Numerical Study of the Sedimentation of Spheroidal Particles

Abstract

The gravity-driven motion of rigid particles in a viscous fluid is relevant in many natural and industrial processes, yet this has mainly been investigated for spherical particles. We therefore consider the sedimentation of non-spherical (spheroidal) isolated and particle pairs in a viscous fluid via numerical simulations using the Immersed Boundary Method. The simulations performed here show that the critical Galileo number for the onset of secondary motions decreases as the spheroid aspect ratio departs from 1. Above this critical threshold, oblate particles perform a zigzagging motion whereas prolate particles rotate around the vertical axis while having their broad side facing the falling direction. Instabilities of the vortices in the wake follow when farther increasing the Galileo number. We also study the drafting-kissing-tumbling associated with the settling of particle pairs. We find that the interaction time increases significantly for non-spherical particles and, more interestingly, spheroidal particles are attracted from larger lateral displacements. This has important implications for the estimation of collision kernels and can result in increasing clustering in suspensions of sedimenting spheroids.

References in corpus (6)

• An Immersed Boundary Method with Direct Forcing for the Simulation of Particulate Flows
• Turbulent channel flow of dense suspensions of neutrally-buoyant spheres
• Sedimentation of a dilute suspension of rigid spheres at intermediate Galileo numbers: the effect of clustering upon the particle motion
• Collision model for fully-resolved simulations of flows laden with finite-size particles
• Sedimentation of finite-size spheres in quiescent and turbulent environments
• The effect of particle density in turbulent channel flow laden with finite size particles in semi-dilute conditions

Cited by in corpus (23)

• Inertial migration of spherical and oblate particles in straight ducts
• Drag reduction in turbulent channel flow laden with finite-size oblate spheroids
• Computational modeling of multiphase viscoelastic and elastoviscoplastic flows
• Three-dimensional dynamics of a pair of deformable bubbles rising initially in line. Part 1: Moderately inertial regimes
• Statistical model for the orientation of non-spherical particles settling in turbulence
• Theory for the effect of fluid inertia on the orientation of a small particle settling in turbulence
• A Review on Contact and Collision Methods for Multi-body Hydrodynamic problems in Complex Flows
• A collision model for DNS with ellipsoidal particles in viscous fluid
• Clustering and increased settling speed of oblate particles at finite Reynolds number
• On the clustering of low-aspect-ratio oblate spheroids settling in ambient fluid
• Numerical simulations of elastic capsules with nucleus in shear flow
• Strong alignment of prolate ellipsoids in Taylor-Couette flow
• Orientation instability of settling spheroids in a linearly density stratified fluid
• Turbulent channel flow of finite-size spherical particles with viscous hyper-elastic walls
• Metaball-Imaging Discrete Element Lattice Boltzmann Method for fluid-particle system of complex morphologies with settling case study
• Prolate spheroids settling in a quiescent fluid: clustering, microstructures and collisions
• Dynamics of finite-size spheroids in turbulent flow: the roles of flow structures and particle boundary layers
• Numerical study on turbulence modulation of finite-size particles in plane-Couette flow
• Three-dimensional sedimentation patterns of two interacting disks in a viscous fluid
• A multiple-time-step integration algorithm for particle-resolved simulation with physical collision time
• Regimes of heat transfer in particle suspensions
• Settling behaviour of thin curved particles in quiescent fluid and turbulence
• Turbulence modulation in channel flow of finite-size spheroidal particles