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.

Meshing geometries with extreme size difference

Please login with a confirmed email address before reporting spam

I am trying to model an experimental system with bilayer graphene. All the sizes in the system are of the scale of 0.1-10 um, other than the thicknesses, which are about 7nm for the contacts and 1nm for the graphene itself. I keep getting meshing issues about edges and about the graphene layer, and I believe the reason is the extreme size differences. I tried to follow the guidlines from this tutorial but I still get the same errors. Any recommendations on how I can mesh such system? I will also note that the part that interests my for the physics is the graphene itself, while the other materials are mostly there for the boundary values.


2 Replies Last Post 2022年11月14日 GMT-5 09:16
Robert Koslover Certified Consultant

Please login with a confirmed email address before reporting spam

Posted: 2 years ago 2022年11月13日 GMT-5 19:29
Updated: 2 years ago 2022年11月13日 GMT-5 19:30

I encourage you to add interior surfaces or boundaries that have no purpose (no physics on them, other than the by default continuity conditions) other than to divide your problem into multiple, but manageable, adjoining domains. You can then mesh these separately or specify them separately in regard to the sizes of mesh to use in each. Also, consider adjusting the mesh fineness settings. With enough effort, you will succeed in generating an acceptable mesh this way, unless there is something pathologically-wrong with your model. That said, you may or may not be happy with the overall computational-size when you are done, but that is a different question. :)

-------------------
Scientific Applications & Research Associates (SARA) Inc.
www.comsol.com/partners-consultants/certified-consultants/sara
I encourage you to add interior surfaces or boundaries that have no purpose (no physics on them, other than the *by default* continuity conditions) other than to divide your problem into multiple, but manageable, adjoining domains. You can then mesh these separately or specify them separately in regard to the sizes of mesh to use in each. Also, consider adjusting the mesh fineness settings. With enough effort, you *will succeed* in generating an acceptable mesh this way, unless there is something pathologically-wrong with your model. That said, you may or may not be happy with the overall computational-size when you are done, but that is a different question. :)

Jeff Hiller COMSOL Employee

Please login with a confirmed email address before reporting spam

Posted: 2 years ago 2022年11月14日 GMT-5 09:16

Hello Shai,

This blog post on modeling graphene in high frequency electromagnetics should be helpful.

Best regards,

Jeff

-------------------
Jeff Hiller
Hello Shai, [This blog post](https://www.comsol.com/blogs/modeling-graphene-in-high-frequency-electromagnetics/) on modeling graphene in high frequency electromagnetics should be helpful. Best regards, Jeff

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.