title: Direct investigation of anisotropic suspension structure in pressure-driven flow.
abstract: Evidence is presented to show the microstructural anisotropy responsible for normal stress in sheared suspensions. Particle velocimetry is combined with three-dimensional particle locations obtained via confocal microscopy at rest. A range of volume fractions phi and local shear rates gamma are investigated in a weakly Brownian pressure-driven suspension. At high gamma, the pairwise distribution shows a strong probability along the axis of compression similar to observations from Stokesian dynamics simulation at phi=0.32. At the channel center where gamma-->0, the concentrated suspension at phi=0.56 behaves as a confined isotropic fluid.
authors.affiliation: Department of Chemical Engineering, Lehigh University, Bethlehem, Pennsylvania 18015, USA.
authors.forename: C
authors.initials: C
authors.lastname: Gao
authors.forename: S D
authors.initials: SD
authors.lastname: Kulkarni
authors.forename: J F
authors.initials: JF
authors.lastname: Morris
authors.forename: J F
authors.initials: JF
authors.lastname: Gilchrist