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Lifting off a solid sphere from a flat bottom by laminar fluid flow
Author(s) -
Wang Chao,
Wang Hanbin,
Zhang Kun,
Li Zhipeng,
Gao Zhengming,
Derksen Jos J.
Publication year - 2020
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.16886
Subject(s) - laminar flow , mechanics , particle (ecology) , flow (mathematics) , magnetosphere particle motion , classical mechanics , flow visualization , physics , impeller , geology , oceanography , quantum mechanics , magnetic field
We perform quantitative visualization experiments on the vertical ( z ‐direction) motion of a spherical solid particle being lifted off a horizontal flat bottom due to laminar fluid flow generated by a revolving impeller. Describing the observed motion of the particle in terms of a constant vertical hydrodynamic force overcoming gravity and the lubrication force has limited success. For this reason, we hypothesize that the hydrodynamic force on the particle quickly increases with its distance from the bottom. This hypothesis is supported by detailed numerical simulations of the flow around the particle. Integrating the equation of motion of the sphere with the vertical hydrodynamic force as a linear function of z derived from simulations provides an adequate description of the experimentally observed vertical motion of the particle.