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 The information provided may be out of date.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.

Error during multiphsics

Please login with a confirmed email address before reporting spam

Hi..
We are try to design saw delay line gas sensor, during the simulation we got error as- Fail to find destination boundaries or destination selection empty please help us to sort out this error.
--
uhyadav

4 Replies Last Post 21 gen 2014, 10:49 GMT-5

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 9 gen 2014, 10:09 GMT-5
Uhyadav:

Uploading the model would be best, but I know when setting up periodic boundary conditions (BCs) this error can occur if COMSOL cannot determine the orientation of the periodicity. For example, setting all four boundaries of a unit cell as periodic under a single BC node--this is wrong, as each boundary pair (the -x/+x faces and -y/+y faces) needs a separate BC implemented.

However, a "gas sensor" model wouldn't seem to need periodic BCs, unless this is a common practice for MEMS. This error also might occur if you are trying to copy a boundary mesh, perhaps? Again, stating more about your error in context with your model will help others better understand your problem.

-Bryan
Uhyadav: Uploading the model would be best, but I know when setting up periodic boundary conditions (BCs) this error can occur if COMSOL cannot determine the orientation of the periodicity. For example, setting all four boundaries of a unit cell as periodic under a single BC node--this is wrong, as each boundary pair (the -x/+x faces and -y/+y faces) needs a separate BC implemented. However, a "gas sensor" model wouldn't seem to need periodic BCs, unless this is a common practice for MEMS. This error also might occur if you are trying to copy a boundary mesh, perhaps? Again, stating more about your error in context with your model will help others better understand your problem. -Bryan

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 19 gen 2014, 06:21 GMT-5

we have confusion in setting the periodic condition and ground in case of saw delay line sensor. please he us.


--
uhyadav
we have confusion in setting the periodic condition and ground in case of saw delay line sensor. please he us. -- uhyadav

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 20 gen 2014, 08:23 GMT-5

we are getting out from BC error, a new error occurs as out of memory in eigenvalue solver.

--
uhyadav
we are getting out from BC error, a new error occurs as out of memory in eigenvalue solver. -- uhyadav

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 21 gen 2014, 10:49 GMT-5
If this is a 3-D model, you may very well be running out of memory. PBCs on a 3-D model require a great deal of memory (mine usually need more than 32GB of physical memory) and special considerations to the meshing. What are your machine specs?
If this is a 3-D model, you may very well be running out of memory. PBCs on a 3-D model require a great deal of memory (mine usually need more than 32GB of physical memory) and special considerations to the meshing. What are your machine specs?

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.