Cargando…

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

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. Simil...

Descripción completa

Detalles Bibliográficos
Autores principales: Pacheco-Vázquez, F., Ruiz-Suárez, J.C.
Formato: Texto
Lenguaje:English
Publicado: Nature Publishing Group 2010
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3065908/
https://www.ncbi.nlm.nih.gov/pubmed/21119636
http://dx.doi.org/10.1038/ncomms1123
Descripción
Sumario: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.