[FLASH-BUGS] Re: Problem with outflow/reflecting BCs

[Robi Banerjee]

Hi,

We encountered a problem in connection with outflow/reflecting
boundary conditions (still using FLASH 2.5). We stumbled over
this problem with setups which use the self-gravity module. Although,
the gravity module does not know about the hydro boundary conditions
the problem shows up most prominently when including self-gravity.

We prepared a few images on our web-page to illustrate what's going
wrong:

   http://www.ita.uni-heidelberg.de/~tpeters/flashbug.shtml

Essentially, the graviational potential is erroneous in the case of
outflow BCs and right if we use perodic BCs. This happens when the refinement 
structure changed (i.e. new blocks are added). This general
result is independent of the setup (in collapse calculations, the other 
quantities are subsequently screwed up).

Could it be that not all guard cells at the edge of the simulation box
are updated properly when using outflow/reflecting BCs?

Do you know about any problems in connection with the non-periodic BCs?

Thanks for your support.

All the Best,
Robi

  ======================================
  Robi Banerjee, Research Associate
  Institut fuer Theoretische Astrophysik
  Albert-Ueberle-Str. 2
  69120 Heidelberg
  Germany
  e-mail: banerjee at ita.uni-heidelberg.de
  tel.  : +49 6221 54-8967
  fax   : +49 6221 544221