Orateur
Description
Although multiphase flows are ubiquitous in natural and industrial systems, the comprehension of the physical mechanisms at stake is still a challenge. In particular, the link between the processes at the microscale -- grain size, shape, asperities -- and the behavior at larger scale (particle suspension, transport, emergence of instabilities\ldots) remains unknown. Based on laboratory experiments, we investigate the dynamics of a confined granular layer submitted to a localized fluid injection. A suspension results from the competition between particle entrainment and sedimentation. In a given range of parameters and for different experimental configurations, the system exhibits puzzling self-induced oscillations and unexpected, violent particle resuspension. The importance of such phenomena will be discussed in regards to geophysical and environmental applications.
