[FLASH-BUGS] Issue with shocks crossing refinement boundaries

[Colin McNally]

Hi,
            I have produced a setup which for me appears to cause some 
rather severe energy conservation issues in FLASH. What I have done is 
modify the standard Sedov test problem to simulate a run with a 
mass-based refinement criteria. The central region of the box is fixed 
to refinement level 5 and the exterior is fixed to refinement level 4. 
The problem appears to evolve correctly until thew shock hits the 
refinement boundary.  At this point the solution goes all wacky. A 
reflecting from the boundary of some sort ought to be expected, as FLASH 
doesn't seem to have anything in its prolong and refine operators to 
dampen this. A reflected wave is quite apparent in the solution. 
However, inspection of the outputted flash.dat file also shows 
significant energy loss.

  I have included a tarball with the flash.dat file from my run and the 
problem directory. I have reproduced this problem on a tru64/Compaq 
Fortran Alpha cluster with my own patched version of FLASH and a clean 
copy of FLASH2.1 on a Linux/Intel Fortran Intel box. The problem is run 
in 2D The differences from the original distributed Sedov test are as 
follows:
    - central 1/8th of box is fixed at refinement level 5
    - remainder of box at refinement level 4
    - larger box size (2 by 2 instead of 1 by 1)
    - longer run (to  t=0.4)
The setup command used was:
./setup sedovref -auto -2d

  I have observed that this issue does not appear when using truncation 
level refinement criteria. Also, the reflected wave is expected when 
using this forced refinement. However, non-conservation in a 
conservative hydro scheme is worrying. Similar situations where shocks 
must cross refinement boundaries will occur in astrophysical problems 
were refinement must be determined by a mass criteria(ex: cosmology 
problems).

Thanks,

Colin McNally
McMaster University

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