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Soutenance de Louison Thorens

Unstable drainage of frictional fluids and magnetic control of the mechanical behavior of confined granular media
When Nov 17, 2021
from 01:15 to 02:00
Where Oslo
Contact Name Louison Thorens
Attendees Louison Thorens
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Résumé

The transport of immersed grains in confined media relevant for many industrial and natural situations highlights the complex interaction between capillary and granular stress.
In this thesis, we have studied the triggering of a bulldozing instability, leading to the formation of granular plugs during the slow drainage of a frictional fluid, mixture of a liquid and grains sedimented in a capillary. We could reveal a new unstable regime leading to the periodic formation of dunes. Furthermore, we have developed an original method to control the frictional interactions at the origin of this bulldozing instability, by using ferromagnetic particles: submitted to a magnetic field, they acquire a magnetic moment, leading to tunable interactions of pairs of magnetic dipoles. We demonstrated the emergence of a radial force along the walls of the container, whose amplitude and direction are determined by the applied magnetic field. This "magnetic Janssen effect" allows to control the apparent mass of the granular column, paving the way towards the design of granular meta-materials, whose mechanical (un)jamming properties can be remotely controlled or even programmed.

Soutenance

La soutenance a lieu à Oslo et sera disponible en visioconférence.

Louison donnera également un séminaire au laboratoire le 30 novembre 2021 à 11h en salle des thèses pour présenter ses résultats.