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simulation of rectangulaire straight conductor

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Hi everybody,

i want to simulate a straight conductor wire to find the magnetic field B and the inductance of the wire so i used the MEF in ACDC module so i defined the begining of the wire to terminal (0.1 A) and the end by the ground, but i get this message.

Failed to find a solution.
Divergence of the linear iterations.
Returned solution has not converged.

(the file is attached) thank you for ur help.


7 Replies Last Post 30.04.2013, 07:42 GMT-4
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 23.04.2013, 05:20 GMT-4
Hi
First of all you should use MF and not MEF for a simple B field from a current (MEF is far more complex and solves for the voltage)

Then also very important the B field is looping around in the "air or vacuum surrounding the wire, but you have not defined any volume with any mesh all around the wire.

Check the model library, you MUST use an air or vacuum region (block or large cylinder all around the wire so that the B field can develop in the numerical solution proposed

You example is far simpler to start with in 2D, just draw two circles, one for the wire and one much larger for the air, once you master the 2D you can try a 3D model

--
Good luck
Ivar
Hi First of all you should use MF and not MEF for a simple B field from a current (MEF is far more complex and solves for the voltage) Then also very important the B field is looping around in the "air or vacuum surrounding the wire, but you have not defined any volume with any mesh all around the wire. Check the model library, you MUST use an air or vacuum region (block or large cylinder all around the wire so that the B field can develop in the numerical solution proposed You example is far simpler to start with in 2D, just draw two circles, one for the wire and one much larger for the air, once you master the 2D you can try a 3D model -- Good luck Ivar

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Posted: 1 decade ago 23.04.2013, 05:28 GMT-4
thank you ivar it's clear ;))))
thank you ivar it's clear ;))))

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Posted: 1 decade ago 23.04.2013, 06:22 GMT-4
Hi ivar,

I think that's ok now what do you think....the model is attached

Cheers
Hi ivar, I think that's ok now what do you think....the model is attached Cheers


Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 23.04.2013, 07:05 GMT-4
Hi

That's much better ;)

but what you notice now is that with your sharp edges, you have singularities along the edges. For that its better to draw the section, fillet the corners, and extrude along the length

--
Good luck
Ivar
Hi That's much better ;) but what you notice now is that with your sharp edges, you have singularities along the edges. For that its better to draw the section, fillet the corners, and extrude along the length -- Good luck Ivar

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Posted: 1 decade ago 23.04.2013, 07:37 GMT-4
Ok thank you ivar ;)))
Ok thank you ivar ;)))

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Posted: 1 decade ago 30.04.2013, 06:30 GMT-4
Hi ivar,

now i simulate a 4 straight have the same length to find the magnetic field for the 3 component i found a result but i'm worry about the result because i'm not sure for the density of current..... actually i want a 1mA value of current but i'm not sure how i can define the density to get this value of current, i now I=j*dS but i define it at z component only or also for the 3 component,

(the file is attached) thank you for ur help.
Hi ivar, now i simulate a 4 straight have the same length to find the magnetic field for the 3 component i found a result but i'm worry about the result because i'm not sure for the density of current..... actually i want a 1mA value of current but i'm not sure how i can define the density to get this value of current, i now I=j*dS but i define it at z component only or also for the 3 component, (the file is attached) thank you for ur help.


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Posted: 1 decade ago 30.04.2013, 07:42 GMT-4
Hi ivar,

now i simulate a 4 straight have the same length to find the magnetic field for the 3 component i found a result but i'm worry because i'm not sure for the density of current..... actually i want a 1mA value of current but i'm not sure how i can define the density to get this value of current, i know I=j*dS but i define it at z component only.

(the file is attached) thank you for ur help.
Hi ivar, now i simulate a 4 straight have the same length to find the magnetic field for the 3 component i found a result but i'm worry because i'm not sure for the density of current..... actually i want a 1mA value of current but i'm not sure how i can define the density to get this value of current, i know I=j*dS but i define it at z component only. (the file is attached) thank you for ur help.

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