Re: [ff3d-users] Setting boundary conditions!!

[Stephane Del Pino]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Le jeudi 27 Mai 2004 00:51, Arun Viswanathan a écrit :
> Hi Stephane!!
Hello Arun.

> 1. I will need to add one more boundary condition to
> my code. Among the 12 cylinders, incase 1 (or more) of
> them leak, I would like to pass this as a boundary
> condition as well. That is, the leak will simply act
> like a source for the entry of the substance into the
> container, and I would like to define the source among
> the boundary conditions. How can I do this??
I am not sure that I really understand what you want to do. If you just mean 
imposing different boundary conditions to different cylinders, you just have 
to give them different colors. Then you have to define your domain this way:
        domain O = domain(S, outside(<1,0,0>) and outside(<0,1,0>));
for instance. Then you just impose your boundary condition in a standard way, 
for instance:
        solve (u) in O by M
        {
          pde(u) -div(grad(u))=f;
                dnu(u) = 0 on <1,0,0>; // homogeneous Neuman
                u+dnu(u) = g on <0,1,0>; // some Robin condition
        }

Is that what you are looking for?

You  can also use the geometry to define functions:
        domain O2 = domain(S,inside(<0,0,1>));
        function KiO2 = one(<0,0,1>);
This later instruction defines a function whose value is 1 inside O2 and 0 
outside...

> 2. Also, how can I pass this information (regarding
> the source of leak) to the code, without hard-coding
> it. I plan to determine the rate at which the chemical
> escapes from the leak using another formula. How can I
> do that here, can I code it in C?? Or should it be
> some other language, like Java or Perl?? I tried using
> 'printf' and 'cout' before, they didn't work!! So how
> can I add other code??
What do you mean. Do you want to modify ff3d or do you want to create your own 
code? cout is working in ff3d, just tell me what you really want to do. If 
you are looking for adding features, you will have to learn C++. It could be 
quite difficult if you are not aware of it, but some people already did that.

Best regards,
Stephane.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.4 (GNU/Linux)

iD8DBQFAuKMdbZyhKhZwdc0RAsMkAKC3YQfeAgjgPehDYb09YBsz9WNWVgCgo0dS
jcEvyHvQuhdkNCERfVdlEZ8=
=MI8f
-----END PGP SIGNATURE-----