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Pressure Acoustic, boundary element interface

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hello,everyone! I had already simulated the sound propagation issues in free space and semispace by comsol Pressure Acoustic boundary element interface,but now I was having problem simulating the same sound propagation issues in a layered waveguide(just like the ocean waveguide),because I can only set just one symmetric/infinite sound hard or antisymmetric/infinite sound soft boundary in one direction, that is to say I could only set the water surface as a antisymmetric/infinite sound soft boundary or set the bottom as a symmetric/infinite sound rigid boundary, but actually I need both of them. Is there any way to make it possible by Pressure Acoustic(BEI)? Any reply will be helpful,thanks all.


6 Replies Last Post 12.04.2022, 14:56 GMT-4
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Posted: 3 years ago 08.04.2022, 04:34 GMT-4

It is unclear why you at the same time want symmetry and anti-symmetry at a boundary.

-------------------
René Christensen, PhD
Acculution ApS
www.acculution.com
info@acculution.com
It is unclear why you at the same time want symmetry and anti-symmetry at a boundary.

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Posted: 3 years ago 11.04.2022, 09:40 GMT-4
Updated: 3 years ago 11.04.2022, 09:40 GMT-4

It is unclear why you at the same time want symmetry and anti-symmetry at a boundary.

Dear sir, Maybe I didn't make my statement very clear. For example,what I want is to have a anti-symmetry boundary at z=0 and a symmetry boundary at z=z0, you know just like the sea level and the bottom. Or a symmetry boundary at z=0 and a symmetry boundary at z=z0 to simulate roof and floor of a room separately.

>It is unclear why you at the same time want symmetry and anti-symmetry at a boundary. Dear sir, Maybe I didn't make my statement very clear. For example,what I want is to have a anti-symmetry boundary at z=0 and a symmetry boundary at z=z0, you know just like the sea level and the bottom. Or a symmetry boundary at z=0 and a symmetry boundary at z=z0 to simulate roof and floor of a room separately.

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Posted: 3 years ago 12.04.2022, 05:18 GMT-4

Ah okay. The symmetry conditions presumably alters the Green's function in the underlying integral equation to take into account the mirror source(s), but to get the additional plane you would probably need to have some explicit geometry with the desired boundary conditions. Perhaps there is a more elegant way to do it, but it depends on your application. But it sounds more like an interior problem, so perhaps FEM instead of BEM is better option for you anyway.

-------------------
René Christensen, PhD
Acculution ApS
www.acculution.com
info@acculution.com
Ah okay. The symmetry conditions presumably alters the Green's function in the underlying integral equation to take into account the mirror source(s), but to get the additional plane you would probably need to have some explicit geometry with the desired boundary conditions. Perhaps there is a more elegant way to do it, but it depends on your application. But it sounds more like an interior problem, so perhaps FEM instead of BEM is better option for you anyway.

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Posted: 3 years ago 12.04.2022, 09:15 GMT-4
Updated: 3 years ago 12.04.2022, 09:17 GMT-4

Thanks for your reply

Thanks for your reply

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Posted: 3 years ago 12.04.2022, 09:16 GMT-4

Ah okay. The symmetry conditions presumably alters the Green's function in the underlying integral equation to take into account the mirror source(s), but to get the additional plane you would probably need to have some explicit geometry with the desired boundary conditions. Perhaps there is a more elegant way to do it, but it depends on your application. But it sounds more like an interior problem, so perhaps FEM instead of BEM is better option for you anyway.

Thanks for your reply. Exactly it sound likes an interior problem and I have already tried FEM in the beginning, but the geometric scale and frequency range that I want to study is quite large and therefore you know FEM takes lots of memory and time to solve the problem so I switch my sight to BEM for a way. At last,thanks for your advice.

>Ah okay. The symmetry conditions presumably alters the Green's function in the underlying integral equation to take into account the mirror source(s), but to get the additional plane you would probably need to have some explicit geometry with the desired boundary conditions. Perhaps there is a more elegant way to do it, but it depends on your application. But it sounds more like an interior problem, so perhaps FEM instead of BEM is better option for you anyway. Thanks for your reply. Exactly it sound likes an interior problem and I have already tried FEM in the beginning, but the geometric scale and frequency range that I want to study is quite large and therefore you know FEM takes lots of memory and time to solve the problem so I switch my sight to BEM for a way. At last,thanks for your advice.

Acculution ApS Certified Consultant

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Posted: 3 years ago 12.04.2022, 14:56 GMT-4

Ah okay. The symmetry conditions presumably alters the Green's function in the underlying integral equation to take into account the mirror source(s), but to get the additional plane you would probably need to have some explicit geometry with the desired boundary conditions. Perhaps there is a more elegant way to do it, but it depends on your application. But it sounds more like an interior problem, so perhaps FEM instead of BEM is better option for you anyway.

Thanks for your reply. Exactly it sound likes an interior problem and I have already tried FEM in the beginning, but the geometric scale and frequency range that I want to study is quite large and therefore you know FEM takes lots of memory and time to solve the problem so I switch my sight to BEM for a way. At last,thanks for your advice.

You can of course also do interior BEM but perhaps you should sketch your problem or upload the file

-------------------
René Christensen, PhD
Acculution ApS
www.acculution.com
info@acculution.com
>>Ah okay. The symmetry conditions presumably alters the Green's function in the underlying integral equation to take into account the mirror source(s), but to get the additional plane you would probably need to have some explicit geometry with the desired boundary conditions. Perhaps there is a more elegant way to do it, but it depends on your application. But it sounds more like an interior problem, so perhaps FEM instead of BEM is better option for you anyway. > >Thanks for your reply. Exactly it sound likes an interior problem and I have already tried FEM in the beginning, but the geometric scale and frequency range that I want to study is quite large and therefore you know FEM takes lots of memory and time to solve the problem so I switch my sight to BEM for a way. At last,thanks for your advice. You can of course also do interior BEM but perhaps you should sketch your problem or upload the file

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