Size segregation in a granular bore


Type
Article
Change log
Authors
Edwards, AN 
Vriend, NM 
Abstract

We investigate the effect of particle-size segregation in an upslope propagating granular bore. A bidisperse mixture of particles, initially normally graded, flows down an inclined chute and impacts with a closed end. This impact causes the formation of a shock in flow thickness, known as a granular bore, to travel upslope, leaving behind a thick deposit. This deposit imprints the local segregated state featuring both pure and mixed regions of particles as a function of downstream position. The particle-size distribution through the depth is characterized by a thin purely small-particle layer at the base, a significant linear transition region, and a thick constant mixed-particle layer below the surface, in contrast to previously observed S-shaped steady-state concentration profiles. The experimental observations agree with recent progress that upward and downward segregation of large and small particles respectively is asymmetric. We incorporate the three-layer, experimentally observed, size-distribution profile into a depth-averaged segregation model to modify it accordingly. Numerical solutions of this model are able to match our experimental results and therefore motivate the use of a more general particle-size distribution profile.

Description
Keywords
40 Engineering, 4019 Resources Engineering and Extractive Metallurgy
Journal Title
PHYSICAL REVIEW FLUIDS
Conference Name
Journal ISSN
2469-990X
2469-990X
Volume Title
1
Publisher
American Physical Society (APS)
Sponsorship
Natural Environment Research Council (NE/I021047/1)
This research was supported by the Returning Carers Scheme of the University of Cambridge. N.M.V. also acknowledges support from her NERC postdoctoral research fellowship NE/I021047/1 and her Royal Society Dorothy Hodgkin Research Fellowship RG130403.