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Bug in Subdomain setting??
Posted 12 gen 2012, 23:09 GMT-5 3 Replies
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Hi everyone,
I would like to design a device which works in air. As the attached pdf file shows, the second largest rectangular contains the whole assembled device, the gap between this and the biggest rectangular is air. I would like to assign refractive index to different elements of the device and working environment. But the air region can not be independently selected, as shown in the pdf file. In the inner rectangular, the refractive index of media is periodically modified, and the value is other than one.
Moreover, I can not apply continuity boundary condition with in the device. I have checked that there is no air gap within the device.
This is really confusing, thank you for your help..
Ferris
I would like to design a device which works in air. As the attached pdf file shows, the second largest rectangular contains the whole assembled device, the gap between this and the biggest rectangular is air. I would like to assign refractive index to different elements of the device and working environment. But the air region can not be independently selected, as shown in the pdf file. In the inner rectangular, the refractive index of media is periodically modified, and the value is other than one.
Moreover, I can not apply continuity boundary condition with in the device. I have checked that there is no air gap within the device.
This is really confusing, thank you for your help..
Ferris
Attachments:
3 Replies Last Post 13 gen 2012, 11:41 GMT-5
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Posted:
1 decade ago
Hi
probably you have something wrong in your geoemtry, as if you have a set of overlapping rectangles your (sub)domain should be divided into many elements, and COMSOL applies by default "continuity" to the interiour boundaries. Then you can apply different indexes to the different layers.
If you made your geoemtry by a rectangle and several lines, you might ned to combine it into a "solid" first, and to be sure the lines intersect correctly
--
Good luck
Ivar
probably you have something wrong in your geoemtry, as if you have a set of overlapping rectangles your (sub)domain should be divided into many elements, and COMSOL applies by default "continuity" to the interiour boundaries. Then you can apply different indexes to the different layers.
If you made your geoemtry by a rectangle and several lines, you might ned to combine it into a "solid" first, and to be sure the lines intersect correctly
--
Good luck
Ivar
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Posted:
1 decade ago
Hi Ivar,
Thank you for your response.
The structure is assembled by ten units, with cladding materials at top and bottom. As a whole, it is a series of quantum wells. Since in one unit, one piece material is only 2 nanometers thick, the other has a thickness of 40nm. Therefore, it looks like the structure is not arranged perfectly without zooming in. Actually, I have zoom in the structure, and I attached the zoomed in sample. I am pretty sure that the arrangement is perfect.
As you said, the default boundary conditions for the inner media is continuity. Right now, the situation is so confusing to me.
I am not sure if there are some other factors which will result in the bug in my simulation?
Thanks
Ferris
Thank you for your response.
The structure is assembled by ten units, with cladding materials at top and bottom. As a whole, it is a series of quantum wells. Since in one unit, one piece material is only 2 nanometers thick, the other has a thickness of 40nm. Therefore, it looks like the structure is not arranged perfectly without zooming in. Actually, I have zoom in the structure, and I attached the zoomed in sample. I am pretty sure that the arrangement is perfect.
As you said, the default boundary conditions for the inner media is continuity. Right now, the situation is so confusing to me.
I am not sure if there are some other factors which will result in the bug in my simulation?
Thanks
Ferris
Attachments:
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Posted:
1 decade ago
Hi
do not forget to adjust the absolute and/or relative tolerances of the geometry for such small features
--
Good luck
Ivar
do not forget to adjust the absolute and/or relative tolerances of the geometry for such small features
--
Good luck
Ivar