[Getdp] Possible Bug: 2*pi missing when integrating over Volumes in Axisymmetrical Models

Dr.-Ing. Malte Hinrichs hinrichs at miniatursysteme.de
Sat Mar 7 11:03:10 CET 2009


Hello!

First of all, I want to thank your for your great dedication to the 
development of a powerful OS-FEM-Suite!

When evaluation the total field-energy in an axi-symmetrical model  I 
stumbled across the phenomenon that the result is too low by the 2*pi. I 
verified this behaviour by integrating the constant 1 over a cylindrical 
Volume with the dimensions D=10 mm and L=10 mm.
The result yields 0.5e-7 (= Rm * D * L, Rm=D/2), while it should be 
2*pi*Rm*D*L=pi*1.e-7.

I included an example project, which is mainly an adaptation of your 
magnetostatic example files.
Name of cylindrical Volume: Arm - Armature
Relevent lines:
debug.geo: 5-9, 31-42
debug.pro: 23, 116
Mag-2D-AZ-Debug.pro: 174

Please let me know, if this is not a Bug, but an error on my side!

Sincerely,

Malte Hinrichs


"getdp --version"
1.2.1

"getdp debug -pre MagSta_a   -cal -pos a" :
...
P o s t - P r o c e s s i n g . . .
Info      : Selected PostProcessing 'MagSta_a'
Info      : Selected Mesh 'debug.msh'
Operation : PostOperation 1/5
          > 'a.pos'
Operation : PostOperation 2/5
          > 'b_a.pos'
Operation : PostOperation 3/5
          > 'Wint.pos'
Operation : PostOperation 4/5
          > 'w.pos'
Operation : PostOperation 5/5
0  4.999999999979999e-07                             <--- This is it
Resources : cpu 0.576036 s
E n d   P o s t - P r o c e s s i n g
E n d



-- 
==========================================
Dr.-Ing. Malte Hinrichs
Gleimstraße 24
D-10437 Berlin
Tel   +49 (0)30 48 49 67 62
Mobil +40 (0)151 17 82 21 69

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