I'm a beginner in Elmer.
So far, I have tested many cases on the magnetic analysis using Elmer.
But, I failed to get the magnetic forces in 2D Axisymmetric model.
As a example, I have tried it using a double Ccore model with a coil.
In the results, I got force(1,2,3) = 6.562606332450E+001 1.881623416445E+003 0.000000000000E+000.
Results of FEMM(another 2D FEM solver) are 0 67.3566 0.
I attach the sif and mesh file.
Please inform me on what is wrong.
incorrect magnetic force in 2D axisymmetric magnetic model

 Posts: 4
 Joined: 24 Apr 2018, 03:33
 Antispam: Yes

 Posts: 4
 Joined: 24 Apr 2018, 03:33
 Antispam: Yes
Re: incorrect magnetic force in 2D axisymmetric magnetic model
Also, the distributed patterns of Vector potential line are different in FEMM and Elmer(using Paraview) as followings.
[Elmer <Paraview>] [FEMM]
Why different ????
[Elmer <Paraview>] [FEMM]
Why different ????
Re: incorrect magnetic force in 2D axisymmetric magnetic model
Hi,
it seems like one of the solvers makes a mistake here, or both have not been fed with the same input parameters.
If I were you, I would sit back and try to find out what would be the expected physical result. I don't see it right away, and I don't have the time right now to think about it and look into my electromagnetics textbook...
Maybe you could build a simpler geometry where the result can be calculated analytically?
HTH,
Matthias
it seems like one of the solvers makes a mistake here, or both have not been fed with the same input parameters.
If I were you, I would sit back and try to find out what would be the expected physical result. I don't see it right away, and I don't have the time right now to think about it and look into my electromagnetics textbook...
Maybe you could build a simpler geometry where the result can be calculated analytically?
HTH,
Matthias
Re: incorrect magnetic force in 2D axisymmetric magnetic model
Hi,
have you tried increasing
Steady State Max Iterations?
BR, Pavel
have you tried increasing
Steady State Max Iterations?
BR, Pavel
Re: incorrect magnetic force in 2D axisymmetric magnetic model
Note that in case you have an axisymmetric case, in Paraview, you need to multiply the vector potential with 2 * pi * r if you wish to plot the magnetic field lines.Yeonho Jeong wrote:Also, the distributed patterns of Vector potential line are different in FEMM and Elmer(using Paraview) as followings.
Why different ????
So you should take the contour plot from a new variable "a_cont = 2 * pi * coordsX* a" (this you can compute with the Calculator in Paraview). Look at the attached countour plot.

 Posts: 4
 Joined: 24 Apr 2018, 03:33
 Antispam: Yes
Re: incorrect magnetic force in 2D axisymmetric magnetic model
Thank you, Takala !
It works fine in plotting the magnetic field line.
And, I didn't still solve the incorrect magnetic force problem in 2D axisymmetric analysis,
on why the rcomponent of magnetic force have a big value.
It works fine in plotting the magnetic field line.
And, I didn't still solve the incorrect magnetic force problem in 2D axisymmetric analysis,
on why the rcomponent of magnetic force have a big value.