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.

circular variable dependency detected

Please login with a confirmed email address before reporting spam


Hi,

The author of one paper has defined the conductivity as a function of current density and current density as a function of conductivity. In comsol, it gives a circular dependency error. How to get around it? I would appreciate any suggestion in this regard.

Regards,
Susant

4 Replies Last Post 04.06.2017, 18:56 GMT-4
COMSOL Moderator

Hello Susant Patra

Your Discussion has gone 30 days without a reply. If you still need help with COMSOL and have an on-subscription license, please visit our Support Center for help.

If you do not hold an on-subscription license, you may find an answer in another Discussion or in the Knowledge Base.


Please login with a confirmed email address before reporting spam

Posted: 10 years ago 11.08.2014, 04:20 GMT-4
Hi,
I am having same problem. Have you solved the problem ?

Chandan Kumar
Hi, I am having same problem. Have you solved the problem ? Chandan Kumar

Nagi Elabbasi Facebook Reality Labs

Please login with a confirmed email address before reporting spam

Posted: 10 years ago 11.08.2014, 10:48 GMT-4
There are two ways around this. If you can do some algebraic manipulations you may be able to get the conductivity and current density equations decoupled. If you cannot do that then define a new Domain ODE that breaks that circular dependency. The ODE can just involve one variable that you set equal to the current density and use that new variable in the definition of the conductivity.

Nagi Elabbasi
Veryst Engineering
There are two ways around this. If you can do some algebraic manipulations you may be able to get the conductivity and current density equations decoupled. If you cannot do that then define a new Domain ODE that breaks that circular dependency. The ODE can just involve one variable that you set equal to the current density and use that new variable in the definition of the conductivity. Nagi Elabbasi Veryst Engineering

Please login with a confirmed email address before reporting spam

Posted: 8 years ago 12.06.2016, 03:04 GMT-4
Hi,I am new to COMSOL. I had the same problem. Can you give a simple sample with second method(ODEs)? Thank you very much! My email is njutsjh@163.com.


Jianhua Shao
Hi,I am new to COMSOL. I had the same problem. Can you give a simple sample with second method(ODEs)? Thank you very much! My email is njutsjh@163.com. Jianhua Shao

Please login with a confirmed email address before reporting spam

Posted: 7 years ago 04.06.2017, 18:56 GMT-4
Hi,
I'm implementing a moving mesh in a 2D model with five dependent variables, imposing the 'prescribed deformation' in the domain with 'prescribed mesh displacement' dx = u1x and dy = u1y, but I get the following error message: circular variable dependency detected. Please, could you be more specific about the suggestion in your response of August 11 2014?
Thank you
Hi, I'm implementing a moving mesh in a 2D model with five dependent variables, imposing the 'prescribed deformation' in the domain with 'prescribed mesh displacement' dx = u1x and dy = u1y, but I get the following error message: circular variable dependency detected. Please, could you be more specific about the suggestion in your response of August 11 2014? Thank you

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.