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defining a no-flux 2D surface on top of a 3D box

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hi Everyone,

i'm qiute novice to comsol and have the following problem:

i need to to visualize diffusion in a 3D box made of GaAs that has a round mask on its top surface. now i know that i can just create a 3D thin mask of say Titanium, mesh it, have flux on the whole thing and solve. i was thinking though of not wasting mesh on a structure that its only purpose is to create a no-flux surface underneath it. so i was thinking to create a no-flux 2D round surface on top of the top surface of the GaAs box but couldnt figure out the way to do it. please help

10 Replies Last Post Mar 1, 2017, 1:18 p.m. EST
Jeff Hiller COMSOL Employee

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Posted: 7 years ago Feb 24, 2017, 12:05 p.m. EST
Hello Saeed,
Is the box a parallelepiped?
If so, you can simply draw a disc in a workplane that coincides with the surface of the box.
If the box has a complex shape, see my last post in this thread: www.comsol.com/community/forums/general/thread/15263
Best,
Jeff
Hello Saeed, Is the box a parallelepiped? If so, you can simply draw a disc in a workplane that coincides with the surface of the box. If the box has a complex shape, see my last post in this thread: https://www.comsol.com/community/forums/general/thread/15263 Best, Jeff

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Posted: 7 years ago Feb 24, 2017, 12:19 p.m. EST
hi,

the box is a simple box (parallelpiped) but how can i create a workplane?
hi, the box is a simple box (parallelpiped) but how can i create a workplane?

Jeff Hiller COMSOL Employee

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Posted: 7 years ago Feb 24, 2017, 12:22 p.m. EST
You just right-click on the Geometry node and select Workplane. Same as other geometry operations, basically.
Jeff
You just right-click on the Geometry node and select Workplane. Same as other geometry operations, basically. Jeff

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Posted: 7 years ago Feb 24, 2017, 12:47 p.m. EST
done so, and draw a circle, but i cannot see the circle when i am looking at my 3D geometry, is that the way it should be?
done so, and draw a circle, but i cannot see the circle when i am looking at my 3D geometry, is that the way it should be?

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Posted: 7 years ago Feb 24, 2017, 12:51 p.m. EST
ok ok.... i needed to tick somewhere, now i see the circle

ok, now how i define the flux and no-flux fields so that i dont mess things up?
ok ok.... i needed to tick somewhere, now i see the circle ok, now how i define the flux and no-flux fields so that i dont mess things up?

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Posted: 7 years ago Feb 24, 2017, 12:53 p.m. EST
sorry again ... did it on my own ... wow !!
sorry again ... did it on my own ... wow !!

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Posted: 7 years ago Feb 24, 2017, 1:27 p.m. EST
thnx for the help, still far from completing the model so i will keep annoying people here for a while :)

regards,
saeed
thnx for the help, still far from completing the model so i will keep annoying people here for a while :) regards, saeed

Jeff Hiller COMSOL Employee

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Posted: 7 years ago Feb 24, 2017, 4:31 p.m. EST
Glad to hear you are making progress, Saeed.
To get acquainted with the graphical user interface, I recommend reviewing and working through the tutorials contained in the Introduction to COMSOL Multiphysics manual, version 5.2a, available here: cdn.comsol.com/documentation/5.2.1.262/IntroductionToCOMSOLMultiphysics.pdf and inside the software under File > Help > Documentation.

Best,
Jeff
Glad to hear you are making progress, Saeed. To get acquainted with the graphical user interface, I recommend reviewing and working through the tutorials contained in the Introduction to COMSOL Multiphysics manual, version 5.2a, available here: https://cdn.comsol.com/documentation/5.2.1.262/IntroductionToCOMSOLMultiphysics.pdf and inside the software under File > Help > Documentation. Best, Jeff

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Posted: 7 years ago Mar 1, 2017, 1:10 p.m. EST
hi again,

how can i attach a COMSOL file? the system does not allow me to
hi again, how can i attach a COMSOL file? the system does not allow me to

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Posted: 7 years ago Mar 1, 2017, 1:18 p.m. EST
i saw that Jeff posted an mph file, how that can be done? the system gives me an error saying that the file extension is not legitimate
i saw that Jeff posted an mph file, how that can be done? the system gives me an error saying that the file extension is not legitimate

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