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   Home > Directory > C. Morize

Cyprien Morize

Assistant Professor P11

Laboratoire FAST - Bat. 502
Campus Universitaire - 91405 Orsay Cedex  (France)
Phone: 33 1 69 1 53727
Room: 209


Research: Erosion and Resuspension of Granular Bed, Convection

  • Destabilization of an immersed granular bed by thermal convection, in collaboration with E. Herbert (LIED) and A. Sauret (SVI).

  • The transport, dispersion and resuspension of particles occur in industrial fluid dynamical processes as well as environmental and geophysical situations. Whereas the resuspension of an immersed granular bed by fluid flows such as vortices or shear flows has been the focus of many studies, the ability to fluidize particles with a vertical gradient of temperature remains poorly understood. Using laboratory experiments with a localized heat source, we observe that a massive entrainment of particles into the fluid volume occurs beyond a threshold temperature. The buoyancy driven fluidized bed then leads to the transport of solid particles through the generation of particle-laden plumes.

  • Propulsion in the vicinity of a granular media, in collaboration with A. Sauret (SVI) and P. Gondret.

  • In various situations, sand and sediments can be carried by wind or water, which could trigger the resuspension of the granular bed. For instance, when a helicopter lands in sandy environments, its blades trigger air recirculation which leads to the resuspension of particles, thus limiting the pilot's visibility. Here, we focus on a unique situation, in which the resuspension of particles is both sought after and well controlled. Indeed, some bottom-dwelling fish, such as the flounders and stingrays, generate a flow capable of resuspending sand to bury themselves and avoid predators. By flapping their fins with oscillating motions, they create vortices and a recirculating flow that lifts the sand particles up and deposits them on top of their backs. A simple model experiment has been developed to study this situation: a rigid or flexible foil is placed above the sand bed to mimic the fin motion.

  • Erosion in the vicinity of structures, in collaboration with F. Lachaussée (PHD student), Y. Bertho, A. Sauret (SVI) and P. Gondret.

  • Erosion and transport of earth material is a leading threat for human activity and ecosystems. For instance, at the pier of a bridge, erosion can damage the entire structure leading to bridge failure. Achieving better hazard assessment requires coupling both the fluid dynamics around the structure (instabilities, wall effects) and the transport phenomena of solid materials. In this project, we propose to characterize the dynamics of entrainment of particles in the presence of flow in the vicinity of solid submerged structures (bridge piers, offshore structures, ...) using experimental approaches and mathematical models.

  • Tsunami generated by granular collapse, in collaboration with A. Sauret (SVI), A. Hildenbrand (LGMT), Y. Bertho and P. Gondret.

  • A tsunami is a wave that can propagate over long distances and can lead to considerable damage along the coast. These situations showed the necessity to predict or at least to evaluate the risk associated with such extreme events. In particular, whereas the most common trigger for a tsunami is a submarine earthquake, other geological events can be involved. For instance, landslides or cliffs collapse result in tsunamis that lead to important local hazards and need to be understood and predicted. The experimental set-up will be developed to model this situation in 2D by generating a granular collapse into a layer of fluid. The influence of the size and shape of the collapse, the water depth as well as other relevant physical parameters (density of the granular material, sphericity, ...) will be experimentally investigated and modeled.

Past research: Turbulence, Rotating fluids


Citations (google scholar)

Last modification: September 21 2015, 17:43:52.