[FLASH-BUGS] Bug in Unsplit Hydro_computeDt

[Jason Galyardt]

Dear FLASH developers,

In looking at source/physics/Hydro/HydroMain/unsplit/Hydro_computeDt.F90 to
correct a bug reported to the flash-users list by Mark Richardson, I
noticed another bug. Line 239 in the FLASH 4.3 version of this file reads
as follows:

if (NDIM > 2) dt_ltemp =
max(dt_ltemp,(abs(U(VELZ_VAR,i,j,k)-uzgrid(j))+sqrt(cfz2))*delzinv)

However, I believe the index of the uzgrid array is incorrect; the index
'j' should be 'k', yielding:

if (NDIM > 2) dt_ltemp =
max(dt_ltemp,(abs(U(VELZ_VAR,i,j,k)-uzgrid(k))+sqrt(cfz2))*delzinv)

I've not noticed any problems traceable to this bug, though I can verify
that the corrected version is functional. Given that Mark Richardson's bug
was first identified in unsplit_rad/Hydro_computeDt.F90, the bug identified
above likely affects the unsplit_rad version of this routine as well.

Best Regards,

Jason

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Jason Galyardt
Department of Physics and Astronomy
University of Georgia