title: Universal Scaling Laws for Dense Particle Suspensions in Turbulent Wall-Bounded Flows.
abstract: The macroscopic behavior of dense suspensions of neutrally buoyant spheres in turbulent plane channel flow is examined. We show that particles larger than the smallest turbulence scales cause the suspension to deviate from the continuum limit in which its dynamics is well described by an effective suspension viscosity. This deviation is caused by the formation of a particle layer close to the wall with significant slip velocity. By assuming two distinct transport mechanisms in the near-wall layer and the turbulence in the bulk, we define an effective wall location such that the flow in the bulk can still be accurately described by an effective suspension viscosity. We thus propose scaling laws for the mean velocity profile of the suspension flow, together with a master equation able to predict the increase in drag as a function of the particle size and volume fraction.
authors.affiliation: Laboratory for Aero and Hydrodynamics, Delft University of Technology, Leeghwaterstraat 21, NL-2628 CA Delft, Netherlands.
authors.forename: Pedro
authors.initials: P
authors.lastname: Costa
authors.affiliation: Department of Industrial Engineering, University of Padova, Via Venezia 1, 35131 Padua, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Picano
authors.affiliation: SeRC (Swedish e-Science Research Centre) and Linné FLOW Centre, KTH Mechanics, SE-100 44 Stockholm, Sweden.
authors.forename: Luca
authors.initials: L
authors.lastname: Brandt
authors.affiliation: Laboratory for Aero and Hydrodynamics, Delft University of Technology, Leeghwaterstraat 21, NL-2628 CA Delft, Netherlands.
authors.forename: Wim-Paul
authors.initials: WP
authors.lastname: Breugem