[FLASH-USERS] WARNING after gc filling and WARNING after amr_prolong

Sumit Banerjee sumitb at g.clemson.edu
Wed Jul 30 18:21:45 EDT 2025


Flash users,

I have been trying to simulate the Sod test problem using astronomical
units where the box dimensions are in parsecs and the corresponding
physical quantities are equal to the ambient surroundings in the ISM. I
have the density value to be 10^-23 on the left, 10^-24 on the right and
the pressure values to be 10^-12 on the left and 10^-13 on the right in the
cgs units. When I run the code, I am getting the below warning messages on
the log file and the plots (attached is from one of the check files) look
weird.

WARNING after gc filling: min. unk(DENS_VAR)=0.9999999999999999071852E-10
> PE=0 block=1 type=2
> WARNING after amr_prolong: min. unk(DENS_VAR)=0.9999999999999999071852E-10
> PE=0 block=1 type=2


GPT says this is because the density variable filled in the ghost cells are
below the threshold which is usually set to 10^-10.

I am not sure how I should proceed with this simulation. How do I set the
values of the density and pressure in the par file?

*Clear Skies,*
*Sumit (Sam)*
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://flash.rochester.edu/pipermail/flash-users/attachments/20250730/f28a5dbe/attachment-0001.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: sod_hdf5_chk_0002_Slice_z_density.png
Type: image/png
Size: 156030 bytes
Desc: not available
URL: <http://flash.rochester.edu/pipermail/flash-users/attachments/20250730/f28a5dbe/attachment-0003.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: sod_hdf5_chk_0001_Slice_z_density.png
Type: image/png
Size: 155687 bytes
Desc: not available
URL: <http://flash.rochester.edu/pipermail/flash-users/attachments/20250730/f28a5dbe/attachment-0004.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: sod_hdf5_chk_0000_Slice_z_density.png
Type: image/png
Size: 44824 bytes
Desc: not available
URL: <http://flash.rochester.edu/pipermail/flash-users/attachments/20250730/f28a5dbe/attachment-0005.png>


More information about the flash-users mailing list