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Relationship between B and H fields in cylindrical magnetization

  1. Jul 29, 2013 #1
    So I've been simulating a really simple geometry using ANSYS Maxwell. It is a cylinder only and I am looking at the [itex]\overrightarrow{B}[/itex] and [itex]\overrightarrow{H}[/itex] fields in order to see their relationship between them when the material is magnetized in the circumferential direction. I used a cylindrical coordinate system to describe the magnetization. So the direction of magnetization is in the [itex]\phi[/itex] direction.

    [itex]\overrightarrow{B}[/itex] using a BH-curve to define the magnetic material:
    [Broken]



    [itex]\overrightarrow{H}[/itex] using a BH-curve to define the magnetic material:
    [Broken]



    [itex]\overrightarrow{B}[/itex] using a scalar to define the magnetic material:
    [Broken]



    [itex]\overrightarrow{H}[/itex] using a scalar to define the magnetic material:
    [Broken]

    Notice that both BH-curve defined and scalar defined magnetic materials exhibit a kind of random/noise [itex]\overrightarrow{H}[/itex]. What is causing this phenomenon? Isn't [itex]\overrightarrow{H}[/itex] supposed to be in same direction as [itex]\overrightarrow{B}[/itex] external to the material and in the opposite direction interior?
     
    Last edited by a moderator: May 6, 2017
  2. jcsd
  3. Jul 29, 2013 #2

    marcusl

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    Possibly its an artifact of the finite-sized and coarse meshing, and of finite-precision arithmetic effects (number of digits, roundoff error, etc). The results are wrong in other ways as well; for instance, there should be no fields outside the cylinder.
     
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