Menu

Discussion Forum

New Discussion
Filter

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 The information provided may be out of date.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.

Parametric Sweep to vary boundary condition type in transient analysis

Posted Jun 5, 2011, 1:52 p.m. EDT Heat Transfer & Phase Change, Modeling Tools & Definitions, Parameters, Variables, & Functions, Studies & Solvers Version 4.1 2 Replies

Sherif Abdelaziz
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Hi,

I am running a thermal transient model within which I would like to change the type of some boundaries between thermal insulation and predefined temperature several times. Doing this manually is quite time consuming and cannot be 100% assured to be error free.

I came across several discussions here in the forum that mentioned that Parametric Sweep can be used to automate this process. None of these discussions have described how can this be done. I am wondering if anyone here have done it and is welling to teach me that. May be a model including this step will help me figure this out.

Thanks
Sherif

p.s. I recently switched to COMSOL 4.1 after using COMSOL 3.5a for the last 3 years so I am not an expert yet with all the tools in COMSOL 4.1
2 Replies Last Post Jun 13, 2011, 11:48 a.m. EDT
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 Jun 6, 2011, 10:42 a.m. EDT
Hi

I believe (but as usual I might be wrong ;) that you will have to write out the equations yourself, as in v4 normally you cannot have two conflicting BC on the same boundary without seeing one override the other.

So this means for me looking at the equations for the two BC and combining them, probably with a weak contraint manually, with a time dependent bolean parameter (perhaps with smmothened transition to avoid spikes and convergence issues)

--
Good luck
Ivar
Hi I believe (but as usual I might be wrong ;) that you will have to write out the equations yourself, as in v4 normally you cannot have two conflicting BC on the same boundary without seeing one override the other. So this means for me looking at the equations for the two BC and combining them, probably with a weak contraint manually, with a time dependent bolean parameter (perhaps with smmothened transition to avoid spikes and convergence issues) -- Good luck Ivar
Sherif Abdelaziz
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Jun 13, 2011, 11:48 a.m. EDT
Hi Ivar,

Thanks for your response to my question.
I just wanted to let you know that I have found a very simple way to vary the type of the boundary condition with time or with any other variable. This way does not depend on using the weak constraint that you proposed which I believe would work but will need a massive amount of work to do it.

My approach is to use COMSOL with MATLAB, using a for loop and conditional statements. It worked perfectly and all my runs now are automated ;)

I just wanted to post this answer for any one else who may have the same question.

Thanks
Sherif
Hi Ivar, Thanks for your response to my question. I just wanted to let you know that I have found a very simple way to vary the type of the boundary condition with time or with any other variable. This way does not depend on using the weak constraint that you proposed which I believe would work but will need a massive amount of work to do it. My approach is to use COMSOL with MATLAB, using a for loop and conditional statements. It worked perfectly and all my runs now are automated ;) I just wanted to post this answer for any one else who may have the same question. Thanks Sherif

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