Note: This discussion is about an older version of the COMSOL Multiphysics® software. The information provided may be out of date.
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.
Temperature dependent variables - Circular variable dependency detected.
Posted 18 mai 2011, 12:24 UTC−4 Parameters, Variables, & Functions Version 4.1 3 Replies
Please login with a confirmed email address before reporting spam
I would like to define some temperature-dependent variables in my model. I defined them under "Global definitions - variables". So Comsol shall calculate for each time step the variable with the current temperature.
For example:
Name: E
Expression: 500*T - 200 [Pa]
I thought, that Comsol know that he has to use the temperature for "T", but I got an error message:
Circular variable dependency detected.
- Variable: T
- Geometry: 1
- Domain: 1
Can anyone help me?
Greetings.
Please login with a confirmed email address before reporting spam
Try this:
(500*mod1.T[1/K]-200)[Pa]
[1/K] is there to cancel the units of temperature.
Please login with a confirmed email address before reporting spam
Please login with a confirmed email address before reporting spam
Since you are defining a global variable, you should point to the model to which it belongs. In your case, T is the dependent variable for model 1 (your only model I presume), that is why calling this variable requires: mod1.T, where mod1 is your model's identifier.
If the same variable is used in a subdomain field (variables under model 1), you could ommit the pointer mod1 and just use the variable T
Regards
--
Ali