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relative permeability as a function of mf.Hz and solid.sz

Posted Feb 16, 2011, 12:55 a.m. EST Materials, Modeling Tools & Definitions, Parameters, Variables, & Functions, Studies & Solvers Version 4.0, Version 4.2a 4 Replies

Behrooz Rezaeealam
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Hi
I am trying to define the relative permeability as a function of mf.Hz and solid.sz ( magnetic and structure application modes) using interpolation function as sectionwise file and calling it for example:
hsmu11=hsmu(mf.Hz[m/A],solid.sz[m^2/N])
However I face an error like this:

Circular variable dependency detected.
- Variable: mod1.hsmu11
- Geometry: 1
- Domain: 3

also i was wondering if i am suppoed to define the sequence of solutions for the two application modes, or it is considered automatically by itself, (for stationary case)

I would be grateful if you help me
Behrooz
4 Replies Last Post Apr 11, 2012, 6:34 p.m. EDT
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
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Posted: 1 decade ago Feb 16, 2011, 1:49 a.m. EST
Hi

Indeed I would say that you must find a way to cut the circular reference: i.e to manually add a segregated solver sequence in your solution node

--
Good luck
Ivar
Hi Indeed I would say that you must find a way to cut the circular reference: i.e to manually add a segregated solver sequence in your solution node -- Good luck Ivar
Gordon Freeman
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Posted: 1 decade ago Feb 21, 2011, 8:22 a.m. EST

Hi
I am trying to define the relative permeability as a function of mf.Hz and solid.sz ( magnetic and structure application modes) using interpolation function as sectionwise file and calling it for example:
hsmu11=hsmu(mf.Hz[m/A],solid.sz[m^2/N])
However I face an error like this:

Circular variable dependency detected.
- Variable: mod1.hsmu11
- Geometry: 1
- Domain: 3

also i was wondering if i am suppoed to define the sequence of solutions for the two application modes, or it is considered automatically by itself, (for stationary case)

I would be grateful if you help me
Behrooz


Hello !

We have thermo-magnetic problem, and we have to define relative permeability depends on temperature and magnetic field (mur(T,H)), but we don't know how input this data.
Can you give us file with data for sectionwise interpolation ? We have the same problem and this examples would very usefull for us...

Thanks.
[QUOTE] Hi I am trying to define the relative permeability as a function of mf.Hz and solid.sz ( magnetic and structure application modes) using interpolation function as sectionwise file and calling it for example: hsmu11=hsmu(mf.Hz[m/A],solid.sz[m^2/N]) However I face an error like this: Circular variable dependency detected. - Variable: mod1.hsmu11 - Geometry: 1 - Domain: 3 also i was wondering if i am suppoed to define the sequence of solutions for the two application modes, or it is considered automatically by itself, (for stationary case) I would be grateful if you help me Behrooz [/QUOTE] Hello ! We have thermo-magnetic problem, and we have to define relative permeability depends on temperature and magnetic field (mur(T,H)), but we don't know how input this data. Can you give us file with data for sectionwise interpolation ? We have the same problem and this examples would very usefull for us... Thanks.
Behrooz Rezaeealam
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Posted: 1 decade ago Feb 21, 2011, 6:56 p.m. EST
hello
i dont have a solved example untill now,
for sectionwise file format, you can find it inside the help,
the problem is the error of circular variable dependency, that can not be solved only by segregated steps, and actually you must know the formulation inside comsol to understand which parameter is accepted as an input, for example there is a problem with MUR(H,T), but probably there is no prblem with MUR(B,T),
H=magnetic intensity
B=flux density
good luck
behrooz
hello i dont have a solved example untill now, for sectionwise file format, you can find it inside the help, the problem is the error of circular variable dependency, that can not be solved only by segregated steps, and actually you must know the formulation inside comsol to understand which parameter is accepted as an input, for example there is a problem with MUR(H,T), but probably there is no prblem with MUR(B,T), H=magnetic intensity B=flux density good luck behrooz
Giti Karimi
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Posted: 1 decade ago Apr 11, 2012, 6:34 p.m. EDT
Hi Gordon,
I work on thermo-magnetic too. Could you solve your problem which you mentioned here? I have the same problem. I have sent this e-mail for COMSOL support, and waiting for their reply;

Hello,
I need to define magnetization in the field as a function of magnetic field and temperature. I mean M=M(H,T). Since I have coupled "magnetic fields(mf)" and "Non-isothermal flow (nitf)", I don't have any problem with T, but it seems that I can not use H inside the "magnetic fields(mf)" module. I've got error as "Circular variable dependency detected", but I really need to do this. I would be so thankful if you can help me to know how I should do it.
Thank you in advance,

Regards,
Giti
Hi Gordon, I work on thermo-magnetic too. Could you solve your problem which you mentioned here? I have the same problem. I have sent this e-mail for COMSOL support, and waiting for their reply; Hello, I need to define magnetization in the field as a function of magnetic field and temperature. I mean M=M(H,T). Since I have coupled "magnetic fields(mf)" and "Non-isothermal flow (nitf)", I don't have any problem with T, but it seems that I can not use H inside the "magnetic fields(mf)" module. I've got error as "Circular variable dependency detected", but I really need to do this. I would be so thankful if you can help me to know how I should do it. Thank you in advance, Regards, Giti

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