[Getdp] Multiple natural boundary conditions

Wed Nov 5 13:02:35 CET 2014

Thanks a lot, you'are my savior, that's works now.
I've two other questions :
- How can i compute/save the nodal temperature field ? Now the
PostOperation block save the element field throught OnElementsOf.
- How can i compute the normal flux on a specified boundary :
\int_{\gamma_i}{\lambda \partial_n{T}ds}. To do so I need the normal vector
of each boundary edge. On which variable do I make sum : nodes or elements ?

Best regards.

Le mercredi 5 novembre 2014 08:50:54 UTC+1, michae... at infineon.com a écrit :
>
>  Hi,
>
>
>
> the small dimensions are fine. The problem is located in the definition of
> the
>
> physical groups: The lines have the same physical numbers as the surfaces,
>
> so GetDP cannot distinguish between them. Just use different numbers like
>
>
>
> Physical Line(11) = {1};
>
> Physical Line(12) = {16};
>
> Physical Line(13) = {2,19,15,17,12,8};
>
>
>
> Physical Surface(1) = {3};
>
> Physical Surface(2) = {2};
>
> Physical Surface(3) = {4};
>
> Physical Surface(4) = {1};
>
>
>
> in the case.geo file and
>
>
>
> Interieur = 11;
>
> Exterieur = 12;
>
>
> Zone1 = 1;
>
> Zone2 = 2;
>
> Zone3 = 3;
>
> Zone4 = 4;
>
>
>
> in the case.pro file.
>
>
>
> Cheers,
>
> Michael
>
>
>
>
>
> *From:* Hamid Badi [mailto:h.b... at bbs-slama.com <javascript:>]
> *Sent:* Wednesday, November 05, 2014 1:12 AM
> *To:* getdp-... at googlegroups.com <javascript:>
> *Cc:* h.b... at bbs-slama.com <javascript:>; ge... at geuz.org <javascript:>;
> Asam Michael (IFAG ATV BP D PD DES1)
> *Subject:* Re: [Getdp] Multiple natural boundary conditions
>
>
>
> Hi,
>
>
>
> Thanks a lot, it works too.
>
>
>
> I've an other similar problem, but getdp create a NAN temperature field, I
> can't explain it. The geometry is different but still with 3 BCs, the main
> different is that now i define all the dimension of my geometry im meter,
> so the coordinates are small.
>
>
>
> Le mardi 4 novembre 2014 17:12:43 UTC+1, michae... at infineon.com a écrit :
>
> Hi,
>
>
>
> the point is that in GetDP it’s not allowed to subtract or add anything
> from/to
>
> a Dof in a single Galerkin statement. Therefore you have to split your 2nd
>
> Galerkin into two:
>
> [image: Das Bild wurde vom Absender entfernt.]
>
>
>
> Then it works J
>
> [image: Das Bild wurde vom Absender entfernt.]
>
>
>
> Cheers,
>
> Michael
>
>
>
>
>
> *From:* getdp [mailto:getdp-... at ace20.montefiore.ulg.ac.be] *On Behalf Of
> *Sent:* Tuesday, November 04, 2014 1:14 PM
> *Subject:* [Getdp] Multiple natural boundary conditions
>
>
>
> Hello,
>
>
>
> My problem is common, i'd like to solve the heat equation with, for
> example, 2 natural Robin BC and one adibatique BC : -lambda.dnT = h.(T-Ti)
> on Gamma_i with i={1,2} and lambda.dnT = 0 on Gamma_3.
>
> I write the weak form with u in Form0 of the heat equation leads to the
> classical form :
>
>
>
> Equation{
>         In Omega; Jacobian JVol; Integration I1;}
>
>   Galerkin{ [ h[]* (Dof{u} - T[]), {u}];
>        In Ambiance; Jacobian JSur; Integration I1;}
> }
>
>
>
>
>
> In my problem there is no essential BC so i do not have Constraint block.
>
> The computation give a 0 temperature field, I do not understand what's
> wrong.
>
>
>
> Moreover :
>
> 1 - I wan to store in a file the temperature field respects to the nodes
> but PostOperation block computes over elements.
>
> 2 - How can I compute the integral of the flux over Gamma_i, to do so, I
> need for each boundary edge : the flux and the normal vector
>
>
>
> Best regards.
>
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