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

[Ondřej Zajan]

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