2000/12/19 by L. Bocquet, Lydéric Bocquet, Wolfgang Losert +4 · 255 citations
Engineering · Environmental Science · Physics and Astronomy · #Classical mechanics #Couette flow #Flow (mathematics) #Granular flow and fluidized beds #Granular material #Landslides and related hazards #Materials science #Mechanics #Newtonian fluid #Physics #Rheology #Shear (geology) #Shear flow #Shear rate #Shear velocity #Soil and Unsaturated Flow #Thermodynamics #Turbulence #cond-mat.stat-mech
paper · pdf · doi:10.1103/physreve.65.011307
published in Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics 65(1), 011307 (American Physical Society) · 19 pages, 11 figures
arxiv created 2000/12/19 · openalex publication_date 2001/12/21 · arxiv updated 2021/05/26 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We analyze the main features of granular shear flow through experimental measurements in a Couette geometry and a comparison to a locally Newtonian, continuum model of granular flow. The model is based on earlier hydrodynamic models, adjusted to take into account the experimentally observed coupling between fluctuations in particle motion and mean-flow properties. Experimentally, the local velocity fluctuations are found to decrease more slowly with distance from the shear surface than the velocity. This can be explained by an effective viscosity that diverges more rapidly as the random-close-packing density is approached than is predicted by Enskog theory for dense hard-sphere systems. Experiment and theory are in good agreement, especially for the following key features of granular flow: The flow is confined to a small shear band, fluctuations decay approximately exponentially away from the sheared wall, and the shear stress is approximately independent of the shear velocity. The functional forms of the velocity and fluctuation profiles predicted by the model agree with the experimental results.