Slow motion of a sphere towards a plane through confined non-Newtonian fluid
Langue
en
Article de revue
Ce document a été publié dans
Journal of Non-Newtonian Fluid Mechanics. 2012-01, vol. 167-168, p. 38-45
Elsevier
Résumé en anglais
The time needed for the contact of two spheres or a sphere with a rigid plane is mainly controlled by the hydrodynamic drainage of the film located in the gap as long as its thickness is out of range of the Van der Waals ...Lire la suite >
The time needed for the contact of two spheres or a sphere with a rigid plane is mainly controlled by the hydrodynamic drainage of the film located in the gap as long as its thickness is out of range of the Van der Waals interactions. In fact, this time controls the dynamics of aggregation of concentrated dispersions. This fundamental problem has an exact solution in Newtonian fluid which has been used to confirm the validity of the numerical dynamic mesh method employed in this geometrically unsteady problem. Following this validation, we applied it to calculate the correction factor of the drag undergone by a sphere approaching a plane, at constant Reynolds number, in a cylindrical tube filled with a non-Newtonian fluid having negligible viscoelastic component and roughly behaving as a power-law fluid. After a justification for using this useful model, we studied the influence of the lateral confinement on the frontal correction factor of the drag. In the lubrication limit, we recall the asymptotic solution of Rodin to this problem in lateral unbounded power law fluid. The comparison of both asymptotical and numerical results confirms their validity. The results obtained in this study may find an application to Dynamic Surface Force Apparatus for nanorheology.< Réduire
Mots clés en anglais
Sphere towards a plane
Non-Newtonian fluids
Frontal hydrodynamic interactions
Lubrication
Aggregation
Drainage film
Origine
Importé de halUnités de recherche