[Getdp] Problem definition of static heat flow

[Christophe Geuzaine]

Kenny Erleben wrote:
> Hi All,
> 
> I have been reading the reference manual and looked through the examples,
> but I just don't get it. How do I write a formulation for the PDE of
> static heat flow? That is
> 
>   u_xx + u_yy = - q
> 
> Below I have attached my .msh

The mesh is fine. (Note that if you plan to analyze it with Gmsh later
on, you might want to specify non-zero elementary region numbers.)

> and .pro files.

As defined in your .pro file, the system has a zero right hand side: the
value of the Dirichlet constraint is 0, and the Neumann constraint is
wrong (you cannot impose the Neumann BC directly in the function
space--you need to explicitly define the appropriate surface term in the
formulation).

I attached a corrected version of heat.pro, with a Dirichlet BC on
the top, an explicit Neumann BC on the bottom, and implicit (null)
Neumann BC on the sides.

Cheers,

Christophe

-- 
Christophe Geuzaine

Tel: (626) 395-4552    http://www.geuz.org
Fax: (626) 578-0124    mailto:geuzaine at acm.caltech.edu







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