[FLASH-USERS] Unit conversion in RHD riemann problem

[Sifei Zhang]

Dear FLASH experts,

I have a question regarding the unit convention in RHD Riemann problem. In the manual, it says that the conservation laws are written in the units of c=1, and the same convention is adopted in FLASH code in section 14.2.2

However, in the .log output file I found a line pc_unitsbase                = CGS  which indicates otherwise.

In this case what are the actual unit of grid dimension, timestep, density, pressure and velocity in the output hdf5 files? Are they converted into CSI units or still in c=1 convention? I noticed that velocity in the hdf5 files are using unit (c=1).  If they are in c=1 convention, what units does the properties have ( for example GeV, MeV or eV)? I need these information to calculate the CFL condition and PDE residual.

Please find the attached my .par file. I am using FLASH4.7.1, the example RHD Riemann simulation.

Thank you,
Sifei

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://flash.rochester.edu/pipermail/flash-users/attachments/20251126/9647d02a/attachment.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: flash.par
Type: application/octet-stream
Size: 2320 bytes
Desc: flash.par
URL: <http://flash.rochester.edu/pipermail/flash-users/attachments/20251126/9647d02a/attachment.obj>