INSTITUTO DE FISICA DE LIQUIDOS Y SISTEMAS BIOLOGICOS
Unidad Ejecutora - UE
Pressure independence of granular flow through an aperture
M. A. AGUIRRE; J. G. GRANDE; A. CALVO; L. A. PUGNALONI; J. C. GÉMINARD
PHYSICAL REVIEW LETTERS
AMER PHYSICAL SOC
Año: 2010 vol. 104 p. 2380021 - 23800214
We experimentally demonstrate that the ﬂow rate of granular material through an aperture is controlled by the exit velocity imposed on the particles and not by the pressure at the base, contrary to what is often assumed in previous work. This result is achieved by studying the discharge process of a dense packing of monosized disks through an oriﬁce. The ﬂow is driven by a conveyor belt. This two-dimensional horizontal setup allows us to independently control the velocity at which the disks escape the horizontal silo and the pressure in the vicinity of the aperture. The ﬂow rate is found to be proportional to the belt velocity, independent of the amount of disks in the container and, thus, independent of the pressure in the outlet region. In addition, this speciﬁc conﬁguration makes it possible to get information on the system dynamics from a single image of the disks that rest on the conveyor belt after the discharge.