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PML error

Yevgeniy Davletshin
Hi all,

Can someone point me what I do wrong?
I tried to repeat Scattering from plasmonic nanosphere model, so I have Au sphere + Air domain (sphere) +PML/ABC domain (sphere).

When I defining PML as spherical type I'm getting error that Comsol could not find any spherical or cylindrical regions.


17 Replies Last Post Mar 7, 2016, 2:30 PM EST
Alexander Kuznetsov
Posted: 6 years ago Mar 12, 2012, 12:53 PM EDT
Make sure you have correct center coordinate in PML's settings
Make sure you have correct center coordinate in PML's settings

Yevgeniy Davletshin
Posted: 6 years ago Mar 12, 2012, 1:48 PM EDT
Any examples?
Any examples?

Alexander Kuznetsov
Posted: 6 years ago Mar 12, 2012, 2:04 PM EDT
Radome antenna is a good one. Also uploading your model might help :)

Radome antenna is a good one. Also uploading your model might help :)

Yevgeniy Davletshin
Posted: 6 years ago Mar 12, 2012, 2:17 PM EDT
Ok
Hear is a sample.
If you try to go to Study -> Solve config -> and reach Show Default Solver it will give me instant error.

Thanks for help.
Ok Hear is a sample. If you try to go to Study -> Solve config -> and reach Show Default Solver it will give me instant error. Thanks for help.


Alexander Kuznetsov
Posted: 6 years ago Mar 12, 2012, 2:54 PM EDT
Looks like a bug to me. Your settings are all fine.

To make it working, change "units" under geometry to meters. Then scale you sphere back to nanometers by multiplying all the dimensions by 1E-9. After doing that, default solver can be created.

I'd write to support. If you do, please let us know their answer. Thanks!
Looks like a bug to me. Your settings are all fine. To make it working, change "units" under geometry to meters. Then scale you sphere back to nanometers by multiplying all the dimensions by 1E-9. After doing that, default solver can be created. I'd write to support. If you do, please let us know their answer. Thanks!

Yevgeniy Davletshin
Posted: 6 years ago Mar 12, 2012, 3:09 PM EDT
Thank you for help Alex.

You are right about nanometer BUG.

I'll contact support and will update this thread after they will reply me.

Thank you for help Alex. You are right about nanometer BUG. I'll contact support and will update this thread after they will reply me.

Yevgeniy Davletshin
Posted: 6 years ago Mar 13, 2012, 6:34 AM EDT
Hi Yevgeniy,

Thanks for reporting this issue. It is a bug, occurring when using [nm] and
sometimes [um] together with spherical or cylindrical PMLs. The fix will be
included in our next release. In the meantime, the easiest workaround is to
set up your geometry in [m] instead.

The problem could technically arise in acoustics models as well, but those
only very rarely use such small units.

I agree that it would make sense to report this in a knowledge base entry.
I will create one as soon as I get the chance.

Best regards,

Linus
COMSOL Support
Hi Yevgeniy, Thanks for reporting this issue. It is a bug, occurring when using [nm] and sometimes [um] together with spherical or cylindrical PMLs. The fix will be included in our next release. In the meantime, the easiest workaround is to set up your geometry in [m] instead. The problem could technically arise in acoustics models as well, but those only very rarely use such small units. I agree that it would make sense to report this in a knowledge base entry. I will create one as soon as I get the chance. Best regards, Linus COMSOL Support

Alexander Kuznetsov
Posted: 6 years ago Mar 13, 2012, 2:15 PM EDT
Great, thanks for sharing!
Great, thanks for sharing!

Posted: 6 years ago Mar 19, 2012, 4:51 PM EDT
Thanks for pointing out this bug. I have the same problem in my model and I cannot figure out why and try to post on this forum to look for the solution. Now, I know I can do nothing about this bug but only change the unit setting. I hope this problem will be solved in the next version.
Thanks for pointing out this bug. I have the same problem in my model and I cannot figure out why and try to post on this forum to look for the solution. Now, I know I can do nothing about this bug but only change the unit setting. I hope this problem will be solved in the next version.

Evelyn Livermore
Posted: 5 years ago May 20, 2012, 7:22 AM EDT

Hi Yevgeniy,

Thanks for reporting this issue. It is a bug, occurring when using [nm] and
sometimes [um] together with spherical or cylindrical PMLs. The fix will be
included in our next release. In the meantime, the easiest workaround is to
set up your geometry in [m] instead.

The problem could technically arise in acoustics models as well, but those
only very rarely use such small units.




I'm getting the same error, but with [mm]. I am using MF-Solid Mechanics. The PMLs are in the Solid Mechanics physics. Should I correct to [m] instead? or might there be something other wrong with my model.
[QUOTE] Hi Yevgeniy, Thanks for reporting this issue. It is a bug, occurring when using [nm] and sometimes [um] together with spherical or cylindrical PMLs. The fix will be included in our next release. In the meantime, the easiest workaround is to set up your geometry in [m] instead. The problem could technically arise in acoustics models as well, but those only very rarely use such small units. [/QUOTE] I'm getting the same error, but with [mm]. I am using MF-Solid Mechanics. The PMLs are in the Solid Mechanics physics. Should I correct to [m] instead? or might there be something other wrong with my model.

Nishtha Chopra
Posted: 4 years ago Dec 24, 2013, 9:27 AM EST
I am having the same error, my dimensions have to be in mm. However, they look weired when I try them in meters. I am beginner so don't have much knowledge about the software. It would be great to have some suggestions.

I am also attaching my file for more information.

Regards,

Nishtha
I am having the same error, my dimensions have to be in mm. However, they look weired when I try them in meters. I am beginner so don't have much knowledge about the software. It would be great to have some suggestions. I am also attaching my file for more information. Regards, Nishtha


Posted: 3 years ago Jun 12, 2014, 11:11 AM EDT
yes, it is really a bug. set the unit to [m], the error disappear
yes, it is really a bug. set the unit to [m], the error disappear

Posted: 3 years ago Jun 12, 2014, 10:15 PM EDT
I found that if the PML layer is not a standard rectangle, circle or circular ring then comsol always show could not find any spherical or cylindrical ...

In my example, the outside region is a bit arbitrary, and the region can not be set as a PML layer.

I was wondering if PML layer mus be a standard rectangle, circle or circular ring region?
I found that if the PML layer is not a standard rectangle, circle or circular ring then comsol always show could not find any spherical or cylindrical ... In my example, the outside region is a bit arbitrary, and the region can not be set as a PML layer. I was wondering if PML layer mus be a standard rectangle, circle or circular ring region?

Rebecca Sandrone
Posted: 2 years ago Dec 2, 2015, 8:19 PM EST
Hi!

I have the same problem, but my Geometry is set on m. Did anyone solve this issue?

Thanks!
Rebecca
Hi! I have the same problem, but my Geometry is set on m. Did anyone solve this issue? Thanks! Rebecca

Yevgeniy Davletshin
Posted: 2 years ago Dec 3, 2015, 10:53 AM EST
I don't think the bug exists anymore in the latest versions, but I didn't check. what version do you use, geometry and error that you see.
You can always ask support directly they will provide you with answers in 24h time
I don't think the bug exists anymore in the latest versions, but I didn't check. what version do you use, geometry and error that you see. You can always ask support directly they will provide you with answers in 24h time

Rebecca Sandrone
Posted: 2 years ago Mar 7, 2016, 12:11 PM EST
Hi,

I'm using the 5.0 versione, I have a sphere that represents water but I can't define PML since it says that it is not possible to find any spherical geometry. Units are set as meters. What did you do to create PML? you just go in definition, PML, set spherical geometry and the coordinations of the center, right?

Thanks,
Rebecca
Hi, I'm using the 5.0 versione, I have a sphere that represents water but I can't define PML since it says that it is not possible to find any spherical geometry. Units are set as meters. What did you do to create PML? you just go in definition, PML, set spherical geometry and the coordinations of the center, right? Thanks, Rebecca

Walter Frei COMSOL Employee
Posted: 2 years ago Mar 7, 2016, 2:30 PM EST
Dear Rebecca,

For modeling of PML's for wave electromagnetics problems, please see this technical blog:
www.comsol.com/blogs/using-perfectly-matched-layers-and-scattering-boundary-conditions-for-wave-electromagnetics-problems/

Also, please review this example model:
www.comsol.com/model/computing-the-radar-cross-section-of-a-perfectly-conducting-sphere-10332

There are also many other examples of using PML's in the RF Module Application Gallery, available here:
www.comsol.com/models/rf-module?q=pml

For a complete discussion about the various permitted types of PML geometries, please also see the section titled "Infinite Elements and Perfectly Matched Layers" within the COMSOL Multiphysics Reference Manual.

Since this thread originates with an issue in the software that has been addressed for quite some time now, we will close this thread for further comments.

If there are related questions do please first investigate using COMSOL Multiphysics version 5.0 or higher, and please feel free to open a new thread.
Dear Rebecca, For modeling of PML's for wave electromagnetics problems, please see this technical blog: http://www.comsol.com/blogs/using-perfectly-matched-layers-and-scattering-boundary-conditions-for-wave-electromagnetics-problems/ Also, please review this example model: http://www.comsol.com/model/computing-the-radar-cross-section-of-a-perfectly-conducting-sphere-10332 There are also many other examples of using PML's in the RF Module Application Gallery, available here: http://www.comsol.com/models/rf-module?q=pml For a complete discussion about the various permitted types of PML geometries, please also see the section titled "Infinite Elements and Perfectly Matched Layers" within the COMSOL Multiphysics Reference Manual. Since this thread originates with an issue in the software that has been addressed for quite some time now, we will close this thread for further comments. If there are related questions do please first investigate using COMSOL Multiphysics version 5.0 or higher, and please feel free to open a new thread.

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.