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Magnetic Fields Lower Than Expected

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Hello, I have been simulating the magnetic field for a Hall Effect thruster but I am getting much lower mangnetic field strengths in the channel than I am expecting. Is there a reason for this? Also if I run an axisymmetric design which is similar in FEMM then I get a magentic field strength which is ten times greater than COMSOL is giving me. Why would this be, I belive I have set the simulations up with the same properties and everything.

Thank you Hazel


2 Replies Last Post 12 févr. 2021, 09:54 UTC−5
Robert Koslover Certified Consultant

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Posted: 4 years ago 8 févr. 2021, 11:00 UTC−5
Updated: 4 years ago 8 févr. 2021, 11:04 UTC−5

There are too many possibilities. Since you seem to have these two separate computational tools available, I suggest you model (with both codes) something otherewise similar, but where you already know the answer beforehand to good accuracy (e.g., to better than a factor of 2). Then you can at least decide which (if either) code is correct. When answers differ by a factor of ten, it is often (not always) easy to identify one that is simply wrong. If/when you decide that the Comsol model is the one with the wrong answer, then I encourage you to post your model to the forum, so it can be examined by others here in detail.

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Scientific Applications & Research Associates (SARA) Inc.
www.comsol.com/partners-consultants/certified-consultants/sara
There are too many possibilities. Since you seem to have these two separate computational tools available, I suggest you model (with both codes) something otherewise similar, but where you already *know* the answer beforehand to good accuracy (e.g., to better than a factor of 2). Then you can at least decide which (if either) code is correct. When answers differ by a factor of ten, it is *often* (not always) easy to identify one that is simply wrong. If/when you decide that the Comsol model is the one with the wrong answer, then I encourage you to post your model to the forum, so it can be examined by others here in detail.

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Posted: 4 years ago 12 févr. 2021, 09:54 UTC−5

I belive that it is the COMSOL model which is giving me the incorrect values, and so have attched an inital simulation with five coils as an example.

I belive that it is the COMSOL model which is giving me the incorrect values, and so have attched an inital simulation with five coils as an example.

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