Recirculation cells for granular flow in cylindrical rotating tumblers

Abstract : To better understand the velocity field and flowing layer structure, we have performed a detailed discrete element method study of the flow of monodisperse particles in a partially filled three-dimensional cylindrical rotating tumblers. Similar to what occurs near the poles in spherical and conical tumblers, recirculation cells (secondary flows) develop near the flat endwalls of a cylindrical tumbler in which particles near the surface drift axially toward the endwall, while particles deeper in the flowing layer drift axially toward the midlength of the tumbler. Another recirculation cell with the opposite sense develops next to each endwall recirculation cell, extending to the midlength of the tumbler. For a long enough tumbler, each endwall cell is about one quarter of the tumbler diameter in length. Endwall cells are insensitive to tumbler length and relatively insensitive to rotation speed (so long as the flowing layer remains flat and continuously flowing) or fill level (from 25% to 50% full). However, for shorter tumblers (0.5 to 1.0 length/diameter aspect ratio) the endwall cell size does not change much, while center cells reduce their size and eventually disappear for the shortest tumblers. For longer tumblers (length/diameter aspect ratio larger than 2), a stagnation zone appears in between the central cells. These results provide insight into the mixing of monodisperse particles in rotating cylindrical tumblers as well as the frictional effects of the tumbler endwalls.
Type de document :
Article dans une revue
Physical Review E , American Physical Society (APS), 2018, 97 (5), pp.052904. 〈10.1103/PhysRevE.97.052904〉
Liste complète des métadonnées

https://hal.archives-ouvertes.fr/hal-01875642
Contributeur : M2p2 Conf <>
Soumis le : lundi 17 septembre 2018 - 16:00:41
Dernière modification le : mardi 18 septembre 2018 - 01:14:13

Identifiants

Collections

Citation

Umberto D'Ortona, Nathalie Thomas, Richard Lueptow. Recirculation cells for granular flow in cylindrical rotating tumblers. Physical Review E , American Physical Society (APS), 2018, 97 (5), pp.052904. 〈10.1103/PhysRevE.97.052904〉. 〈hal-01875642〉

Partager

Métriques

Consultations de la notice

29