[FLASH-BUGS] Bug in Unsplit Hydro_computeDt

[Jason Galyardt]

Dear FLASH developers,

My apologies -- I reported the same bug that Mark found. There are two new
bugs in source/physics/Hydro/HydroMain/unsplit/Hydro_computeDt.F90 on lines
188 and 190, also having to do with array indices:

!~~~~
jmS = max(blkLimits(LOW,IAXIS), jmS)
!...
jpS = min(blkLimits(HIGH,IAXIS), jpS)
!~~~~

The 'IAXIS' on both lines should be 'JAXIS', I believe. Here are the
corrected lines:

!~~~~
jmS = max(blkLimits(LOW,JAXIS), jmS)
!...
jpS = min(blkLimits(HIGH,JAXIS), jpS)
!~~~~

Sorry about the confusion. Again, these bugs are also in
source/physics/Hydro/HydroMain/unsplit_rad/Hydro_computeDt.F90.

Best Regards,

Jason


On Fri, Feb 12, 2016 at 3:52 PM, Jason Galyardt <jason.galyardt at gmail.com>
wrote:

> 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
>
> ----
> Jason Galyardt
> Department of Physics and Astronomy
> University of Georgia
>
>