A unified description of gravity- and kinematics-induced segregation forces in dense granular flows

Particle segregation is common in natural and industrial processes involving flowing granular materials. Complex, seemingly contradictory, phenomena have been observed for different boundary conditions forcing. Using discrete element method simulations, we show that of a single particle intruder can be described unified manner across flow configurations. A scaling relation the net force obtained by measuring forces on an controlled-velocity flows where gravity kinematics are varied independently. The law consists two additive terms: buoyancy-like gravity-induced pressure gradient term shear rate term, both which depend size ratio. reflects kinematics-driven mechanism whereby larger (smaller) intruders pushed toward higher (lower) regions. validated, without refitting, wall-driven flows, inclined vertical silo free surface down inclines. Comparing to weight results predictions direction match experimental computational various