Re: [ff3d-users] Inner wall definitions

[Emilio Melero García]

Hello Stephane,

Thank you for your mail!!. It was not exactly what i intended but nevermind, i already got it figured it out. What i needed was to define a geometry of a box containing a cylindrical pipe closed on one side, and i did that using a difference of two coaxial cylinders of suitable radius and lengths. However your mail help me to understand a bit more the role of the bacground mesh.

Now i need someone to help me. I have been stucked in a problem that, at the end, it was caused by the old version of ff3d i am using 1pre7 for mac os x. I have tried to download the cvs source code from savannah following the instructions in the ff3d web page and in the savannah page and no success!!

I have tried

 cvs -z3 -d:pserver:address@hidden:/sources/ff3d co ff3d

and no succes (connection time out)

and also tried
cvs -z3 -d:pserver:address@hidden:/sources/ff3d co ff3d

as per instructions in the savannah page. Can anybody help me??, please send me a copy of the source code so that i can compile it!!

Thank you very much

2007/1/26, Stephane Del Pino <address@hidden>:

Hello.

If I understand your question, you want to define different boundary
conditions on a cylinder using the fictitious domain approach of ff3d?

To do so, define a long cylinder using the POVRay description:
it should have the radius of the cylinder that defines your geometry. Then
define the embedding structured 3d mesh so that its intersection with the
cylinder define your domain.

You can then use 2 different boundary conditions for the base and the top of
the cylinder defining them using the background mesh and another one on the
cylinder side.

for instance if the mesh is 'm', your cylinder axis is along the 'y' direction
and its reference is <1,0,0>, and 'd' is the computational domain, you can do

        solve (u) in m by d
        {
          pde(u)
            -div(grad(u)) = f;
            u = 0 on M ymin;
            u = 0 on <1,0,0>;
            dnu(u) = 0 on M ymax;
        }

If you want ,you can also define completely your cylinder in POVRay using the
intersection of a plane and a (POV) cylinder : then you have 2 different
references ... I prefer the first approach.

Does this answers your question?

Best regards,
Stephane.



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-- 
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Dr. Emilio Melero García
Laboratorio de Estudios Cristalográficos, IACT
Instituto de parasitología Lopez Neyra,
P.T. Ciencias de la Salud, E-18100 Armilla, 
Granada, España

Correo elec. :emilio_arroba_lec_._csic_._es
Tfno: 958181621, lab 107
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