J. Cao et al., GRAVITY GRANULAR FLOWS OF SLIGHTLY FRICTIONAL PARTICLES DOWN AN INCLINED BUMPY CHUTE, Journal of Fluid Mechanics, 316, 1996, pp. 197-221
Gravity-driven granular flow of slightly frictional particles down an
inclined, bumpy chute is studied. A modified kinetic model which inclu
des the frictional energy loss effects is used, and the boundary condi
tions for a bumpy wall with small friction are derived by ensuring the
balance of momentum and energy. At the free surface, the condition of
vanishing of the solid volume fraction is used. The mean velocity, th
e fluctuation kinetic energy and the solid volume fraction profiles ar
e evaluated. It is shown that steady granular gravity flow down a bump
y frictional chute could be achieved at arbitrary inclination angles.
The computational results also show that the slip velocity may vary co
nsiderably depending on the granular layer height, the surface boundar
y roughness, the friction coefficient and the inclination angles. The
model predictions are compared with the existing experimental and simu
lation data, and good agreement is observed. In particular, the model
can well predicate the features of the variation of solid volume fract
ion and fluctuation energy profiles for different particle-wall fricti
on coefficients and wall roughnesses.