[Getdp] Difficult BC

[Nacho Andres de la Fuente]

Hi Christophe,

As a reminder of my problem:

> Hi there!
> 
> First of all congratulations for the work you are doing.
> 
> Let me please explain you my little problem: I have to solve Laplace
and
> Helmholtz equation for a determined geometry and having learnt gmsh I
> would like to use an open source FE solver. Could you recommend me
one?
> (apart from Getdp .. I do not know if this is a good question since
this
> is the Getdp e-mail list ..:-)). How is Getdp behaviour in what
concerns
> non cartesian coordinates?
> 
> Since i am trying Getdp as well and the question to the previous
> question is obviously Getdp, I would like to know if it is possible
that
> someone could send me an example (or the exact example in the case
that
> someone has solved an electromagnetic prblem with the aforementioned
> equations) to see the writing + combination with gmsh. It does not
need
> to be too extended but also not too short. I already have the
manual(s),
> but seeing the whole problem makes it always easier and more direct.
> 

> Check out the demos/ directory of the getdp distribution--it contains
> an example for Poisson's equation.

Ok, now you probably remember my Photoelectric emission problem ...

My geometry consists of two concentric cylinders inside of a sphere
(i.e. geometrically is axialsymmetric) .. the BC however, are NOT
axialsymmetric and depend on the colatitude angle:
	* which type of Jacobian should I use? If I understood correctly, I
have a geometry in gmsh, I apply the normal Laplacian(phi) = 0 and by
using Jacobian, any Riemann geometry can be solved, am I right? could
you comment a little on this please?
	* for those Neumann BC on he surface of the outer sphere I need to
define a function that depends on the point of the boundary in which we
are and the value of phi (the exponential of the value of the potential
at that point and the coltitude at that point), how can I do that? I
mean to recover the value of the position of the node that it is being
used in that moment? because it is better to use nodes here isn't it? (I
mean for the FunctionSpace ..). How can I include the value of what I am
going to solve into the function?

Many thanks and sorry for bothering you with probably stupid questions
..

Nacho