[Getdp] problems trying to couple Electrostatics and Magnetostatics
Thomas Jung
Thomas.Jung at iisb.fraunhofer.de
Fri Apr 7 14:32:29 CEST 2006
On Friday 07 April 2006 11:12, Thomas Jung wrote:
> Hi everybody,
>
> I am trying to calculate first the electrical potential in a rod, and from
> that the current and magnetic field. Its a very simple 3D-case - just a
> conducting rod, and a non-conducting cube around.
>
> There is a resolution "current": potentials at ends of rod are prescribed,
> field is computed, works fine.
>
> Then I have a resolution MagSta_a_3D, which, if I prescribe a fixed source
> current js in the rod, also works and gives me a reasonably looking
> magnetic field (well, except at the boundaries, or contact surfaces, where
> the magnetic field shows some strange arrows - maybe I have some boundary
> condition wrong here ?)
>
> However, when I try to couple both in resolution "both", the resulting
> fields and currents are completely wrong - there are current vectors only
> on the contact surface where I prescribe the electrical potential.
>
> Thank you very much for any hint !
found out that I had to change
Galerkin { [ -sigma[] * Dof{d v} , {a} ];
In DomainC_Mag; Jacobian Vol;Integration CurlCurl; }
to
Galerkin { [ -sigma[] * {d v} , {a} ];
In DomainC_Mag; Jacobian Vol; Integration CurlCurl; }
(i.e. {d v} instead of Dof{d v}, v beeing the electrical potential obtained
from the first resolution)
Now the current is fine, also the magnetic field looks good in the conductor,
however, there are strange arrows around in the air (see attached picture).
I also tried refining the mesh a lot, did not help.
Convergence is fine, btw. :
330 9.7053468e-12 1.3637123e-15
331 9.1444832e-12 1.2849045e-15
332 8.0479365e-12 1.1308272e-15
333 6.9006746e-12 9.6962374e-16
Solver : 333 Iterations / Residual: 7.944e-09
I have been searching a lot for similar cases in the mailing list, found e.g.
thus one:
[Getdp] Magnetostatic 3D problem
Pawel Kowol pawel.kowol at polsl.pl
Tue Apr 5 15:05:13 CEST 2005
applied the fixes suggested by Patrick Dular, and get a very similar result to
mine - also really strange b-vectors.
Sorry for bothering - but could please someone give me, as a starting point, a
working 3D b-conforming magnetostatics formulation, or have a look at my
formulation ?
Thank you !
--
Thomas Jung
Fraunhofer-Institut IISB
D-91058 Erlangen, Schottkystr. 10
+49 9131 761264
-------------- next part --------------
lc1 = 0.2;
lc2 = 0.02;
Point(1) = {0, 0, 0, lc1};
Point(2) = {1, 0, 0, lc1};
Point(3) = {0, 0, 1, lc1};
Point(4) = {1, 0, 1, lc1};
Point(5) = {0, 1, 0, lc1};
Point(6) = {1, 1, 0, lc1};
Point(7) = {0, 0.45, 0.45, lc2};
Point(8) = {0, 0.45, 0.55, lc2};
Point(9) = {0, 0.55, 0.55, lc2};
Point(10) = {0, 0.55, 0.45, lc2};
Point(11) = {0, 1, 1, lc1};
Point(12) = {1, 1, 1, lc1};
Point(13) = {1, 0.45, 0.45, lc2};
Point(14) = {1, 0.45, 0.55, lc2};
Point(15) = {1, 0.55, 0.55, lc2};
Point(16) = {1, 0.55, 0.45, lc2};
Line(1) = {2,1};
Line(2) = {1,3};
Line(3) = {3,2};
Line(4) = {3,4};
Line(5) = {4,2};
Line(6) = {5,1};
Line(7) = {2,5};
Line(8) = {2,6};
Line(9) = {6,5};
Line(10) = {5,10};
Line(11) = {10,1};
Line(12) = {5,11};
Line(13) = {11,10};
Line(14) = {1,7};
Line(15) = {7,3};
Line(16) = {10,7};
Line(17) = {9,11};
Line(18) = {11,3};
Line(19) = {3,9};
Line(20) = {9,10};
Line(21) = {8,3};
Line(22) = {7,8};
Line(23) = {8,9};
Line(24) = {11,4};
Line(25) = {11,12};
Line(26) = {12,4};
Line(27) = {2,16};
Line(28) = {16,6};
Line(29) = {12,6};
Line(30) = {16,12};
Line(31) = {4,13};
Line(32) = {13,2};
Line(33) = {13,16};
Line(34) = {12,15};
Line(35) = {15,4};
Line(36) = {16,15};
Line(37) = {4,14};
Line(38) = {14,13};
Line(39) = {15,14};
Line(40) = {6,11};
Line(41) = {13,7};
Line(42) = {8,13};
Line(43) = {8,14};
Line(44) = {13,10};
Line(45) = {16,10};
Line(46) = {14,9};
Line(47) = {15,9};
Line(48) = {9,16};
Line(49) = {9,7};
Line(50) = {13,15};
Line Loop(1) = {1,2,3};
Line Loop(2) = {4,5,-3};
Line Loop(3) = {6,-1,7};
Line Loop(4) = {8,9,-7};
Line Loop(5) = {10,11,-6};
Line Loop(6) = {-10,12,13};
Line Loop(7) = {14,15,-2};
Line Loop(8) = {-14,-11,16};
Line Loop(9) = {17,18,19};
Line Loop(10) = {-17,20,-13};
Line Loop(11) = {21,-15,22};
Line Loop(12) = {-21,23,-19};
Line Loop(13) = {-4,-18,24};
Line Loop(14) = {25,26,-24};
Line Loop(15) = {27,28,-8};
Line Loop(16) = {29,-28,30};
Line Loop(17) = {31,32,-5};
Line Loop(18) = {-27,-32,33};
Line Loop(19) = {-26,34,35};
Line Loop(20) = {36,-34,-30};
Line Loop(21) = {-31,37,38};
Line Loop(22) = {39,-37,-35};
Line Loop(23) = {-12,-9,40};
Line Loop(24) = {-29,-25,-40};
Line Loop(25) = {41,22,42};
Line Loop(26) = {43,38,-42};
Line Loop(27) = {16,-41,44};
Line Loop(28) = {33,45,-44};
Line Loop(29) = {-23,43,46};
Line Loop(30) = {-39,47,-46};
Line Loop(31) = {45,-20,48};
Line Loop(32) = {-47,-36,-48};
Line Loop(33) = {-16,-20,49};
Line Loop(34) = {-23,-22,-49};
Line Loop(35) = {-36,-33,50};
Line Loop(36) = {-38,-39,-50};
Plane Surface(1) = {1};
Plane Surface(2) = {2};
Plane Surface(3) = {3};
Plane Surface(4) = {4};
Plane Surface(5) = {5};
Plane Surface(6) = {6};
Plane Surface(7) = {7};
Plane Surface(8) = {8};
Plane Surface(9) = {9};
Plane Surface(10) = {10};
Plane Surface(11) = {11};
Plane Surface(12) = {12};
Plane Surface(13) = {13};
Plane Surface(14) = {14};
Plane Surface(15) = {15};
Plane Surface(16) = {16};
Plane Surface(17) = {17};
Plane Surface(18) = {18};
Plane Surface(19) = {19};
Plane Surface(20) = {20};
Plane Surface(21) = {21};
Plane Surface(22) = {22};
Plane Surface(23) = {23};
Plane Surface(24) = {24};
Plane Surface(25) = {25};
Plane Surface(26) = {26};
Plane Surface(27) = {27};
Plane Surface(28) = {28};
Plane Surface(29) = {29};
Plane Surface(30) = {30};
Plane Surface(31) = {31};
Plane Surface(32) = {32};
Plane Surface(33) = {33};
Plane Surface(34) = {34};
Plane Surface(35) = {35};
Plane Surface(36) = {36};
Surface Loop(1) = {1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,-25,-26,-27,-28,29,30,31,32};
Surface Loop(2) = {25,26,27,28,-29,-30,-31,-32,33,34,35,36};
Volume(101)={1};
Volume(102)={2};
Physical Surface (1) = {1,2};
Physical Surface (2) = {3,4};
Physical Surface (3) = {5,6,7,8,9,10,11,12};
Physical Surface (4) = {13,14};
Physical Surface (5) = {15,16,17,18,19,20,21,22};
Physical Surface (6) = {23,24};
Physical Surface (7) = {25,26};
Physical Surface (8) = {27,28};
Physical Surface (9) = {29,30};
Physical Surface (10) = {31,32};
Physical Surface (11) = {33,34};
Physical Surface (12) = {35,36};
Physical Volume (101) = {101};
Physical Volume (102) = {102};
-------------- next part --------------
A non-text attachment was scrubbed...
Name: test4_h.png
Type: image/png
Size: 137262 bytes
Desc: not available
URL: <http://www.geuz.org/pipermail/getdp/attachments/20060407/eb123b1f/attachment.png>
-------------- next part --------------
Integration {
{ Name CurlCurl ;
Case { {Type Gauss ;
Case { { GeoElement Triangle ; NumberOfPoints 4 ; }
{ GeoElement Quadrangle ; NumberOfPoints 4 ; }
{ GeoElement Tetrahedron ; NumberOfPoints 4 ; }
{ GeoElement Hexahedron ; NumberOfPoints 6 ; }
{ GeoElement Prism ; NumberOfPoints 9 ; } }
}
}
}
}
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Jacobian_Lib.pro
Type: text/x-objcsrc
Size: 182 bytes
Desc: not available
URL: <http://www.geuz.org/pipermail/getdp/attachments/20060407/eb123b1f/attachment.pro>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: InductionTestBox4.pro
Type: text/x-objcsrc
Size: 5138 bytes
Desc: not available
URL: <http://www.geuz.org/pipermail/getdp/attachments/20060407/eb123b1f/attachment-0001.pro>