IFLYSIB   05383
INSTITUTO DE FISICA DE LIQUIDOS Y SISTEMAS BIOLOGICOS
Unidad Ejecutora - UE
artículos
Título:
Role of vibrations in the jamming and unjamming of grains discharging from a silo
Autor/es:
C. MANKOC; A. GARCIMART├ŹN; I. ZURIGUEL; D. MAZA; L. A. PUGNALONI
Revista:
PHYSICAL REVIEW E - STATISTICAL PHYSICS, PLASMAS, FLUIDS AND RELATED INTERDISCIPLINARY TOPICS
Editorial:
The American Physical Society
Referencias:
Año: 2009 vol. 80 p. 113091 - 113097
ISSN:
1063-651X
Resumen:
We present experimental results of the jamming of non-cohesive particles discharged from a fat bottomed silo subjected to vertical vibration. When the exit orifice is only a few grain diameters wide, the flow can be arrested due to the formation of blocking arches. Hence, an external excitation is needed to resume the flow. The use of a continuous gentle vibration is a usual technique to ease the flow in such situations. Even though jamming is less frequent, it is still an issue in vibrated silos. There are, in principle, two possible mechanisms through which vibrations may facilitate the flow: (i) a decrease in the probability of the formation of blocking arches, and (ii) the breakage of blocking arches once they have been formed. By measuring the time intervals inside an avalanche during which no particles flow through the outlet, we are able to estimate the probability of breaking a blocking arch by vibrations. The result agrees with the prediction of a bivariate probabilistic model in which the formation of blocking arches is equally probable in vibrated and non-vibrated silos. This indicates that the second aforementioned mechanism is the main responsible for improving the flowability in gently vibrated silos.