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Cooperative dynamics in the penetration of a group of intruders in a granular medium.

ABSTRACT: An object moving in a fluid experiences a drag force that depends on its velocity, shape and the properties of the medium. From this simplest case to the motion of a flock of birds or a school of fish, the drag forces and the hydrodynamic interactions determine the full dynamics of the system. Similar drag forces appear when a single projectile impacts and moves through a granular medium, and this case is well studied in the literature. On the other hand, the case in which a group of intruders impact a granular material has never been considered. Here, we study the simultaneous penetration of several intruders in a very low-density granular medium. We find that the intruders move through it in a collective way, following a cooperative dynamics, whose complexity resembles flocking phenomena in living systems or the movement of reptiles in sand, wherein changes in drag are exploited to efficiently move or propel.

SUBMITTER: Pacheco-Vazquez F

PROVIDER: S-EPMC3065908 | biostudies-other | 2010

REPOSITORIES: biostudies-other

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Cooperative dynamics in the penetration of a group of intruders in a granular medium.

Pacheco-Vázquez F F Ruiz-Suárez J C JC

Nature communications 20101123

An object moving in a fluid experiences a drag force that depends on its velocity, shape and the properties of the medium. From this simplest case to the motion of a flock of birds or a school of fish, the drag forces and the hydrodynamic interactions determine the full dynamics of the system. Similar drag forces appear when a single projectile impacts and moves through a granular medium, and this case is well studied in the literature. On the other hand, the case in which a group of intruders i ...[more]

PMID: 21119636

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