Units used in granular pair styles and in in.granregion.funnel example file

I have not seen any recent discussion of units in the granular pair styles, and was unable to find an answer to this question, so my apologies if it has been addressed previously. For most of my granular simulations, I have been using the dimensionless units LJ. However, I have a question about an example file, in.granregion.funnel, that is available on the lammps website (incidentally, who is the author of that file?). The files lists “units si”, and writes all the usual parameters (kn, kt, gamma_n, gamma_t) in terms of the elastic constants (young’s and shear moduli) in these units. But particle radii are 0.5, and the acceleration of gravity is 1. Does this mean that particles have diameter 1m, since we are in SI units? Or is it using non-dimensional units for these in a fashion I have not been able to identify?

Thanks in advance for your help.


Not sure, but @jtclemm was the last that modified it (according to git).

I did not create the original script, but I believe what you stated is technically correct: the radius is half a meter and gravity is 1.0 m/s^2. However, since this is just an example I think the units were arbitrary with the intention that results would be nondimensional.

Thank you both very much for the quick response!