[FLASH-USERS] BCs for rotational symmetry in Flash3

[Aaron Froese]

Hi David,

I have been wanting a boundary condition like that for a long time, but have not had the time to tackle it myself.  Let me know if you get something that works.

Thanks,
Aaron

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Date: Tue, 10 Apr 2012 13:09:59 -0300
From: Dave <david.john.williamson at gmail.com>
Subject: [FLASH-USERS] BCs for rotational symmetry in Flash3
To: "flash-users at flash.uchicago.edu" <flash-users at flash.uchicago.edu>
Message-ID: <4F845B57.7090600 at gmail.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Hi,

I'm trying to figure out how to how to impose 4-fold rotational symmetry
boundary conditions in flash3 - e.g. the 3D simulation box is 1/8 of the
total volume, and the gas that flows out of the x=0 axis flows back into
the y=0 axis (with velocities rotated by 90 degrees).

Looking through the code, it appears the outflow, diode and reflective
boundary conditions are done on a block-by-block basis, while periodic
boundary conditions are done by just modifying the gid array.

However, I can't see an easy way to implement rotational symmetry with
either of these methods. Before I dive in and start doing things the
hard way, I was wondering if anyone has done this before and maybe has
some tips on how to apply these boundary conditions in a "natural" way
to Flash's architecture?

Cheers,
David
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