Factor M and L in check_solids_dem_mod

[Fei]

Hi everyone,

For the CHECK_SOLIDS_DEM_COLL_LSD subroutine in the check_solids_dem_mod code file, there are two factors, M and L. These two factors seem to denote solid phase indexes.

Some parameters like the effective mass of colliding particles and the collision time scale are definated relating to M and L.

However, collisions depend on each colliding particles. For example, it may be easier to be understood, if mass_eff = mass(particle_1)*mass(particle_2)/(mass(particle_1)+mass(particle_2)). And, each solid phase may have their diameter distributions.

M and L in the code file mean phase indexe or particle index? How to understand the code if M and L refer to phase indexe.

Thank you.

[jeff.dietiker]

Here M and L represent the phase indices. We cannot use a different time step for each pair of particles. The global time step is based on the smallest collision time among all all particles. We use the smallest particle size in each phase to get a reference mass for each phase and then compute the collision time for all pairs of phases.

[Fei]

Thank you very much. I have also found the codes for calculating the min particle size for each solids phase in the check_solids_dem_mod file.