Table A2.

Greek Characters.

Character	Meaning
${\alpha }_{Ch,num}$	conveying angle obtained from numerical simulation
${\alpha }_{Ch}$	channel conveying angle
${\alpha }_G$	groove conveying angle
$\delta$	screw clearance; virtual overlap
$\mathsf{\Delta }F$	unknown additional force
${\overline{\mu }}_B$	average barrel friction coefficient
${\mu }_B$	barrel coefficient of friction
${\overline{\mu }}_i$	average internal coefficient of friction
${\mu }_i$	internal coefficient of friction
${\mu }_S$	screw coefficient of friction
${\nu }_{max}$	maximum Poisson’s ratio of DEM particles
${\rho }_{b,0}$	standard bulk density
${\rho }_{b,corr}$	corrected bulk density
${\rho }_{min}$	minimum density of DEM particles
$\phi$	helix angle in general
${\phi }_B$	helix angle at barrel
${\phi }_G$	groove angle
$\overline{\phi }$	mean helix angle
${\phi }_S$	helix angle at screw
${\overrightarrow{\omega }}_i$	angular velocity of DEM particle