Force calculation on an axisymmetric model

[Paulo José Gameiro Pereirinha <ppereiri@xxxxxxxxxxx>]

Hello! 

I'm in Portugal and trying to compute the atraction magnetic force on an
plunger electromagnet with axisymmetric geometrie. I'm using the Femm 3.0. 
To compute the force exerced on the iron can I just define a contour in the
air around the iron (which means that one side of the contour will be on
the line of coordinate z=0) and integrate the Maxwell Stress Tensor? (i.e.
is this command valid for axisymmetric models?). If I do so, I obtain
-2.783e-3 N, but the experimental result is about 1.35 N. I'm sending the
model in attachement.

Thanks in advance.

[Format] = 3.0
[Frequency] = 0.000000
[LengthUnits] = centimeters
[ProblemType] = axisymmetric
[Coordinates] = cartesian
[Comment] = "Problema PADE: Lab. electromagnetismo.\nElectroiman cilíndrico, calculo de forças, etc."
[PointProps] = 0
[BdryProps] = 1
<BeginBdry>
<BdryName> = "New Boundary"
<BdryType> = 0
<A_0> = 0.000000
<A_1> = 0.000000
<A_2> = 0.000000
<Phi> = 0.000000
<c0> = 0.000000
<c1> = 0.000000
<Mu_ssd> = 0.000000
<Sigma_ssd> = 0.000000
<EndBdry>
[BlockProps] = 3
<BeginBlock>
<BlockName> = "Air"
<Mu_x> = 1.000000
<Mu_y> = 1.000000
<H_c> = 0.000000
<H_cAngle> = 0.000000
<J_re> = 0.000000
<J_im> = 0.000000
<Sigma> = 0.000000
<d_lam> = 0.000000
<Phi_h> = 0.000000
<LamType> = 0
<LamFill> = 1.000000
<BHPoints> = 0
<EndBlock>
<BeginBlock>
<BlockName> = "Copper1"
<Mu_x> = 1.000000
<Mu_y> = 1.000000
<H_c> = 0.000000
<H_cAngle> = 0.000000
<J_re> = 1.539235
<J_im> = 0.000000
<Sigma> = 0.000000
<d_lam> = 0.000000
<Phi_h> = 0.000000
<LamType> = 0
<LamFill> = 1.000000
<BHPoints> = 0
<EndBlock>
<BeginBlock>
<BlockName> = "Steel with reluct 575 m/H"
<Mu_x> = 1384.000000
<Mu_y> = 1.000000
<H_c> = 0.000000
<H_cAngle> = 0.000000
<J_re> = 0.000000
<J_im> = 0.000000
<Sigma> = 0.000000
<d_lam> = 0.000000
<Phi_h> = 0.000000
<LamType> = 0
<LamFill> = 1.000000
<BHPoints> = 0
<EndBlock>
[CircuitProps] = 0
[NumPoints] = 20
0.000000	-1.000000	0	0
0.000000	10.500000	0	0
1.400000	0.000000	0	0
3.500000	0.000000	0	0
1.400000	-7.100000	0	0
3.500000	-7.100000	0	0
0.500000	-1.000000	0	0
0.500000	10.500000	0	0
0.000000	100.000000	0	0
0.000000	-100.000000	0	0
100.000000	100.000000	0	0
100.000000	-100.000000	0	0
15.000000	15.000000	0	0
0.000000	15.000000	0	0
0.000000	-15.000000	0	0
15.000000	-15.000000	0	0
0.000000	12.000000	0	0
1.000000	12.000000	0	0
0.000000	-3.000000	0	0
1.000000	-3.000000	0	0
[NumSegments] = 23
1	0	-1	1	0	0
6	0	-1	0	0	0
6	7	-1	0	0	0
1	7	-1	0	0	0
2	3	-1	0	0	0
3	5	-1	0	0	0
5	4	-1	0	0	0
4	2	-1	0	0	0
8	10	-1	1	0	0
10	11	-1	1	0	0
11	9	-1	1	0	0
9	14	-1	1	0	0
14	18	-1	1	0	0
8	13	-1	1	0	0
12	13	-1	0	0	0
12	15	-1	0	0	0
15	14	-1	0	0	0
1	16	-1	1	0	0
16	13	-1	1	0	0
18	0	-1	1	0	0
16	17	-1	0	0	0
17	19	-1	0	0	0
19	18	-1	0	0	0
[NumArcSegments] = 0
[NumHoles] = 0
[NumBlockLabels] = 5
0.300000	3.900000	3	2.000000e-001	0	0.000000	0
2.400000	-3.700000	2	5.000000e-001	0	0.000000	0
38.000000	27.000000	1	5.000000e+000	0	0.000000	0
11.000000	-4.000000	1	5.000000e-001	0	0.000000	0
0.300000	-2.200000	1	3.500000e-001	0	0.000000	0

Paulo Pereirinha

------------------------------------------------

Paulo José Gameiro Pereirinha 
Departamento de Engenharia Electrotécnica
Instituto Superior de Engenharia de Coimbra
Quinta da Nora -Apartado 10057
3030-601 Coimbra, Portugal

Tel.	Gabinete:	+351-239 790242
Telefonista:	+351-239 790200
Fax:	+351-239 790270