Re: boundary condition for NDSolve
- To: mathgroup at smc.vnet.net
- Subject: [mg45093] Re: boundary condition for NDSolve
- From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
- Date: Tue, 16 Dec 2003 06:21:44 -0500 (EST)
- Organization: Universitaet Leipzig
- References: <brfvbb$ffq$1@smc.vnet.net>
- Reply-to: kuska at informatik.uni-leipzig.de
- Sender: owner-wri-mathgroup at wolfram.com
Hi,
your irregular domain is a typical application for a finite
element program you should use this method because NDSolve[]
will not do that for you.
Regards
Jens
Yama Masu wrote:
>
> I would like to solve membrane oscillation between two square shaped fixed boundaries
> with NDSolve.
> D[u[x, y, t], {t, 2}] == D[u[x, y, t], {x, 2}] + D[u[x, y, t], {y, 2}] + f[x, y, t],
> where f is an external force.
>
> The boundary condition for the outside square is given by
> u[x, -1, t] == 0, u[x, 1, t] == 0, u[-1, y, t] == 0, u[1, y, t] == 0.
>
> How can I give the boundary condition for the square inside?
>
> I tried
> If[y>-0.5 && y<0.5, u[0.5, y, t]==0] etc. but this didn't work.
>
> Masu