[FLASH-BUGS] cylindrical coordinates, avisco

[Tomasz Plewa]

On Fri, Sep 26, 2003 at 03:47:23PM -0400, Sean Matt wrote:
[snip]

> 	This actually raises the issue of whether the quantity (x(i)**2 -
> x(i-1)**2) is the right formulation for the calculation of the
> artificially viscocity.  We're not sure why the actual numerical value of
> the x coordinate should be relevant, since it is arbitrarily set by the
> user (e.g., 201**2-200**2 does not equal 2**2-1**2).  Perhaps what is
> needed is something like the square of the difference, (x(i) - x(i-1))**2,
> but since this is a different quantity, this should be looked at with
> care, and we don't know the correct formulation.

There should be no flow across the symmetry axis at r=0 (the area
vanishes there). The viscous flux (coefficient) should be set to zero.

Tomek
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