On the role of inertia in channel flows of finite-size neutrally buoyant particles

Ali Yousefi*, Pedro Costa, Francesco Picano, Luca Brandt

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

We consider suspensions of finite-size neutrally buoyant rigid spherical particles in channel flow and investigate the relevance of different momentum transfer mechanisms and the relation between the local particle dynamics and the bulk flow properties in the highly inertial regime. Interface-resolved simulations are performed in the range of Reynolds numbers and solid volume fractions. The Lagrangian particle statistics show that pair interactions are highly inhomogeneous and dependent on the distance from the wall: in their vicinity, the underlying mean shear drives the pair interactions, while a high degree of isotropy, dictated by more frequent collisions, characterizes the core region. Analysis of the momentum balance reveals that while the particle-induced stresses govern the dynamics in dense conditions, and moderate Reynolds numbers, <![CDATA[$Re, the turbulent stresses take over at higher Reynolds numbers. This behaviour is associated with a reduced particle migration toward the channel core, which decreases the importance of the particle-induced stress and increases the turbulent activity. Our results indicate that Reynolds stresses and the associated velocity fluctuations, characteristics of near-wall turbulence, prevail at high inertia over the resistance to deformation presented by the particles for volume fractions lower than 30 %.

Original languageEnglish
Article number2201078
JournalJournal of Fluid Mechanics
Volume955
DOIs
Publication statusPublished - 25 Jan 2023

Bibliographical note

Publisher Copyright:
© The Author(s), 2023. Published by Cambridge University Press.

Other keywords

  • particle/fluid flow
  • suspensions

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