title: Eddy viscosity in dense granular flows.
abstract: We present a seminal set of experiments on dense granular flows in the stadium shear geometry. The advantage of this geometry is that it produces steady shear flow over large deformations, in which the shear stress is constant. The striking result is that the velocity profiles exhibit an S shape, and are not linear as local constitutive laws would predict. We propose a model that suggests this is a result of wall perturbations which span through the system due to the nonlocal behavior of the material. The model is analogous to that of eddy viscosity in turbulent boundary layers, in which the distance to the wall is introduced to predict velocity profiles. Our findings appear pivotal in a number of experimental and practical situations involving dense granular flows next to a boundary. They could further be adapted to other similar materials such as dense suspensions, foams, or emulsions.
authors: Particles and Grains Laboratory, School of Civil Engineering, The University of Sydney, Sydney, New South Wales 2006, Australia.
authors: T
authors: T
authors: Miller
authors: P
authors: P
authors: Rognon
authors: B
authors: B
authors: Metzger
authors: I
authors: I
authors: Einav
mesh_terms: D000465:Algorithms; D008422:Materials Testing / Q000379:methods*; D008956:Models, Chemical; D010969:Plastics / Q000737:chemistry; D033081:Shear Strength; D014783:Viscosity
chemical_list: D010969:Plastics