Menu

Discussion Forum

New Discussion
Filtern

Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

How to add a constant current boundary?

Posted 07.07.2010, 10:55 GMT-4 4 Replies

Li Zhang
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Hi,

I'm trying to apply a constant current, but I noticed I could only be able to add current density to a boundary. How am I supposed to solve this problem?

Thanks,
Li
4 Replies Last Post 11.07.2010, 00:12 GMT-4
Jie Xiang
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 07.07.2010, 16:34 GMT-4
Maybe you can upload your mph file. I think it is easy to add a surface current density boundary condition in Comsol4.0.
Maybe you can upload your mph file. I think it is easy to add a surface current density boundary condition in Comsol4.0.
Li Zhang
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 07.07.2010, 16:40 GMT-4

Maybe you can upload your mph file. I think it is easy to add a surface current density boundary condition in Comsol4.0.


Hi Jie,

Attached is the model file. Currently I just simply add voltage potential and ground to two terminals. But I would like to add a constant current to the model. I've got no idea how.

Thanks,
Li
[QUOTE] Maybe you can upload your mph file. I think it is easy to add a surface current density boundary condition in Comsol4.0. [/QUOTE] Hi Jie, Attached is the model file. Currently I just simply add voltage potential and ground to two terminals. But I would like to add a constant current to the model. I've got no idea how. Thanks, Li

Attachments:

Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 10.07.2010, 14:10 GMT-4
Hi

I have only my V4.0a available so I cannot read your 3.3 file. But I do not catch the full issue, you you have a conductor surface of lets say 2[mm^2] and you want to force a current of 10[A] then you have a current density of 10/2=5[A/mm^2] no ?

If you impose a voltage you need to adapt it depending on the impedance to get a constant current, though. That is what COMSOL is proposing for the "coil domain" boundary conditions.

You can have COMSOL to caluate the surfaces or the length with the Coupling inte3gration variables (_int of "1")

Good luck
Ivar
Hi I have only my V4.0a available so I cannot read your 3.3 file. But I do not catch the full issue, you you have a conductor surface of lets say 2[mm^2] and you want to force a current of 10[A] then you have a current density of 10/2=5[A/mm^2] no ? If you impose a voltage you need to adapt it depending on the impedance to get a constant current, though. That is what COMSOL is proposing for the "coil domain" boundary conditions. You can have COMSOL to caluate the surfaces or the length with the Coupling inte3gration variables (_int of "1") Good luck Ivar
Li Zhang
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 11.07.2010, 00:12 GMT-4
Thanks, Ivar,

I solved the problem this way.

Li
Thanks, Ivar, I solved the problem this way. Li

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.

Suggested Content