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Moving ferromagnetic objects inside magnetic field
Posted Sep 7, 2012, 3:33 a.m. EDT Low-Frequency Electromagnetics, Modeling Tools & Definitions, Parameters, Variables, & Functions 3 Replies
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Dear COMSOL experts,
for our research we would need to simulate moving metallic leaves of finite extent inside a magnetic field generated by multiple coils carrying a DC current (i.e. no changing fields). We are interested in the influence of the movement on the magnetic field as well as in the forces on the metallic leaves, which includes eddy-currents induced in the leaves and probably in the coils. The velocity of the leaves would be rather slow, so a quasi-static calculation would hopefully be accurate enough.
While it is certainly possible to model this scenario in the static case (where the leaves are not moving) using the COMSOL AC/DC Modul, I am not sure if simulating the moving metallic leaves would be possible.
Through reading online COMSOL documentation, I got the impression that including the velocity into the Lorentz / Maxwell equations is only possible in COMSOL under fairly restrictive conditions, for example it appears to be possible if the object moving is infinite in length alongside the direction of movement (infinite rail) or if you are looking at axis-symmetric object rotating around its axis of symmetry.
However, I have found no possibility so far of modelling a scenario where you have a moving conductive projectile inside a magnetic field.
So my questions are:
a) Can above described scenario be modelled in COMSOL with sufficient accuracy?
b) If yes, is it possible to feed COMSOL with a trajectory for the single metallic leaves and simulate the magnetic fields and forces over time?
Any help is gladly appreciated,
Tristan
for our research we would need to simulate moving metallic leaves of finite extent inside a magnetic field generated by multiple coils carrying a DC current (i.e. no changing fields). We are interested in the influence of the movement on the magnetic field as well as in the forces on the metallic leaves, which includes eddy-currents induced in the leaves and probably in the coils. The velocity of the leaves would be rather slow, so a quasi-static calculation would hopefully be accurate enough.
While it is certainly possible to model this scenario in the static case (where the leaves are not moving) using the COMSOL AC/DC Modul, I am not sure if simulating the moving metallic leaves would be possible.
Through reading online COMSOL documentation, I got the impression that including the velocity into the Lorentz / Maxwell equations is only possible in COMSOL under fairly restrictive conditions, for example it appears to be possible if the object moving is infinite in length alongside the direction of movement (infinite rail) or if you are looking at axis-symmetric object rotating around its axis of symmetry.
However, I have found no possibility so far of modelling a scenario where you have a moving conductive projectile inside a magnetic field.
So my questions are:
a) Can above described scenario be modelled in COMSOL with sufficient accuracy?
b) If yes, is it possible to feed COMSOL with a trajectory for the single metallic leaves and simulate the magnetic fields and forces over time?
Any help is gladly appreciated,
Tristan
3 Replies Last Post Sep 10, 2012, 5:17 p.m. EDT
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Posted:
1 decade ago
Hi
I believe so, but you should use MEF whcih is rather "heavy", you have the example of the magnet falling in a copper cylinder and being damped by induced eddy currents, its a 2D-axi but linear not rotating
Certainly in 3D you should be abe to, remains how you define the trajectory, and in anycase forces extraction requires carefull meshing and "rounded off" geoemtries to minimise singularity points (sharp corners) that tend to drastically reduce the precision of the force estimation s
--
Good luck
Ivar
I believe so, but you should use MEF whcih is rather "heavy", you have the example of the magnet falling in a copper cylinder and being damped by induced eddy currents, its a 2D-axi but linear not rotating
Certainly in 3D you should be abe to, remains how you define the trajectory, and in anycase forces extraction requires carefull meshing and "rounded off" geoemtries to minimise singularity points (sharp corners) that tend to drastically reduce the precision of the force estimation s
--
Good luck
Ivar
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Posted:
1 decade ago
Hi Ivar,
thank you for your answer. Using MEF is definitely a good idea, but I could not find the example of the "falling magnet in the copper cylinder" you were talking about.in the model gallery. Could you provide a link for me?
Regards,
Tristan
thank you for your answer. Using MEF is definitely a good idea, but I could not find the example of the "falling magnet in the copper cylinder" you were talking about.in the model gallery. Could you provide a link for me?
Regards,
Tristan
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Posted:
1 decade ago
Hi
well then check with your local COMSOL rep, I have seen it from COMSOL side in one of their demos.
And I made one self back in 3.5 days I believe, but I cannot get hand on that one now, must be archived somewhere ...
Have you tried a search on the Forum ?
--
Good luck
Ivar
well then check with your local COMSOL rep, I have seen it from COMSOL side in one of their demos.
And I made one self back in 3.5 days I believe, but I cannot get hand on that one now, must be archived somewhere ...
Have you tried a search on the Forum ?
--
Good luck
Ivar