Direct verification of the lubrication force on a sphere travelling through a viscous film upon approach to a solid wall

Handle URI:
http://hdl.handle.net/10754/561535
Title:
Direct verification of the lubrication force on a sphere travelling through a viscous film upon approach to a solid wall
Authors:
Marston, Jeremy; Wang, Yong; Thoroddsen, Sigurdur T. ( 0000-0001-6997-4311 )
Abstract:
Experiments were performed to observe the motion of a solid sphere approaching a solid wall through a thin layer of a viscous liquid. We focus mainly on cases where the ratio of the film thickness, ℘, to the sphere diameter, D, is in the range 0.03 ℘</D < 0.09 and the Stokes number, St, a measure of the sphere inertia to viscous forces, is below a critical level Stc so that the spheres do not rebound and escape from the liquid layer. This provides us with the scope to verify the force acting on the sphere, derived from lubrication theory. Using high-speed video imaging we show, for the first time, that the equations of motion based on the lubrication approximation correctly describe the deceleration of the sphere when St < Stc. Furthermore, we show that the penetration depth at which the sphere motion is first arrested by the viscous force, which decreases with increasing Stokes number, matches well with theoretical predictions. An example for a shear-thinning liquid is also presented, showing that this simple set-up may be used to deduce the short-time dynamical behaviour of non-Newtonian liquids. © 2010 Cambridge University Press.
KAUST Department:
Physical Sciences and Engineering (PSE) Division; Mechanical Engineering Program; High-Speed Fluids Imaging Laboratory
Publisher:
Cambridge University Press (CUP)
Journal:
Journal of Fluid Mechanics
Issue Date:
21-May-2010
DOI:
10.1017/S0022112010001266
Type:
Article
ISSN:
00221120
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division; Mechanical Engineering Program

Full metadata record

DC FieldValue Language
dc.contributor.authorMarston, Jeremyen
dc.contributor.authorWang, Yongen
dc.contributor.authorThoroddsen, Sigurdur T.en
dc.date.accessioned2015-08-02T09:13:40Zen
dc.date.available2015-08-02T09:13:40Zen
dc.date.issued2010-05-21en
dc.identifier.issn00221120en
dc.identifier.doi10.1017/S0022112010001266en
dc.identifier.urihttp://hdl.handle.net/10754/561535en
dc.description.abstractExperiments were performed to observe the motion of a solid sphere approaching a solid wall through a thin layer of a viscous liquid. We focus mainly on cases where the ratio of the film thickness, ℘, to the sphere diameter, D, is in the range 0.03 ℘</D < 0.09 and the Stokes number, St, a measure of the sphere inertia to viscous forces, is below a critical level Stc so that the spheres do not rebound and escape from the liquid layer. This provides us with the scope to verify the force acting on the sphere, derived from lubrication theory. Using high-speed video imaging we show, for the first time, that the equations of motion based on the lubrication approximation correctly describe the deceleration of the sphere when St < Stc. Furthermore, we show that the penetration depth at which the sphere motion is first arrested by the viscous force, which decreases with increasing Stokes number, matches well with theoretical predictions. An example for a shear-thinning liquid is also presented, showing that this simple set-up may be used to deduce the short-time dynamical behaviour of non-Newtonian liquids. © 2010 Cambridge University Press.en
dc.publisherCambridge University Press (CUP)en
dc.titleDirect verification of the lubrication force on a sphere travelling through a viscous film upon approach to a solid wallen
dc.typeArticleen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.contributor.departmentMechanical Engineering Programen
dc.contributor.departmentHigh-Speed Fluids Imaging Laboratoryen
dc.identifier.journalJournal of Fluid Mechanicsen
dc.contributor.institutionA-STAR Institute of Chemical and Engineering Sciences, 1 Pesek Road, Jurong Island, Singapore 627833, Singaporeen
dc.contributor.institutionDepartment of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117576, Singaporeen
kaust.authorMarston, Jeremyen
kaust.authorThoroddsen, Sigurdur T.en
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