TY - JOUR
T1 - Shape matters
T2 - Competing mechanisms of particle shape segregation
AU - Hernández-Delfin, D.
AU - Tunuguntla, D. R.
AU - Weinhart, T.
AU - Hidalgo, R. C.
AU - Thornton, A. R.
N1 - Funding Information:
D.H. acknowledges support from Asociación de Amigos de la Universidad de Navarra, MercuryLab, and Fundación Caja Navarra-Caixa. This work was partially funded by Ministerio de Economía y Competitividad (Spanish Government) through Project No. PID2020-114839GB-I00 MINECO/AEI/FEDER, UE. R.C.H. acknowledgments support from the European Union's Horizon 2020 Research and Innovation Programme under the Marie Sklodowska-Curie Grant Agreement CALIPER No. 812638. A.T. acknowledges the support of the Dutch Research Council, STW-Vidi Project No. 13472. T.W. acknowledges the support of the Dutch Research Council, NWO-TTW Grants No. 15050 and 16604. Finally, we acknowledge the contributions of I. F. C. Dennissen, who started the superquadrics implementation and the early simulations on this topic.
Publisher Copyright:
© 2022 American Physical Society.
PY - 2022/11/15
Y1 - 2022/11/15
N2 - It is well known that granular mixtures that differ in size or shape segregate when sheared. In the past, two mechanisms have been proposed to describe this effect, and it is unclear if both exist. To settle this question, we consider a bidisperse mixture of spheroids of equal volume in a rotating drum, where the two mechanisms are predicted to act in opposite directions. We present evidence that there are two distinct segregation mechanisms driven by relative overstress. Additionally, we showed that, for nonspherical particles, these two mechanisms (kinetic and gravity) can act in different directions leading to a competition between the effects of the two. As a result, the segregation intensity varies nonmonotonically as a function of aspect ratio (AR), and, at specific points, the segregation direction changes for both prolate and oblate spheroids, explaining the surprising segregation reversal previously reported. Consistent with previous results, we found that the kinetic mechanism is dominant for (almost) spherical particles. Furthermore, for moderate aspect ratios, the kinetic mechanism is responsible for the spherical particles' segregation to the periphery of the drum, and the gravity mechanism plays only a minor role. Whereas, at the extreme values of AR, the gravity mechanism notably increases and overtakes its kinetic counterpart.
AB - It is well known that granular mixtures that differ in size or shape segregate when sheared. In the past, two mechanisms have been proposed to describe this effect, and it is unclear if both exist. To settle this question, we consider a bidisperse mixture of spheroids of equal volume in a rotating drum, where the two mechanisms are predicted to act in opposite directions. We present evidence that there are two distinct segregation mechanisms driven by relative overstress. Additionally, we showed that, for nonspherical particles, these two mechanisms (kinetic and gravity) can act in different directions leading to a competition between the effects of the two. As a result, the segregation intensity varies nonmonotonically as a function of aspect ratio (AR), and, at specific points, the segregation direction changes for both prolate and oblate spheroids, explaining the surprising segregation reversal previously reported. Consistent with previous results, we found that the kinetic mechanism is dominant for (almost) spherical particles. Furthermore, for moderate aspect ratios, the kinetic mechanism is responsible for the spherical particles' segregation to the periphery of the drum, and the gravity mechanism plays only a minor role. Whereas, at the extreme values of AR, the gravity mechanism notably increases and overtakes its kinetic counterpart.
UR - http://www.scopus.com/inward/record.url?scp=85143905982&partnerID=8YFLogxK
U2 - 10.1103/PhysRevE.106.054614
DO - 10.1103/PhysRevE.106.054614
M3 - Article
C2 - 36559476
AN - SCOPUS:85143905982
SN - 2470-0045
VL - 106
JO - Physical Review E
JF - Physical Review E
IS - 5
M1 - 054614
ER -