Particle focusing in a wavy channel
Name
particle-focusing-in-a-wavy-channel.pdf
Size
5.3 MB
Format
Adobe PDF
Checksum (MD5)
8704e1d86fec81f755b8a44d50068836
Author(s)
Mao, Xinyu
Bischofberger, Irmgard
Hosoi, A.E.
Date Issued
August 7, 2023
Journal
Journal of Fluid Mechanics
Publisher
Cambridge University Press
Citation
Mao X, Bischofberger I, Hosoi AE. Particle focusing in a wavy channel. Journal of Fluid Mechanics.
Version
Final published version
Abstract
It is known that inertial lift forces can lead to particle focusing in channel flows; yet oscillatory straining effects have also been suggested as a mechanism for particle focusing in wavy channels. To explore the synergy between these two mechanisms, we analytically and experimentally investigate the focusing behaviour of rigid neutrally buoyant particles in a wavy channel. We decompose the particle-free channel flow into a primary Poiseuille flow and secondary eddies induced by the waviness. We calculate the perturbation of the particle on the particle-free flow and the resulting lateral lift force exerted on the particle using the method of matched asymptotic expansions. This yields a zeroth-order lift force arising from the Poiseuille flow and a first-order lift force due to the waviness of the channel. We further incorporate the inertial lift force into the Maxey–Riley equation and simulate particle trajectories in wavy channels. The interactions between the zeroth-order lift force and the particle-free flow largely determine the focusing locations. Experiments in wavy channels with varying amplitudes at channel Reynolds numbers ranging from 5 to 250 are consistent with the predictions of the focusing locations, which are mainly governed by the channel Reynolds number as well as the competition between the inertial lift and the oscillatory straining effects.
Subjects
Mechanical Engineering
Mechanics of Materials
Condensed Matter Physics
Applied Mathematics
MIT Department
Massachusetts Institute of Technology. Department of Mechanical Engineering
Massachusetts Institute of Technology. Department of Mathematics
Terms of Use
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
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DOI of Published Version
https://doi.org/10.1017/jfm.2023.558
