When particles pass through an orifice, jamming can occur. The question is whether a jammed struc... more When particles pass through an orifice, jamming can occur. The question is whether a jammed structure can be considered a new state of matter, and if the flow behaves differently when approaching jamming. An experiment, consisting of a silo filled with grains and an orifice at the base, is presented here. The jamming probability is measured, and it is shown that above a certain orifice size no jamming can occur. A power law divergence is found when that value is approached. Besides, the flow rate is different for small and large orifices. For large orifices, the Beverloo equation states that the flow depends on the diameter to the 5/2 power. But this relation breaks down for small orifices. A new functional dependence is proposed, in agreement with the experiments and the numerical simulations. Furthermore, the statistical analysis of the fluctuations for small orifices shows anomalous behavior.
When particles pass through an orifice, jamming can occur. The question is whether a jammed struc... more When particles pass through an orifice, jamming can occur. The question is whether a jammed structure can be considered a new state of matter, and if the flow behaves differently when approaching jamming. An experiment, consisting of a silo filled with grains and an orifice at the base, is presented here. The jamming probability is measured, and it is shown that above a certain orifice size no jamming can occur. A power law divergence is found when that value is approached. Besides, the flow rate is different for small and large orifices. For large orifices, the Beverloo equation states that the flow depends on the diameter to the 5/2 power. But this relation breaks down for small orifices. A new functional dependence is proposed, in agreement with the experiments and the numerical simulations. Furthermore, the statistical analysis of the fluctuations for small orifices shows anomalous behavior.
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