Research Data Leeds Repository

Citation

Moseley, Katherine and Fairweather, Michael and Harbottle, David (2019) Data associated with "Settling dynamics of two identical vertical aligned spheres in a thixotropic fluid.". University of Leeds. [Dataset] https://doi.org/10.5518/708

Dataset description

Despite the great relevance of particle dynamics in non-Newtonian fluids, particles settling in non-Newtonian fluids has received limited scientific attention. The simple case of two vertically aligned spheres settling in a thixotropic xanthan fluid is considered using solutions of xanthan + glycerol + water and 0.75 mm radius stainless steel spheres. Chaining phenomenon is observed where the trailing sphere velocity is increased due to a corridor of reduced viscosity created by the leading sphere. Our experimental methods are first validated against a Newtonian fluid of glycerol + water in which the sphere velocities remained equal. Using the fluid velocity induced by a single sphere, the two sphere velocities are approximated by Faxén’s first law. In a non-Newtonian (thixotropic) xanthan fluid, a viscosity ratio is introduced to account for the reduced fluid viscosity encountered by the trailing sphere due to the slow structure recovery after shear thinning. The viscosity ratio is an exponential decay function dependent on the time between spheres normalised by the fluid recovery time, a parameter which is experimentally determined. When the sphere-sphere separation is large, the viscosity ratio tends towards unity. The predicted settling velocities show good agreement with experimental data.

Keywords:	Thixotropy, Shear thinning, Particle, Sedimentation, Particle image, velocimetry
Subjects:	H000 - Engineering > H100 - General engineering > H140 - Mechanics > H141 - Fluid mechanics
Divisions:	Faculty of Engineering and Physical Sciences > School of Chemical and Process Engineering
Related resources:	Location Type https://doi.org/10.1016/j.jnnfm.2019.104146 Publication https://eprints.whiterose.ac.uk/150312/ Publication
License:	Creative Commons Attribution 4.0 International (CC BY 4.0)
Date deposited:	21 Aug 2019 10:42
URI:	https://archive.researchdata.leeds.ac.uk/id/eprint/563
Additional details Additional details Creators or authors: Creators ORCID Other ID Email Primary affiliation Primary affiliation ID Primary affiliation ID type Secondary affiliation Secondary affiliation ID Secondary affiliation ID type Moseley, Katherine University of Leeds https://ror.org/024mrxd33 ror Fairweather, Michael https://orcid.org/0000-0001-7568-2235 University of Leeds https://ror.org/024mrxd33 ror Harbottle, David https://orcid.org/0000-0002-0169-517X University of Leeds https://ror.org/024mrxd33 ror Type of data: Dataset Research funders: EPSRC Grant numbers: EP/L015390/1 Publication date: 2019 Resource language: English Metadata language: English Publisher: University of Leeds Contact email: d.harbottle@leeds.ac.uk Last Modified: 17 Dec 2024 14:15

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