not able to find it for comparing with my work.
Has somebody got this file? Do you know where could I find it? Could you help me on that?
Thank you in advanced.
5 Replies Last Post Mar 25, 2014, 9:13 a.m. EDT
Stefano Firpi
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Posted: 1 decade ago Feb 26, 2014, 9:12 a.m. EST
I think you can easily edit the ellipsoid scattering file substituting the ellipse with a sphere.
That would be way faster that waiting to obtain the model you asked.
Stefano
I think you can easily edit the ellipsoid scattering file substituting the ellipse with a sphere. That would be way faster that waiting to obtain the model you asked. Stefano
Isabel Perez
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Posted: 1 decade ago Feb 27, 2014, 6:28 a.m. EST
Thank you for your suggestion, Stefano. in fact, it was what I done at first step, but the results exhibited some asymmetries that were not consistent with the geometry of the problem. Probably I am doing something wrong , it is because I'd like to compare with the sphere model.
Thank you for your suggestion, Stefano. in fact, it was what I done at first step, but the results exhibited some asymmetries that were not consistent with the geometry of the problem. Probably I am doing something wrong , it is because I'd like to compare with the sphere model.
Stefano Firpi
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Posted: 1 decade ago Mar 12, 2014, 11:18 a.m. EDT
Attach an image of the asymmetries you're talking about, it will be easier to understand.
On Friday I'll play a bit with some scattering problems and see if I find something interesting.

Try to mesh a little finer, does those asymmetries remains?
Attach an image of the asymmetries you're talking about, it will be easier to understand. On Friday I'll play a bit with some scattering problems and see if I find something interesting. Try to mesh a little finer, does those asymmetries remains?
Isabel Perez
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Posted: 1 decade ago Mar 25, 2014, 8:54 a.m. EDT
Here there are two figures corresponding to the tutorial model I referred, changing just the direction of the background pressure (now it travels in along x direction, (x,y,z= (1,0,0) ). I agree it depends on the mesh, probably, but with finer mesh I get similar (but not the same) results. they are similar in the sense that they are not symmetric, but the are not exactly the same results. Probably I am doing something wrong...
Here there are two figures corresponding to the tutorial model I referred, changing just the direction of the background pressure (now it travels in along x direction, (x,y,z= (1,0,0) ). I agree it depends on the mesh, probably, but with finer mesh I get similar (but not the same) results. they are similar in the sense that they are not symmetric, but the are not exactly the same results. Probably I am doing something wrong...
Stefano Firpi
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Posted: 1 decade ago Mar 25, 2014, 9:13 a.m. EDT
Well, take a look at those asymmetries.
They are tiny compared to everything else.
76.325 vs 76.33 dB
Zoom out a bit your polar plot and you should get your simmetric result.
Just try to refine the mesh, if the asymmetryes become smaller, those are only numerical problems (IMHO)
Stefano
Well, take a look at those asymmetries. They are tiny compared to everything else. 76.325 vs 76.33 dB Zoom out a bit your polar plot and you should get your simmetric result. Just try to refine the mesh, if the asymmetryes become smaller, those are only numerical problems (IMHO) Stefano

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