title: Local shear stress and its correlation with local volume fraction in concentrated non-Brownian suspensions: lattice Boltzmann simulation.
abstract: The local shear stress of non-Brownian suspensions was investigated using the lattice Boltzmann method coupled with the smoothed profile method. Previous studies have only focused on the bulk rheology of complex fluids because the local rheology of complex fluids was not accessible due to technical limitations. In this study, the local shear stress of two-dimensional solid particle suspensions in Couette flow was investigated with the method of planes to correlate non-Newtonian fluid behavior with the structural evolution of concentrated particle suspensions. Shear thickening was successfully captured for highly concentrated suspensions at high particle Reynolds number, and both the local rheology and local structure of the suspensions were analyzed. It was also found that the linear correlation between the local particle stress and local particle volume fraction was dramatically reduced during shear thickening. These results clearly show how the change in local structure of suspensions influences the local and bulk rheology of the suspensions.
authors.affiliation: School of Chemical and Biological Engineering, Institute of Chemical Process, Seoul National University, Seoul, 151-744 Korea.
authors.forename: Young Ki
authors.initials: YK
authors.lastname: Lee
authors.affiliation: School of Chemical and Biological Engineering, Institute of Chemical Process, Seoul National University, Seoul, 151-744 Korea.
authors.forename: Kyung Hyun
authors.initials: KH
authors.lastname: Ahn
authors.affiliation: School of Chemical and Biological Engineering, Institute of Chemical Process, Seoul National University, Seoul, 151-744 Korea.
authors.forename: Seung Jong
authors.initials: SJ
authors.lastname: Lee