2003/03/31 by Namiko Mitarai, Hiizu Nakanishi
Engineering · Environmental Science · Physics and Astronomy · #Granular flow and fluidized beds #Landslides and related hazards #Particle Dynamics in Fluid Flows #cond-mat.soft #cond-mat.stat-mech
paper · pdf · doi:10.1017/s002211200400881x
published as J. Fluid Mech. 507, 309 (2004). · 25 pages, 15 figures, submitted to J. Fluid Mech.; larger parameter range investigated, discussions revised
arxiv created 2003/09/15 · openalex publication_date 2004/05/12 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
The linear stability of rapid granular flow down a slope under gravity to the longitudinal perturbations is analysed using hydrodynamic equations. It is demonstrated that the steady flow uniform along the flow direction becomes unstable to long-wavelength perturbations longitudinal to the flow direction for certain parameter ranges to form a density wave, in contrast to the finite-wavelength instability for transverse perturbations (Forterre & Pouliquen 2002). It is shown that the instability can be understood as the long-wave instability of kinematic waves in a quasi-one-dimensional system. The results are compared with our previous molecular dynamics simulations (Mitarai & Nakanishi 2001), where spontaneous density wave formation was found.