Rice Pile Experiments
Experiments on stochastic avalanching of rice pile as analogue to sediment transport fluctuations. The rice pile is formed in a narrow chamber (width ≈ 2 cm) separated by two flat glass walls (height, width ≈ 30 cm). Rice grains are fed by a custom-built screw feeder controlled by Microsoft VBA script determining rate of rotation of screw feeder (which increases linearly with feed rate of grains). Resulting flux of rice grains out of pile is determined by scale below outlet which records weight every one second. Flux can be determined by differences in scale weight between time steps. A vacuum set to blower mode periodically clears particles from the scale.
Two types of experiments were performed:
- Steady feed (constant rate of particle additions to rice pile).
- Unsteady feed (sinusoidal, sawtooth, or square wave feeding of particles to rice pile). Different amplitudes and periods of fluctuations among experiments.
Excel spreadsheet (included as internet resource below) describes parameters for all experiments. "Raw data" folder includes timeseries (recorded or interpolated to 1 Hz) of cumulative mass (in grams) of rice particles on weigh scale. Data need to be "cleaned" to remove signal of periodic vacuum blower used to remove rice particles.
More information is available here: http://sedexp.net/experiment/one-dimensional-rice-pile-avalanche
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