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Drag of a cylinder moving near a wall in a yield stress fluid
Author(s) -
Ouattara Ziemihori,
Jay Pascal,
Blésès Didier,
Magnin Albert
Publication year - 2018
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.16220
Subject(s) - drag , mechanics , viscoplasticity , yield (engineering) , viscosity , newtonian fluid , cylinder , materials science , inertia , stress (linguistics) , non newtonian fluid , drag coefficient , rheology , parasitic drag , classical mechanics , thermodynamics , physics , composite material , mathematics , constitutive equation , geometry , finite element method , linguistics , philosophy
The drag of a cylindrical obstacle moving at a constant velocity in a yield stress fluid close to a wall is studied experimentally and numerically. The wall influence has been explored for gap values between the cylinder of diameter D and the wall ranging from 0.01D to 100D, which corresponds, respectively, to hydrodynamic lubrication and to unconfined domain conditions. A model yield stress fluid (Carbopol gel) is used in the experiments. The viscous and plastic drag coefficients have been calculated and measured as depending on the Oldroyd number, in conditions where the yield stress effects are more important than those of viscosity and the inertia negligible. We have performed experimental and numerical validations in the Newtonian case and provided more specifically comparisons of our measured data on yield stress materials with those resulting from viscoplastic flow simulations. © 2018 American Institute of Chemical Engineers AIChE J , 64: 4118–4130, 2018