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Greetings! Question regarding Heating Tissue with Magnets via particles inside said tissue (2D, 4.0a)

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Greetings COMSOL users!

I have just started my endeavours with COMSOL 4.0 in 2D, and after reading some very interesting documents, examples and articles I consider hitting a wall to which I require some assistance.

My model aims at studying the influences a nearby magnet can have on tissue if we have several randomly distributed particles that are influenced (if any) by the magnetic field of said magnet.

So far I believe that I set up the model correctly with the use of the physics Magnetic, No Currents - I have a magnet, and a square nearby in which I have some circles of various dimensions and distance - I see some effect on them.

After this, I found interesting the library model RF Cancerous tissue heating (or somewhat to this nature), but I am unable to use the same means found there to get results here (basically since there is a different cause, the antenna that causes the loss of power) - while typing, I also came to the realisation that perhaps my model - Magnetic, No Currents is unfit for this process, since from literature the said particles should be able to be heated from using an alternating field, so perhaps a re-done model is in order.

However, my question is - are there any tips that I can get, to succesfully finish my model? Is the simple model in Magnetic, No Currents (attached) correct? Does it actually do what it claims to do, or just seeing what I wish to see? How can I do the alternating field thing, to influence the (magnetic) particles inside the tissue? Also, from the Heat Sources menu, I only get User Defined input, whilst in the example from the library there are other options selectable (I assume because of the other physics, RF - and my Magnetic, No currents physics gives no other option than to manually give the W/m3 number)

Thank you for any possible help on this matter!
Lucian


1 Reply Last Post 18 mag 2012, 10:38 GMT-4
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 18 mag 2012, 10:38 GMT-4
Hi

MF physics can model magnetic fields, and the forces on domains you define that might interract with the magnetic field (by the fact that these domains have a mu-r different from the surrounding, hence influence the magnetic field and change the local field gradients), its the pendent of ES electrostatic that work on electric fields and charges.

Heating implies normally time changing fields and this you will not get from fixed magnets, except if you move them physicslly with a velocity. You might need, as you say, current flowing in a harmonic way hence you need to introduce some current flow domains or BCs, and frequency domain sweep or time series solving.

Heating from ar RF frequencies require the RF module as then your time variation is so short that the E fields variation is smaller than your object (with ACDC the hypothesis is that your field variation is much larger than the object)

--
Good luck
Ivar
Hi MF physics can model magnetic fields, and the forces on domains you define that might interract with the magnetic field (by the fact that these domains have a mu-r different from the surrounding, hence influence the magnetic field and change the local field gradients), its the pendent of ES electrostatic that work on electric fields and charges. Heating implies normally time changing fields and this you will not get from fixed magnets, except if you move them physicslly with a velocity. You might need, as you say, current flowing in a harmonic way hence you need to introduce some current flow domains or BCs, and frequency domain sweep or time series solving. Heating from ar RF frequencies require the RF module as then your time variation is so short that the E fields variation is smaller than your object (with ACDC the hypothesis is that your field variation is much larger than the object) -- Good luck Ivar

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