Small air gap boundary condition

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I am simulating some induced eddy currents in a copper plate suspended above an alternating magnetic dipole (10 kHz). I want to split the copper plate into two halves and apply a boundary condition (or equivalent) between the two halves which simulates the copper plates not quite touching and prevents current from flowing across/normal to the boundary condition.

I have had success by creating a physical air gap between the plates (you can see the thin domain along the center of the plate which I have been setting as air material), but not by setting a boundary condition.

In my model at the moment I have a 'Magnetic Insulation 2' boundary condition which I am hoping to replace for another which will give me the desired properties.

What is best practice for simulating small air gaps like this specifically to prevent eddy current flow?



4 Replies Last Post 07.10.2024, 04:27 GMT-4

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Posted: 4 days ago 03.10.2024, 04:11 GMT-4

Surely you just need to assign Air to domain 7? A magnetic insulation BC is not representative of the physical situation you are trying to re-create.

Surely you just need to assign Air to domain 7? A magnetic insulation BC is not representative of the physical situation you are trying to re-create.

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Posted: 4 days ago 03.10.2024, 07:37 GMT-4

Surely you just need to assign Air to domain 7? A magnetic insulation BC is not representative of the physical situation you are trying to re-create.

Hi Mark, cheers for the feedback. Yes the magnetic insulation BC is what I wanted to replace with something that IS representative ( I just had it in there as a leftover failed attempt ). As I mentioned I have tried assigning the central domain 7 to air and achieved good results.

I should have said: I am using this model as a simplified case of a larger more complex one. The air gaps in the larger model are orders of magnitude thinner than domain 7 and I don't think it is best practice to mesh this?

There must be a condition that I can impose on the boundary between the two halves of the plate which provides the same impedance (or equivalent) that a 0.01 mm air gap would? Will it require linking a different physics module into the magnetic fields module such as the Electric Currents module?

>Surely you just need to assign Air to domain 7? A magnetic insulation BC is not representative of the physical situation you are trying to re-create. Hi Mark, cheers for the feedback. Yes the magnetic insulation BC is what I wanted to replace with something that IS representative ( I just had it in there as a leftover failed attempt ). As I mentioned I have tried assigning the central domain 7 to air and achieved good results. I should have said: I am using this model as a simplified case of a larger more complex one. The air gaps in the larger model are orders of magnitude thinner than domain 7 and I don't think it is best practice to mesh this? There must be a condition that I can impose on the boundary between the two halves of the plate which provides the same impedance (or equivalent) that a 0.01 mm air gap would? Will it require linking a different physics module into the magnetic fields module such as the Electric Currents module?

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Posted: 7 hours ago 07.10.2024, 03:05 GMT-4

Surely you just need to assign Air to domain 7? A magnetic insulation BC is not representative of the physical situation you are trying to re-create.

Good point! Assigning a gas to Domain 7 makes sense to more accurately represent the physical environment. The use of magnetic insulators may cause inaccurate results. This is because they do not reflect behavior in the real world.

>Surely you just need to assign Air to domain 7? A magnetic insulation BC is not representative of the physical situation you are trying to re-create. Good point! Assigning a gas to Domain 7 makes sense to more accurately represent the physical environment. The use of magnetic insulators may cause inaccurate results. This is because they do not reflect behavior in the real world.

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Posted: 6 hours ago 07.10.2024, 04:27 GMT-4

Surely you just need to assign Air to domain 7? A magnetic insulation BC is not representative of the physical situation you are trying to re-create.

Good point! Assigning a gas to Domain 7 makes sense to more accurately represent the physical environment. The use of magnetic insulators may cause inaccurate results. This is because they do not reflect behavior in the real world.

Hi Joshua, as i have explained I am aware that that the magnetic insulator BC is wrong in this case and I am also aware that assigning a gas to domain 7 yields good results.

I want to know if I can apply constraints to the boundary between the two halves of the plate, not domain 7, which will have the same affect as assigning air to domain 7.

>>Surely you just need to assign Air to domain 7? A magnetic insulation BC is not representative of the physical situation you are trying to re-create. > >Good point! Assigning a gas to Domain 7 makes sense to more accurately represent the physical environment. The use of magnetic insulators may cause inaccurate results. This is because they do not reflect behavior in the real world. Hi Joshua, as i have explained I am aware that that the magnetic insulator BC is wrong in this case and I am also aware that assigning a gas to domain 7 yields good results. I want to know if I can apply constraints to the **boundary** between the two halves of the plate, not domain 7, which will have the same affect as assigning air to domain 7.

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