[Getdp] Multiple natural boundary conditions

Hamid Badi h.badi at bbs-slama.com
Tue Nov 4 13:14:07 CET 2014


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 :

      Galerkin{ [lambda[] * Dof{Grad u}, {Grad u}];
        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 

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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