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Magnetic Field of a Multi Layer solenoid

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Hello Everyone,

I have no experience in using COMSOl.

My professor wants me to run an example project in this software and I have a few specific questions.
The problem statement is:
I have a multi layer coil. Each layer has 10 wounds and there are 5 layers. The coil is wound on a ceramic rod. I need to give AC current as an input and plot the magnetic field distribution around the coil. ( more importantly along the axis of the rod).
How I proceeded
I designed the coil in SOLIDWORKS and imported the file into COMSOL. I designed an cubical test area around the coil (infinite element domain). I specified material for coil as copper and for the test area as air.
What should be the selection in Ampere's law?
I included coil ends and the sidesof test area cube in magnetic insulation.
Then I chose Single turn coil and gave boundary feed (How can I input AC current?) to one end and ground to another.
I chose a fine mesh size and meshed the coil using free tetrahedral. For the test area I chose free triangular.
I input 10 kHz as the frequency.
I don't see any fancy plots coming up. All it shows is 0 and faint green
Can someone tell me where I am going wrong? How do I proceed further?

Thanks in advance,
Rahul Korpu


5 Replies Last Post Aug 23, 2015, 3:37 p.m. EDT

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Posted: 9 years ago Jun 18, 2015, 2:23 p.m. EDT
I am not able to upload the file because the site says file size error. The file is only 16 mb.
Also when I am trying to open the file on an other computer, it says file is locked. I didn't lock anything.
I am not able to upload the file because the site says file size error. The file is only 16 mb. Also when I am trying to open the file on an other computer, it says file is locked. I didn't lock anything.

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Posted: 9 years ago Aug 19, 2015, 4:52 a.m. EDT
hey rahul,
how did you design a multi layer coil?

hey rahul, how did you design a multi layer coil?

Mahesh MS by Research

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Posted: 9 years ago Aug 21, 2015, 6:06 a.m. EDT
It's rather easy solving a multilayer coil to be designed in the COMSOL GUI itself rather than doing it in a mechanical software and then importing it.
Kindly look into the attachment for how to model single and multi layer coil.
copy.com/PML9kKsU8rKxKKDn

Regards
Mahesh
It's rather easy solving a multilayer coil to be designed in the COMSOL GUI itself rather than doing it in a mechanical software and then importing it. Kindly look into the attachment for how to model single and multi layer coil. https://copy.com/PML9kKsU8rKxKKDn Regards Mahesh


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Posted: 9 years ago Aug 22, 2015, 11:57 a.m. EDT
hello mahesh,
I try to apply a streamline 3 D plot to the multi coil circular model and plot the coil direction but i don't get any plot. i can't seem to understand why though. could you please help me out there.

I am basically trying to find out the lorentz force on a magnet due to a rectangular coil in front of it.
I built a rectangular coil using the numeric option. then i set up a magnet perpendicular to it.

i have used two physics, one MF for the coil and the other MFNC for the magnet.

I used two studies, study one had current calculation and stationary, study two includes current calc and frequency domain.

problems i face:
1) i don't know why i cant give an output. i can give an input for a boundary but all other boundaries say inapplicable.
2) i donot know how to apply lorentz force.
3) i cannot upload my model. it says file size error.

Thanks in advance
hello mahesh, I try to apply a streamline 3 D plot to the multi coil circular model and plot the coil direction but i don't get any plot. i can't seem to understand why though. could you please help me out there. I am basically trying to find out the lorentz force on a magnet due to a rectangular coil in front of it. I built a rectangular coil using the numeric option. then i set up a magnet perpendicular to it. i have used two physics, one MF for the coil and the other MFNC for the magnet. I used two studies, study one had current calculation and stationary, study two includes current calc and frequency domain. problems i face: 1) i don't know why i cant give an output. i can give an input for a boundary but all other boundaries say inapplicable. 2) i donot know how to apply lorentz force. 3) i cannot upload my model. it says file size error. Thanks in advance

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

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Posted: 9 years ago Aug 23, 2015, 3:37 p.m. EDT
Hi

I suspect your problem comes from the fact that you use two magnetic physics, one is enough, in your case. I would use MF and then define your magnet as an extra linear magnetic domain with a Magnetisation setting for the fixed magnet.

To read-out forces you need to define the Force Domain Conditions to the magnet

and to upload files, start to "clean" them to reduce their size by a "Solver Clear All", "Mesh Clear All" and then "File Compact Model" then save as and export the new file. We can always rerun the mesher and the solver, and your file will be "small" and easy to handle

To get used to the different ACDC settings, I can only recommend to start with some models in the Model/Application library, print out the PDF and construct the models step by step, you will then better understand the logic, especially when you begin (even after a decade with COMSOL" I do this for new domains or physics I have not used for some time, and after new releases as there are many subtle changes one learn like that)

--
Good luck
Ivar
Hi I suspect your problem comes from the fact that you use two magnetic physics, one is enough, in your case. I would use MF and then define your magnet as an extra linear magnetic domain with a Magnetisation setting for the fixed magnet. To read-out forces you need to define the Force Domain Conditions to the magnet and to upload files, start to "clean" them to reduce their size by a "Solver Clear All", "Mesh Clear All" and then "File Compact Model" then save as and export the new file. We can always rerun the mesher and the solver, and your file will be "small" and easy to handle To get used to the different ACDC settings, I can only recommend to start with some models in the Model/Application library, print out the PDF and construct the models step by step, you will then better understand the logic, especially when you begin (even after a decade with COMSOL" I do this for new domains or physics I have not used for some time, and after new releases as there are many subtle changes one learn like that) -- Good luck Ivar

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