Annonces

We are pleased to announce our two-week fall school "Bridges over turbulent matters: Navigating across observations, concepts and models", to be held in Cargèse (Corse, France) from October 21 to 31, 2025.To apply, please visit the school website: https://turbazur.github.io/cargese2025/

Colloque en hommage à Laurent Jacquin, organisé du 10 au 12 septembre 2025 au pôle de mécanique de l'école polytechnique à Palaiseau.

Multiphase flows are common in nature and engineering. Atmospheric flows often involve the dispersion of droplets or solid particulate matter (dust, sand, ice crystals in clouds); marine systems are populated by plankton, sediments or microplastics. Industrial applications of disperse flows include particle separators,filtration systems, atomisers and combustion devices, spray dryers, bubble columns; interfacial and free-surface flows are widespread in chemical and process industry.

Going back to Kolmogorov, there has been the paradigm in the more fundamental turbulence community of one universal state of homogeneous isotropic turbulence. In the last 15 years or so it has become more and more clear that this is not the case and that there can be several different states of turbulence, with transitions between these states. The transitions between the different states normally are of subcritical nature, just as the transition from laminar pipe or channel flow to turbulent pipe of channel flow. There, the origin of the subcritical nature is the nonnormality of the operator, combined with the nonlinearity of the Navier-Stokes equation. The nonnormality is intimately related to the local shear of the flow. All this also holds for turbulent flow, where one locally also has strong shear.

Création de la Division Physique Non Linéaire (DPNL) de la Société Française de Physique (SFP)

Cet ouvrage présente les bases de la turbulence aux chercheurs en écologie marine, et les couplages de l’écologie marine avec la turbulence, aux chercheurs en turbulence provenant d’autres disciplines. Il s’adresse aux doctorants, jeunes chercheurs et chercheurs confirmés intéressés par ces deux sujets et leurs interactions.

The Leeds Institute for Fluid Dynamics is delighted to partner with the Department of Applied Mathematics and Theoretical Physics at the University of Cambridge, the UK Fluids Network, and the Journal of Fluid Mechanics to deliver a regular webinar series on fluids-related topics.

An experimental project about the generation and characterisation of an atmospheric boundary layer aiming to study the stability of drones within it.

Fully funded by the French ANR Young Researcher project called SONATE, the aim of the thesis is to understand the aerodynamics, performance and losses of a wind farm at different scales and under inlet flows that correspond to realistic conditions of a real wind farm. The PhD student will carry out large-scale experiments in the atmospheric section of the PRISME wind tunnel, using various measurement tools (pressure, hot-wire, PIV). From these measurements, the project will focus on building representative physics-based reduced-order models, capable of predicting the performance of the wind farms with different inputs depending on the flow conditions (yaw, turbulence, angular momentum added by the blades, etc.).Supervisors: Dr. Cédric Raibaudo (advisor, grant recipient), Pr. Nicolas Mazellier (thesis director)

The present PhD project focuses on experimentally investigating the role of incomingturbulence on an isolated bluff body. The study will be conducted in the IMFT wind tunnelto allow for a wide range of Reynolds numbers, and an active turbulence grid mounted at thetest section inlet will generate the various turbulent inflows (1%characterization downstream different turbulence grid configurations, similar to [8], will enableto determine scenarios of interest, including homogeneous, heterogeneous and unsteady (e.g.gusts) inflows. The effect of these various inflow conditions on a rigidly-mounted bluff bodycan subsequently be investigated, in terms of resulting aerodynamic forces and velocitymeasurements in the wake. By introducing a single degree of freedom to the bluff body’smotion, fluid-structure interactions, such as vortex induced vibrations, can then be studiedthrough the bluff body’s displacement, and velocity measurements in the wake.

The Laboratory of Fluid Mechanics and Acoustics (LMFA) is seeking a highly qualified postdoctoral researcher to contribute to the development of dynamic calibration and optimization strategies for subgrid-scale turbulence modeling within the framework of LB simulations of engineering flows.

Fluid-structure interactions (FSI) in a nuclear reactor core involve thermalhydraulics mechanisms at different scales. FSI simulations at the local (CFD) scale are feasible only for reduced domains. Such domains must however be representative of the actual core conditions. A multi-scale approach is therefore required to understand how to consistently simulate the core thermalhydraulics and the related FSI phenomena.

En tentant de tirer profit du coût mesuré des approches RANS et des qualités prédictives des approches LES, les approches hybrides RANS/LES présentent un intérêt fort pour de nombreuses applications mais continuent à se heurter au problème de la gestion des zones de transition. En l’absence d’instabilité hydrodynamique naturellement présente dans le domaine de calcul ou lorsque celle-ci n’est pas suffisamment résolue, la qualité des prévisions LES dépend ainsi en grande partie des fluctuations prescrites dans la zone de transition. L’objectif du post-doctorat proposé en collaboration avec le CEMEF est de développer une méthode d’apprentissage automatique de génération de fluctuations pour les zones de recouvrement RANS/LES. Deux axes ont été identifiés visant à réduire l’étendue des zones grises ; le premier concerne spécifiquement la qualité du signal synthétique généré alors que le deuxième axe s’attache aux paramètres de contrôle d’une méthode de forçage.

This internship focuses on investigating wall-bounded turbulent flows for heat transfer enhancement applications. The project involves numerical simulations and data analysis to understand the fundamental mechanisms of near-wall turbulence and their impact on heat transfer efficiency.

The postdoctoral fellow will contribute to the development of a stochastic, data-driven model capable of generating high-resolution 3D+1 wind velocity fields. The research will focus on coupling coarse-grid mechanistic simulations with high-frequency local data assimilation using ensemble Kalman filtering techniques. A key challenge will be to reproduce the intermittent, multifractal nature of turbulent flows, crucial for accurate dispersion models in agroecology.

The exchange of viscous fluids induced by a Rayleigh-Taylor instability (RTI) in a confined environment is encountered in a variety of geophysical and industrial problems. For instance, this type of flow is suspected to control the distribution of magma and gas (SO2) released in some types of volcanic eruptions (Stevenson & Blake 1998). Similarly, these exchange flows modify the pressure drop in secondary or enhanced hydrocarbon recovery processes (Joseph et al. 1997).

The wind turbine production in a floating wind farm depends essentially on its position, the wind and the state of the sea. The influence of the state of the sea, in particular, is poorly known, because it has not been an influential factor in the development of installed wind farms. First of all, the influence of the movement of the platform directly affects the production capacity of the wind turbine. But beyond that, it induces significant modifications to the wake, and in the context of commercial farms, where the turbines are not widely spaced, leads to interactions between turbines which are still unknown. As Numerical simulations are very expensive, from numerical simulation and historical data, the environmental conditions can be modeled by stochastic models which are faster to simulate. hus, by combining these stochastic models with the physical model, it is possible to evaluate the uncertainty relating to the key parameters (extractable energy, wake topology).

https://rejoindre.onera.fr/detail-poste?nPostingId=1327&nPostingTargetId=5036&id=P6VFK026203F3VBQB68LOF6Z3&LG=FR⟨uageSelect=FR

The French National Centre for Scientific Research (CNRS) invites outstanding early-career researchers of any nationality to apply for a Junior Professor Chair (Chaire de Professeur Junior) in the field of Fluid Mechanics for Environmental Transitions. This prestigious tenure-track position is part of CNRS’s strategic commitment to addressing critical environmental and societal challenges through cutting-edge research.