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 The information provided may be out of date.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.
How to solve an eigenvalue problem?
Posted 2011年9月9日 GMT-4 11:05 Studies & Solvers Version 4.2 1 Reply
Please login with a confirmed email address before reporting spam
This is my first time to use COMSOL. I want to solve an eigenvalue problem on a geometry : a unit square with a circle inside. I attached file.
div ( ep^(-1)* grad u)=lambda * u
where ep =1 outside the circle and ep=(1-lambda^(-1))^(-1) inside circle ,
u is continuous on the interior boundary (the boundary of circle) , and
n (ep * grad u) |_outside = n (ep* grad u) |_inside on the interior boundary.
on the boundary of the square,
u is periodic on the up and down sides, and is Floquet periodic on the left and right sides, i.e., u(x_left)=u(x_right)*exp^(i*k), k is a specific real number, for example k=1.
My questions are
1) how to set the interior boundary condition?
2) it is a nonlinear eigenvalue problem. I don't know if the software can solve it. Because it always gives me the error message : undefined value found.
3) how to set the Floquet boundary condition?
Sorry for so many problems. But it really bothered me a lot.
I am using 4.2 version. Please check my attachment.
Thanks a lot.
Yue
Attachments:
Hello Yue Chen
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.
Please login with a confirmed email address before reporting spam
Did you solve the problem of applying floquet boundary condition?
Thanks.