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Magnetic Field Magnet Bar

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Hello everybody,

I am new to Comsol and my goal is to model the magnetic field/field line(/force on a object). It seems to me that this is a simple problem for professionals but I have my problems.

As a guidance I used a tutorial (www.comsol.de/blogs/quick-intro-permanent-magnet-modeling/).

What I did...
- New 3D "Magnetic Fields, No current" project
- 2 Blocks attached to each other :
blk1 : 20x5x5 at (-10/0/-2.5)
blk2: 20x5x5 at (-10/-5/-2.5)
- 1 Block for surrounding air
blk3: 40x40x40 at (-20/-20/-20)
- Compose I : Booleans and Partitions: Compose : Input objects : blk1 blk 2 blk3
Formula: blk3+blk1*blk3+blk2*blk3
- Define 2 materials(blank material): Air (blk3, Relative Permeability Value=1) and Iron (blk1, Value=4000)
- Magnetic Flux Conservation for Domain 2 ; Consitutive Relation - Magnetization - M_x 750000 A/m

And here I got stuck. What to do next? What else is missing?
I can add the mesh and specify how fine they are but I get an error running the model.

I appreciate your help.

Kind regards



1 Reply Last Post Mar 13, 2015, 7:25 a.m. EDT

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Posted: 10 years ago Mar 13, 2015, 7:25 a.m. EDT
I also tried to follow this: www.comsol.com/community/forums/general/thread/33304/

Here I manage two create the two blocks and the settings.
When I compute and have a look at the streamlines plot it seems a bit wired.

I just put a block 10x4x4 in the middle and air around it. The smaller block which schould be the magnet is assigned with 750000kA/m.

I also tried to add a second block to plot two bar magnets streamlines but it also doen't look right.

What am I doing wrong?
I also tried to follow this: http://www.comsol.com/community/forums/general/thread/33304/ Here I manage two create the two blocks and the settings. When I compute and have a look at the streamlines plot it seems a bit wired. I just put a block 10x4x4 in the middle and air around it. The smaller block which schould be the magnet is assigned with 750000kA/m. I also tried to add a second block to plot two bar magnets streamlines but it also doen't look right. What am I doing wrong?

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