Continuum modeling of particulate flows in geophysics: from fluid bed shear stress driven transport to gravity-driven flows
| Quand ? |
Le 26/09/2023, de 11:00 à 12:00 |
|---|---|
| Où ? | Salle des thèses |
| S'adresser à | Valérie Vidal |
| Participants |
Julien Chauchat |
| Ajouter un événement au calendrier |
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Sediment transport controls the morphological process in rivers, estuaries, and coastal oceans. It is, by nature, a two-phase problem involving fluid-particle and particle-particle interactions covering the full range of particle concentration. At high concentrations, transport is dominated by particle-particle interactions (collisions, enduring contacts), and at lower concentrations, the transport becomes increasingly dominated by turbulent eddies, while those can also be affected in return by the presence of particles. In order to tackle the multiscale nature of particulate flows in geophysics, continuum modeling is a key approach. In this seminar, I will report on the development of a collaborative open-source two-phase flow model, sedFOAM, based on the CFD toolbox OpenFOAM. This model integrates the dense granular flow rheology and the kinetic theory of granular flows for the particle-particle interactions modeling as well as RANS and Large Eddy Simulation (LES) for fluid turbulence modeling. The model has been applied to numerous configurations ranging from fluid bed shear stress-driven transport, the so-called bed-load transport, to gravity-driven flows such as underwater avalanches and granular collapse. These applications illustrate how the continuum modeling can contribute to improving our understanding of sediment transport processes and how it opens new perspectives to address unresolved science questions in this field.