Schematic diagram of the force components considered in a soft-sphere contact model.
Schematic diagram of the flume facility which can be fixed to an inclination angle, Θ, from the horizontal. Compartments A, B, and C represent the reservoir, the flow section, and the deposit basin, respectively, and two high-speed digital cameras were installed to record the experiments from the flume lateral side. Only section A and camera 1 were employed in this work.
Normalized projection area of the bulk remained in the reservoir, A(t)/A 0, during granular avalanches at three reservoir inclination angles, Θ = 19°, 24°, and 29°. Each line is the mean of three repeated experiments with the corresponding standard deviation marked.
Trajectories of individual spheres that moved with an avalanching bulk down the reservoir at Θ = 19°. The tracking time is 0.3 s and the gray open circles in the background represent the original packing.
Comparison of the simulated temporal profile of the normalized projection area using one set of surface friction coefficients (indicated on the plot) to those measured in the experiments at three reservoir inclination angles.
(a) Rear tracers, (b) central tracers, (c) front tracers: Comparison of the simulated and the measured trajectories of individual spheres moving next to the reservoir wall in a dry granular avalanche at Θ = 19°: experiment, ○ ; simulation, ——. The dashed line indicates the original packing surface.
Collective particle trajectories at different stages, (a) t = 0–0.1 s, (b) t = 0.18–0.24 s, (c) t = 0.34–0.4 s, during an actual (left) and a simulated (right) avalanche down a slope at Θ = 19°.
Illustration of an average box (dashed line) and its contained particle information (used in Eq. (3) ).
Comparison of the simulated (in symbols) and the measured instantaneous bulk velocity profile at different times after opening the gate: (a) 0.1 s, (b) 0.2 s, (c) 0.3 s. The velocity was examined at three streamwise locations from the reservoir upstream corner at x = 8, 16, and 24 cm.
Comparison of the instantaneous bulk velocities from the experimental mean and three simulations at different times and positions for the avalanche down Θ = 19°.
Comparison of the instantaneous bulk velocities from the experimental mean and three simulations at different times and positions for the avalanche down Θ = 24°.
Comparison of the instantaneous bulk velocities from the experimental mean and three simulations at different times and positions for the avalanche down Θ = 29°.
Properties of materials employed in the experiments.
Article metrics loading...
Full text loading...