title: Anomalous diffusion for inertial particles under gravity in parallel flows.
abstract: We investigate the bounds between normal or anomalous effective diffusion for inertial particles transported by parallel flows. The infrared behavior of the fluid kinetic-energy spectrum, i.e., the possible presence of long-range spatiotemporal correlations, is modeled as a power law by means of two parameters, and the problem is studied as a function of these latter. Our results, obtained in the limit of weak relative inertia, extend well-known results for tracers and apply to particles of any mass density, subject to gravity and Brownian diffusion. We consider both steady and time-dependent flows, and cases of both vanishing and finite particle sedimentation.
authors.affiliation: Laboratoire de Mécanique, Modélisation et Procédés Propres, CNRS UMR 7340, Aix-Marseille Université, Ecole Centrale Marseille, 38 rue Frédéric Joliot-Curie, 13451 Marseille cedex 13, France.
authors.forename: Marco
authors.initials: M
authors.lastname: Martins Afonso
mesh_terms: D000054:Acceleration; D003102:Colloids / Q000737:chemistry*; D003198:Computer Simulation; D004058:Diffusion; D006112:Gravitation; D008956:Models, Chemical; D010316:Particle Size; D012212:Rheology / Q000379:methods*; D014783:Viscosity
chemical_list: D003102:Colloids