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PML for SAW interdigital transducer

Posted 12 mars 2012, 23:19 UTC−4 Acoustics & Vibrations, Geometry, Parameters, Variables, & Functions, Studies & Solvers, Structural Mechanics Version 4.2a 5 Replies

Juan Bravo
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Hi, i'm trying to simulate an interdigital transducer for SAW on a lithium niobate substrate but i have a lot of problems adding PML. I have previously simulated using periodic conditions but now i'm trying to simulate the transducer with the actual measures, to avoid the reflections on the material frontiers i'm using PML.

I have created 2 semicircular geometries on each side of the substrate and one rectangular on the bottom in order for the wave to propagate and dissapear along them. I included PML in definitions as is the new method in version 4.2 and linear elastic material (with LiNbO3 elasticity) for these geometries but when i try to simulate it gives error about the coordinates in the semicircular PMLs.

I tried rectangular and cylindrical (with center in the origin and in what would be the center of the circle) and nothing. Tried different PMLs for each geometry which didn't work and just one for all which simulates but doesn't work as it should (no attenuation in the semicircles).

Please has anyone worked with PMLs in acoustics in version 4.2 and is able to help me with this? i can upload the file if it's necessary.

Thanks!
5 Replies Last Post 12 avr. 2013, 10:38 UTC−4
Juan Bravo
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Posted: 1 decade ago 13 mars 2012, 10:33 UTC−4
Can anybody help me?

The error i get from comsol is "Comsol could not find any spherical or cylindrical regions."

Here are the 2 files i created, one with a PML definition for all the regions and one with a PML for each region.

Thanks in advance!!
Can anybody help me? The error i get from comsol is "Comsol could not find any spherical or cylindrical regions." Here are the 2 files i created, one with a PML definition for all the regions and one with a PML for each region. Thanks in advance!!
Yevgeniy Davletshin
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Posted: 1 decade ago 13 mars 2012, 11:59 UTC−4
www.comsol.com/community/forums/general/thread/26840/
http://www.comsol.com/community/forums/general/thread/26840/
Juan Bravo
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Posted: 1 decade ago 13 mars 2012, 20:44 UTC−4

www.comsol.com/community/forums/general/thread/26840/


Thanks, i already saw that bug but even tough the geometries are in the order of micrometers i'm already working everything in meters as you can see in the files i uploaded.
[QUOTE] http://www.comsol.com/community/forums/general/thread/26840/ [/QUOTE] Thanks, i already saw that bug but even tough the geometries are in the order of micrometers i'm already working everything in meters as you can see in the files i uploaded.
David Parks
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Posted: 1 decade ago 11 avr. 2013, 09:38 UTC−4
Did you ever figure this out? I have the identical issue..
Did you ever figure this out? I have the identical issue..
Juan Bravo
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Posted: 1 decade ago 12 avr. 2013, 10:38 UTC−4
Hi, yes PMLs worked for us giving them rectangular geometries, a scalling factor of 1 and curvature of 2. That's all i can remember since i'm long gone from that project.
Hi, yes PMLs worked for us giving them rectangular geometries, a scalling factor of 1 and curvature of 2. That's all i can remember since i'm long gone from that project.

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