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.

magnetic shielding with mumetal(nonlinear - saturation)

Please login with a confirmed email address before reporting spam

Hi
I need some help with my model....
I have a 3D sim, A current line that generates my field and a mumetal infinite plane(1m*1m*0.5mm)
The 0.5mm is the thickness of my mumetal. I have 0.5T on the surface of the shield and i want to see the B behind the shield.
a.I use relative permeability constant at 7000.
b. I use a non-linear equation with saturation for relative permeability
μr= 1+[(μrmax-1)^(-1) + (μ0*/Η/ / B_sat)^(1/n)] ^(-1)
where mu_rmax=7000, B_sat=0.7T and n=1
c. I use the B-H and H-B curves filling them with my data curves.
Am I correct in any way of these models or I need some refinements to be more precise;
I can see the saturation and the B-H curve; How we can change the scales from a plot in comsol;
Also I attach some photos of my model.
Thanks in advance.


6 Replies Last Post 22.02.2013, 06:05 GMT-5
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 18.02.2013, 10:10 GMT-5
Hi

first of all, isnt it easier to model that as a 2D cut view (independent of Z) with out of plane flow (Z) of the current, in 2D

--
Good luck
Ivar
Hi first of all, isnt it easier to model that as a 2D cut view (independent of Z) with out of plane flow (Z) of the current, in 2D -- Good luck Ivar

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 18.02.2013, 13:35 GMT-5
Hi Ivar, thank you for your reply.
I'll try the 2D cut as you said! I have no problem with the 3D run time sim.
When i use the non linear relation for μr in 3D i receive a n error window....and when i use the BH-HB curve i've got the same result just as the model with μr=const=7000 .
I didn't understand extactly the second part of your saying about the without current flow on z? You mean that when i use the 2D cut this is an option of the geometry?
Thanks again!!
Hi Ivar, thank you for your reply. I'll try the 2D cut as you said! I have no problem with the 3D run time sim. When i use the non linear relation for μr in 3D i receive a n error window....and when i use the BH-HB curve i've got the same result just as the model with μr=const=7000 . I didn't understand extactly the second part of your saying about the without current flow on z? You mean that when i use the 2D cut this is an option of the geometry? Thanks again!!

Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 19.02.2013, 00:54 GMT-5
Hi

Indeed, in 2D you can have current flow along Z the perpendicular direction, or in plane along a combination of X.Y

It's just easier/quicker to debug in 2D, then run a 3D model. For the BH have you checked the Model Library files with saturation iron cases, that gives you the indications how correctly map in the non-linear B-H mode

--
Good luck
Ivar
Hi Indeed, in 2D you can have current flow along Z the perpendicular direction, or in plane along a combination of X.Y It's just easier/quicker to debug in 2D, then run a 3D model. For the BH have you checked the Model Library files with saturation iron cases, that gives you the indications how correctly map in the non-linear B-H mode -- Good luck Ivar

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 19.02.2013, 03:32 GMT-5
Hi Ivar ,

I didn't see all the models at the library but I'll ckeck it out...and I'll inform you about my progress.

Thanks, for your time!
Hi Ivar , I didn't see all the models at the library but I'll ckeck it out...and I'll inform you about my progress. Thanks, for your time!

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 22.02.2013, 04:43 GMT-5
Hello Ivar,
I don't want to bother you but I need your lights.
As far as I understand materials/ACDC modules is your specialty.
I want to upload a model but it is about fluids flow.
I dont know how to do it due to its size(60ΜΒ)...Any ideas??
If you have time and i achieve to upload it, could you check it?You or someone else on this field.
Model :
I want to load a chamber with Argon but inside it i have already air. And I want to see in which way the argon is moving inside the chamber and its concentration. This is a time dependent model, so my last question : Comsol multiphysics counts real time in sec or this is about the time dependent differential equations?
Thanks in advance
Hello Ivar, I don't want to bother you but I need your lights. As far as I understand materials/ACDC modules is your specialty. I want to upload a model but it is about fluids flow. I dont know how to do it due to its size(60ΜΒ)...Any ideas?? If you have time and i achieve to upload it, could you check it?You or someone else on this field. Model : I want to load a chamber with Argon but inside it i have already air. And I want to see in which way the argon is moving inside the chamber and its concentration. This is a time dependent model, so my last question : Comsol multiphysics counts real time in sec or this is about the time dependent differential equations? Thanks in advance

Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 22.02.2013, 06:05 GMT-5
Hi

its far easier to upload models once they are reset :

Edit - clear all solution, clear all mesh, File - reset history then save as with a new name and upload ;)

--
Good luck
Ivar
Hi its far easier to upload models once they are reset : Edit - clear all solution, clear all mesh, File - reset history then save as with a new name and upload ;) -- Good luck Ivar

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.