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.

Sweep with a dummy parameter

Please login with a confirmed email address before reporting spam

Hi all,
something a bit disturbing happened to me recently. A set up a "surface-to-surface radiation" model and wanted to study the dependence of the solution on the position of a geometric feature. So I defined a parameter "offset" and set up a study with a parametric sweep on that parameter. I found a very clear dependence, with a variation of as much as 5% between the solutions. Surprised a bit from the result, I went back to the model definition to double check things, when i realized that I never put that parameter in the geometry definition. So, despite being defined in the parameters list and being swept on by the solver, that parameter should have changed absolutely nothing in the model. Instead, it does... and in a way that can be easily confused with a real functional dependence.

Now, you will all understand that if the solution of a parametric sweep shows a dependence from a parameter that does appear in the model, it become a bit hard to trust it for a study on the dependence on a parameter that indeed appears in the model...

Have anyone experienced a similar occurrence? Any ideas?

I'm attaching the model file if you are interested in having a look... use the 1D plot groups to compare the various solutions...

Giacomo


0 Replies Last Post 2 juil. 2012, 10:14 UTC−4
COMSOL Moderator

Hello Giacomo Ciani

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.

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.