[FLASH-USERS] AMR grid with paramesh: jump to lower refinement level during simulation

[ERNESTO ZURBRIGGEN]

Dear Ondrej,
an option for modifying the maximum refinement level during runtime is
using the runtime parameters:
gr_lrefineMaxByTime; gr_lrefineMaxRedTRef; gr_lrefmaxTimeValue_*
and gr_lrefmaxTime_*.

Hope this helps.
Best,
Ernesto

On Wed, 15 Apr 2026 at 03:41, Ondřej Zajan <zajanond at fel.cvut.cz> wrote:

> Dear FLASH Users,
>
> During an ongoing simulation, I forced FLASH 4.8 to reduce the maximum
> grid refinement level (lrefine_max) by adjusting the refinement cutoffs.
> I saved this state to a checkpoint file and subsequently initialized a
> new simulation with the reduced maximum refinement level.
>
> The simulation runs temporarily but eventually terminates with the
> following error: "DRIVER_ABORT: Got nonzero ierr from
> HYPRE_SStructMatrixSetValues!".
>
> I suspect that the PARAMESH block tree requires rebuilding to properly
> eliminate the highest refinement level inherited from the initial
> simulation. I believe the failure occurs within the following file:
>
> FLASH4.8\source\Grid\GridSolvers\HYPRE\MHD\paramesh\gr_hypreCreateMatrix1BlkMag.F90.
>
> Could anyone advise on how to accomplish this tree rebuild, or suggest
> an alternative method for reducing the grid resolution during runtime?
>
> Thank you in advance for your time and assistance.
>
> Sincerely,
>
> Ondřej Zajan
> Ph.D. Student
> Faculty of Electrical Engineering, Czech Technical University in Prague
> _______________________________________________
> flash-users mailing list
> flash-users at flash.rochester.edu
>
> For list info, including unsubscribe:
> https://flash.rochester.edu/mailman/listinfo/flash-users
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://flash.rochester.edu/pipermail/flash-users/attachments/20260415/66dd00bf/attachment.htm>