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.

Basic capacitance simulation: non physical variation of results with minor modification of mesh

Please login with a confirmed email address before reporting spam

Hi all,

I am trying to simulate capacitance between two electrodes with the electrostatics module of Comsol 4.2a using a model succinctly described in the attached picture.

I want later to investigate the influence of a "trench" (rectangle R in the picture) in material 2, i.e. the rectangle R will have the properties of material 1.

Before doing this, I checked what happen when I insert the rectangle R in the model but still apply the properties of material 2 to it. And here comes the unphysical results: the predicted capacitance value vary (quite importantly) with the height d of the rectangle R. This does not make sense from a physical point of view . I understand that the mesh is modified each time that the value of d is changed and that this discrepancy may be related to that. But this is very annoying to me as I feel that I will not be able to make the difference between numerical artifacts and real capacitance variation when I will investigate the influence of trenches in material 2.

Any suggestion to solve this issue would be appreciated.

Thanks


2 Replies Last Post 2012年4月13日 GMT-4 10:27

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 2012年4月13日 GMT-4 05:37
Hi Michael Renaud,
The answer is in your question, I think that maybe you will use Moving Mesh (ALE) application mode to make a frame to allow the mesh to move. Can you attach your model to take a look.


I understand that the mesh is modified each time that the value of d is changed and that this discrepancy may be related to that.


Hi Michael Renaud, The answer is in your question, I think that maybe you will use Moving Mesh (ALE) application mode to make a frame to allow the mesh to move. Can you attach your model to take a look. [QUOTE] I understand that the mesh is modified each time that the value of d is changed and that this discrepancy may be related to that. [/QUOTE]

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 2012年4月13日 GMT-4 10:27
Thanks for your answer Amine.
I found the problem: what made the mess was just the "infinite" elements that I used in my model. If I replace them by large surface without the "infinite" property, I do not observe the problem mentioned before.
Thanks for your answer Amine. I found the problem: what made the mess was just the "infinite" elements that I used in my model. If I replace them by large surface without the "infinite" property, I do not observe the problem mentioned before.

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.