Difference between normal ghost, entering ghost and existing ghost

MFiX
#1

Hi,
as far as I know, the particles has many particle states. In the discretement_mod.f, the normal ghost，entering ghots and existing ghots is not explained well.
so I am wondering what is the difference between them in collision detection and gas-solid intereacation ? Is it realated to mpi run?

Kind regards
Yuanhe

#2

These are internal flags and do not require user settings. “Entering” state is used at mass inlets, “Exiting” is used at outlet BCs. These are set when a particle start crossing an inlet or BC plane. “Ghost” refers to the shared layers among processors when running in parallel mpi.