# [Getdp] problems trying to couple Electrostatics and Magnetostatics

Thomas Jung Thomas.Jung at iisb.fraunhofer.de
Fri Apr 7 11:12:33 CEST 2006

```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 !

--
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 --------------
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: InductionTestBox4.pro
Type: text/x-objcsrc
Size: 5034 bytes
Desc: not available
Url : http://www.geuz.org/pipermail/getdp/attachments/20060407/1facd12e/attachment.pro
-------------- 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/20060407/1facd12e/attachment-0001.pro
```