On Mon, Oct 19, 2009 at 12:46 AM, weasky <[email protected]> wrote:
>
> Hi,
>
> I noticed there are a couple of examples in the folder about
> cylindrical cords, and my question is about the the BCs:
> mesh.getFacesLeft(0) is the boundary for r=r_{inner}
> Right would be r_{outer}
> top would be z_{highest}
> bottom would be z_{lower}
>
> Is my understanding correct?

Yes, perhaps we should add in stub methods that are named something
more appropriate (inner, outer, upper,lower???).

> Basically, I want to solve a 2D diffusion
> eqn in a geometry of (r,z) and use the antisymmetry of the center
> line.

Antisymmetry? I'm not sure exactly what you mean. Is that just a typo?

> so for the BC part I will do
>  >>> boundaryConditions = (
>     ...  FixedFlux(faces=mesh.getFacesLeft(), value=0), #center-line, flux is > 0
> FixedValue(faces=mesh.getFacesRight(),value=valueRight),
> FixedValue(faces=mesh.getFacesTop(),value=z1),
>
> FixedValue(faces=mesh.getFacesBottom(),value=z0),
>      ...     )
>
> is my understanding correct?

I think that is all good, but I don't think you need a BC for the left
faces. Their surface area vanishes.

I have had issues with the corner cells for flow problems, I shift the
mesh away from 0 by some very small amount. You may or may not need to
this. I think it is only for flow problems that I found this to be
necessary.

Cheers

-- 
Daniel Wheeler

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