A constitutive equation for concentrated suspensions that accounts for shear-induced particle migration

Journal Article · Wed Jan 01 04:00:00 EST 1992 · Physics of Fluids A; (United States)

DOI:https://doi.org/10.1063/1.858498· OSTI ID:5551805

Phillips, R J; Armstrong, R C; Brown, R A ^[1]; Graham, A L; Abbott, J R ^[2]

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1. Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)
2. Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

A constitutive equation for computing particle concentration and velocity fields in concentrated monomodal suspensions is proposed that consists of two parts: a Newtonian constitutive equation in which the viscosity depends on the local particle volume fraction and a diffusion equation that accounts for shear-induced particle migration. Particle flux expressions used to obtain the diffusion equation are derived by simple scaling arguments. Predictions are made for the particle volume fraction and velocity fields for steady Couette and Poiseuille flow, and for transient start-up of steady shear flow in a Couette apparatus. Particle concentrations for a monomodal suspension of polymethyl methacrylate spheres in a Newtonian solvent are measured by nuclear magnetic resonance (NMR) imaging in the Couette geometry for two particle sizes and volume fractions. The predictions agree remarkably well with the measurements for both transient and steady-state experiments as well as for different particle sizes.

• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 5551805
• Journal Information: Physics of Fluids A; (United States), Journal Name: Physics of Fluids A; (United States) Vol. 4:1; ISSN 0899-8213; ISSN PFADE
• Country of Publication: United States
• Language: English

Related Subjects

665000* -- Physics of Condensed Matter-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CARBOXYLIC ACID SALTS
CONCENTRATION RATIO
COUETTE FLOW
DIFFUSION
DISPERSIONS
FLUID FLOW
MAGNETIC RESONANCE
METHACRYLATES
MIGRATION
MULTIPHASE FLOW
NUCLEAR MAGNETIC RESONANCE
PARTICLES
RESONANCE
SCALING
SPHERES
SUSPENSIONS
VISCOUS FLOW