Missions

As it is difficult to model such turbulent flows using simulations, laboratory experiments will be used. For this purpose, the candidate will have access to an experimental room equipped with a 1 m tank, capable of rotating at up to 11 rpm. The aim is to instrument this tank to study topographical effects in the presence of density variation with depth. One of the long-term objectives of this work is to validate the parameterized models currently being studied by the community. This experimental work will be carried out in close collaboration with D. Cébron (PI), M. Solazzo (CNRS engineer, ISTerre) and J. Vidal (CNRS researcher, ENS Lyon). Other interactions are also possible, for example with J. Noir (ETH Zurich) who is working on similar subjects, and with whom we are already interacting.

Activités

The THEIA ERC has funded the construction of a new experimental facility in 2024, which currently houses several experiments designed by a CNRS engineer in-house to study geophysical flows. A 50 cm experiment is already operational, adapted to the study of rapidly rotating regimes, thermal plumes and oscillating flows. To study stratified rotating fluids with minimal effect of centrifugal forces, a larger one-meter tank is being installed on the large THEIA platform.

- PIV (particle image velocimetry) measurements of large-scale flows generated during spin-down, in the presence of small-scale background topography.

- Measurement of drag, and dissipation, in a rapidly rotating fluid, for a sphere and/or topography.

For both studies, we will first use pure water (constant density study), then salt water to study the effect of density variation with depth. Depending on the candidate's interest and motivation, collaboration in ongoing studies on the small experiment could also be envisaged.

Compétences

- Experience in experimental fluid mechanics.
- Team player.
- Knowledge of numerical simulation codes.
- Good level of French.

Contexte de travail

The Centre national de la recherche scientifique is one of the world's leading research institutions. To meet the major challenges of today and tomorrow, its scientists explore life, matter, the Universe and the workings of human society. Internationally recognized for the excellence of its scientific work, the CNRS is a benchmark in the world of research and development, as well as for the general public. The Centre National de la Recherche Scientifique (CNRS) is a public multidisciplinary research organization under the authority of the French Ministry of Higher Education, Research and Innovation.

ISTerre is a joint research unit of Grenoble Alpes University, CNRS, USMB, IRD and Gustave Eiffel University, located at 1381 rue de la Piscine 38400 Saint-Martin d'Hères, on the Bourget du Lac Science Campus. It is part of the Observatoire des Sciences de l'Univers de Grenoble (OSUG) and the PAGE research cluster of the Université Grenoble Alpes (UGA). It employs around 300 people and has an average annual budget of €7 million.
It is organized around 9 research and service teams, with the scientific objective of studying the physics and chemistry of planet Earth, with a particular focus on coupling observations of natural objects with experimentation and modeling of the associated complex processes. ISTerre also carries out solid Earth observation missions, and hosts and maintains national fleets of geophysical instruments, as well as a data center.

The person recruited will join the geodynamo team within the THEIA ERC project.