Induced current problem in COMSOL

In summary, the conversation discusses the issues the speaker is facing while using COMSOL's ac-dc module to find the magnetic field created by an electrode pair with nonzero conductivity and relative permittivity. They first tried using the 3D electric module to find the current density between the electrodes and then used this as an external source for the induction (magnetic) module. However, they found that the total current density became almost zero due to the induced current density created by the induction module. The speaker is seeking advice on how to prevent this induced current density. They also mention previously using the quasi static electromagnetic module and trying different boundary conditions, but still getting very small magnetic flux at the boundaries.
  • #1
peagasus
2
0
Hi everyone,

I'm working on COMSOL's ac-dc module and I'm trying to find the magnetic field which is created by an electrode pair (dipole). The working environment of the pair has nonzero conductivity and relative permittivity.

I first found the current density between the electrodes in the 3D electric module and I tried to take the current density value (ie Jx_emqvw) as the external surce of the induction (magnetic) module. Then I started the solver for both electric and magnetic module. However, total current density becomes nearly zero everytime because the induction currents(magnetic) module creates an induced current density equal to the external current density entered by me (ie Jx_emqvw).

What can I do to prevent COMSOL from creating an induced current density?

I would be very glad for your answers.

Regards,

Emin
 
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  • #2
I did use the quasi static electromagnetic module before I tried this, and all the magnetic flux is created at the boundary. I thought that it is not much sense and I decided to try both modules seperately.

Also, I tried two boundaries which I take the smaller one as continuity and the larger one as magnetic insulation with infinite elements. So, the results was nearly the same, very small magnetix flux and at the boundaries.

And I forgot to mention, I thought the induced current that I found in the induction currents module was the reason for creating a very small (~1e-12 and 1e-14) magnetix flux by cancelling the external current density I have entered (ie Jx_emqvw).
 

1. What is an induced current problem in COMSOL?

An induced current problem in COMSOL refers to the phenomenon where an electric current is created in a conductor due to a changing magnetic field. This is based on Faraday's law of electromagnetic induction, which states that a changing magnetic field can induce an electric current in a conductor.

2. How does COMSOL handle induced current problems?

COMSOL uses a finite element method to solve for induced currents. This involves dividing the problem into smaller elements and solving equations at each element to determine the electric and magnetic fields, and subsequently the induced currents.

3. What are the applications of induced current problems in COMSOL?

Induced current problems in COMSOL have various applications in the field of electromagnetics, such as in the design and analysis of transformers, motors, generators, and other devices that utilize electromagnetic induction. It is also used in the simulation of electromagnetic interference and compatibility (EMI/EMC) in electronic circuits and systems.

4. Are there any limitations to using COMSOL for induced current problems?

One limitation of using COMSOL for induced current problems is that it requires a high level of expertise and computational resources. Additionally, COMSOL may not accurately model highly nonlinear materials or extremely complex geometries, so it is important to validate and verify the results with experimental data.

5. Can COMSOL simulate transient induced current problems?

Yes, COMSOL can simulate transient induced current problems. This means that it can model the behavior of induced currents over time, taking into account factors such as the changing magnetic field and the electrical properties of the conductor. This is useful for studying the response of a system to sudden changes in the magnetic field, such as in the case of a lightning strike or a sudden power surge.

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