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Error during multiphsics

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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.
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uhyadav

4 Replies Last Post 21.01.2014, 10:49 GMT-5

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Posted: 1 decade ago 09.01.2014, 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

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Posted: 1 decade ago 19.01.2014, 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

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Posted: 1 decade ago 20.01.2014, 08:23 GMT-5

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

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

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Posted: 1 decade ago 21.01.2014, 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?

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