[Getdp] Thermal coupling A-V formulation inside coils

[Gilles Vogt]

For the record, I found out my mistake : the coil was set as a conductor.
However, if the current is set, it should be in the non-conductors domain.

Best regards.

--
Gilles VOGT
Ingénieur généraliste de l'École Centrale de Lille, docteur en génie
électrique
+33 (0)6 25 98 72 02

2015-03-17 15:19 GMT+01:00 Gilles Vogt <vogtgilles at gmail.com>:

> Hi,
>
> I am using getdp to solve a 2D magneto-thermic problem based on the wiki
> example (
> http://onelab.info/wiki/Magnetodynamics_with_cohomology_conditions).
>
> At the moment, I am using the A-V formulation, which is in my opinion
> easier than the T-Ω formulation. However, I have some trouble about the
> heating power inside my coil domain.
>
> In post-pro, my evaluation of the ohmic losses is right in every domain :
> sigma[]*((Re[{ur}]-Im[w*{a}])*(Re[{ur}]-Im[w*{a}]) +
> (Im[{ur}]+Re[w*{a}])*(Im[{ur}]+Re[w*{a}]))
> where w=2*pi*f, {ur} the electric potential and {a} the magnetic vector
> potential
> (which is the same as sigma[]*SquNorm[Dt[{a}]+{ur}]).
>
>
> However, the following formulation does not produce good results when the
> coil is included in Omega_c2 :
>       Galerkin { [ -sigma[]*((Re[{ur}]-Im[w*{a}])*(Re[{ur}]-Im[w*{a}]) +
> (Im[{ur}]+Re[w*{a}])*(Im[{ur}]+Re[w*{a}]))  , {t} ];
>       In Omega_c2; Integration CurlCurl; Jacobian Vol;  }
> For some reason, the temperature increases far too much in the coil even
> if the ohmics losses are still OK when post-processed.
>
> I have been able to work around this behavior with :
> Galerkin { [ -qVol[]  , {t} ];
>       In ***COIL DOMAIN***; Integration CurlCurl; Jacobian Vol;  }
> Galerkin { [ -sigma[]*((Re[{ur}]-Im[w*{a}])*(Re[{ur}]-Im[w*{a}]) +
> (Im[{ur}]+Re[w*{a}])*(Im[{ur}]+Re[w*{a}]))  , {t} ];
>       In ***OTHER DOMAINS***; Integration CurlCurl; Jacobian Vol;  }
> where qVol=(I/section)^2/sigma...
>
> My results seem right, but I am a bit vexed because I cannot understand
> where is my mistake... Can anyone pinpoint my error ?
>
> PS : obviously
> Galerkin { [ -1/sigma[]* (Re[{js}]*Re[{js}]+Im[{js}]*Im[{js}]), {t} ];
> In ***COIL DOMAIN***; Integration CurlCurl; Jacobian Vol;  }
> doesn't work either...
>
> Best regards,
> --
> Gilles VOGT
>
>
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