[FLASH-BUGS] Bug in quadratic_cartesian interpolation scheme?

[Mike Zingale]

Hi Robi, the only problem that I am aware of with those prolongation
routines is that the monotonicity constraint does not operate on the mass
fractions as a whole, so it does not guarantee that they sum to one at the
end -- this is something that I've been meaning to fix, but have not had
the time.  

I have not seen a problem like you describe.  More information would be
useful -- especially if you could reproduce the problem in 2-d, as it
would be easier to debug then.

Mike

------------------------------------------------------------------------------
Michael Zingale
UCO/Lick Observatory
UCSC
Santa Cruz, CA 95064

phone:  (831) 459-5246 
fax:    (831) 459-5265
e-mail: zingale at ucolick.org
web:    http://www.ucolick.org/~zingale

"Once something has been approved by the Government, It's no longer immoral."
   -- Reverend Lovejoy







On Wed, 5 Nov 2003, Robi Banerjee wrote:

> Hi,
> 
>   I ran into a problem (non convergence in the Riemann solver)
> using the new 'quadratic_cartesian' interpolation scheme in a
> 3D simulation including selfgravity. 
>   Looking into the details after a refinement step I figured 
> that the data in the newly refined blocks develop stripe-like
> structures. This leads, for instance, to overshooting in 
> velocities, resp. mach numbers. 
>   Using the old interpolation scheme (second_order_old) 
> everything is fine and the variables are smoothly prolongated 
> onto the newly refined blocks.
> 
>   Is this a known problem, or is there a problem with the
> new (quadratic_cartesian) interpolation scheme?
> 
>   If you need more information, please don't hesitate to
> ask for (e.g. 2D slices of the simulation data with the
> two different interpolations schemes)
> 
>   Thank you,
> Robi
> 
> ====================================
> Robi Banerjee
> Department of Physics and Astronomy
> ABB-320, McMaster University
> Hamilton, ON L8S 4M1
> CANADA
> e-mail: banerjee at physics.mcmaster.ca
> phone : (905) 525-9140 x 23189
> fax   : (905) 546-1252
>  
>