[Getdp] Simple electrostatic simulation yields nan values everywhere

[Théo Mathurin]

Hello Christophe,

Many thanks for your reply.

That indeed solved the problem. Still, given this blunder I don't
understand why the computation worked with round conductors.

Best regards,

Théo Mathurin

Research engineer
Laboratoire Systèmes Electrotechniques et Environnement (LSEE) - Université
d'Artois

Le mar. 17 sept. 2019 à 21:44, Christophe Geuzaine <cgeuzaine at uliege.be> a
écrit :

>
> Hi Théo,
>
> You are integrating your volume stiffness matrix on DomainCC_Ele
>
>   Galerkin { [ eps[] * Dof{d v} , {d v} ] ; In DomainCC_Ele ; Jacobian Vol
> ; Integration GradGrad ; }
>
> but you define DomainCC_Ele to also include the (inner) boundary
> Skin_ins_conds
>
>     DomainCC_Ele += Region[{Skin_ins_conds}] ;
>
> Remove this and you should be fine.
>
> Christophe
>
>
> > On 17 Sep 2019, at 17:34, Théo Mathurin <theo.mathurin at univ-artois.fr>
> wrote:
> >
> > Hello everyone,
> >
> > I've encountered a strange issue with my electrostatic computation. I'm
> using the V formulation with the electric potential v saved as a
> post-operation output (see pro file attached).
> >
> > The geometry is desperately simple: two conductors in a square
> surrounding medium, each with its insulation. When the conductors are
> round, everything's fine and the electric potential is computed correctly.
> But when their shape is changed to rectangular, for some reason I get nan
> values everywhere in the domain.
> >
> > My msh file is generated using the Gmsh Python API. Attached is the
> corresponding Python script, where one can switch the shape from circles to
> rectangles. For debugging purposes, the script is written so that the
> minimal amount of code that is not shared by the two cases is isolated
> behind a conditional statement.
> >
> > Apparently, the problem arises when and only when one or several of the
> left or right insulation outer curves are straight lines. I have checked
> that there is nothing wrong with physical regions.
> >
> > In both cases I'm using the same pro file, and the command to run GetDP
> is the following:
> >
> > getdp -pro electrostatics.pro -msh test_geom.msh -solve EleSta_vf -pos
> get_v
> >
> > Note that I was able to carry out the very same computation successfully
> in a different, much more complicated geometry with rectangular conductors.
> I sincerely have no idea as to the root of this seemingly intractable
> problem, and therefore any help would be greatly appreciated. If needed, I
> can also provide the msh files I get when I'm running my Python script.
> >
> > Other potentially relevant information below
> > - Python API from Gmsh 4.4.1 Linux 64 bits SDK
> > - GetDP 3.2.0 Linux 64 bits
> > - Python 3.7
> > - Ubuntu 18.04.3
> >
> > Best regards,
> >
> > Théo Mathurin
> >
> > Research engineer
> > Laboratoire Systèmes Electrotechniques et Environnement (LSEE) -
> Université d'Artois
> >
> > <test_geom.py><electrostatics.pro
> >_______________________________________________
> > getdp mailing list
> > getdp at onelab.info
> > http://onelab.info/mailman/listinfo/getdp
>
> —
> Prof. Christophe Geuzaine
> University of Liege, Electrical Engineering and Computer Science
> http://www.montefiore.ulg.ac.be/~geuzaine
>
>
>
>
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