For pure granular flow simulation in a channel, I am using hertz collisional model. I have provided all the input properties for the particle including coulomb friction coeff. and rolling friction coeff. but I am not sure about using no-slip, free-slip, partial slip and mixed wall boundary conditions.
For instance, is it valid to use no-slip BC at the wall surface for solid phase when I want the particles to slide and roll?
I wanted to know how the particle friction coefficients work with each wall boundary conditions (no slip, free slip, partial slip and mixed).
Please let me know about these BC for the pure granular flow case.
In a DEM simulation, the wall BC for the solids phase is defined by the particle/wall coefficients in the SOLIDS>DEM pane. There is no free-slip, partial slip (these are TFM settings).
I am still in doubt in selecting the appropriate Boundary type for the walls. Currently I am letting Mfix know that there is no-slip wall.
No slip BC means there is no kinetic friction involving right? Then how no slip boundary type works although we set all friction coefficient values for particles/walls.
You can ignore these settings and tooltips, these are for TFM. For a pure granular DEM simulation, they do not apply. NSW just means zero velocity at the wall, but again this applies to the gas phase or the solids phase in TFM. So when you say BC_TYPE=NSW with DEM, we are saying particles interact with a solid wall. The particles can bounce off the wall, and there can be friction between particles and walls.
