Awardees

• Topic supervised by Christophe ALMARCHA (IRPHE) & Pierre BOIVIN (M2P2)

The scientific consensus on the necessity to reduce the greenhouse gases, like carbon dioxide (CO2),tends to ban the use of carbon-based fossil energy. This leads to intense research on alternative sources of energy. One of the most promising is hydrogen, but it rises questions in terms of safety and control that need to be clarified in order to use it in domestic, transportation and industrial processes (...)fluids The scientific consensus on the necessity to reduce the greenhouse gases, like carbon dioxide (CO2),tends to ban the use of carbon-based fossil energy. This leads to intense research on alternative sources of energy. One of the most promising is hydrogen, but it rises questions in terms of safety and control that need to be clarified in order to use it in domestic, transportation and industrial processes (...)

• Topic supervised by Patrice LE GAL (IRPHE), Benjamin FAVIER (IRPHE), Stephane VIAZZO (M2P2) & Uwe HARLANDER (BTU)

In the various examples mentioned above, which are particularly relevant to understanding the transition to turbulence in stratified geophysical flows, instabilities arise through the resonance of internal waves propagating in the sheared fluid [2,3,4]. In the case of Poiseuille flow, it is the Tollmien-Schlichting waves interacting with gravity waves that give rise to the instability. For strato-rotational instability, it's an interaction of gravito-inertial waves trapped at the walls, while baroclinic instability can be interpreted as the resonance of Rossby waves propagating on vertically separated layers (...)

• Topic supervised by Lounès TADRIST (IUSTI), Irina MARTIN (IUSTI) & Maxime CHINAUD (IUSTI)

Energy conversion systems and faculties generally involve heat. To ensure proper operation of these systems, the heat generated must be controlled by creating appropriate fluidic architectures. Numerous techniques have been implemented to ensure heat transfer at the interface between a wall and a fluid (...)

• Topic supervised by Gautier VERHILE (IRPHE) & Fabien CANDELIER (IUSTI)

Particle clustering is a key parameter to model aggregation in turbulent flows. For heavy spherical particles, it has been shown that this phenomenon is mainly due to centrifugal forces which expel particles form high vortical regions. For thin flexible particles, the situation seems more complex. Their deformability allows the particle to wrap around the vortex core to follow the streamline. This shape is related to a difference of pressure from each side of the particles, the pressure being higher farther from the vortex core. This pressure difference is responsible of a net force that pushes the particle toward the vortex core. The balance of this net force and the centrifugal force might be at the origin of a new equilibrium distance from the vortex core (...)

Thrombus is a biological material that can be considered as a multilayered, porous and inhomogeneous structure showing permeability gradients. Its role in the unfavorable or favorable evolution of vascular pathology has long been a matter of controversy. Its mechanical characteristics, and the hemodynamic mechanisms involved in its formation and evolution are all parameters that may play a part in the role of the thrombus as a predictive marker of the evolution of pathologies. Its characterization is essential to better understand its role/influence and to propose ad hoc models in in silico simulations.

Semi-anechoic rooms are used by manufacturers for the acoustic characterization of products. The objective of the DADA project is to prove that it is possible to realize a semi-anechoic room with an active technology. The idea is to create a full-scale functional demonstrator whose active system developed would make it possible to erase the acoustic effect of 5 walls (not the floor). This project will make it possible to create the first room with active anechoicity.

Non-linear dynamics is at the heart of sound production in a wide variety of musical instruments. Wind instruments (flutes, brasses, woodwinds) relying on self-sustained oscillations are heavily studied at LMA with existing experimental supports. Here, we here aim at developing teaching material to highlight the non-linear behavior of structures when vibrations amplitude become large. Such structures in a musical context correspond percussion instruments such as cymbals or gongs. More precsely, focus is put on the various sounds produced by large gongs, which have proved to display a wide range of behaviours, from linear modal regime to pitch glides or even chaos and wave turbulence.

This project associates the complementary expertise of LMA (aero-acoustics, low frequency noise reduction), IRPHE (flow modelling and characterization) and CSIC (micro-perforated metamaterials) to investigate aero-acoustic solutions for aeronautics and wind turbine sectors: the development of slow sound metamaterials with acoustically neutral interfaces in order to achieve both flow-induced noise attenuation and low drag performance under sheared industrial flows.

The aim of thid project is to determine the rheological properties of real mucus. Using a new transportable rheometer working on sample volumes as low as 70ul, we propose an exhaustive experimental characterization and a modelling of real mucus rheology in the context of improving the clearance process of patients, either suffering from chronical pathologies (severa Asthma, COPD or Cystic Fibrosis) or acute ones (such as COVID-19) that can lead to Severe Acute Respiratory Syndrom.

The aim of this project is to initiate collaborations in the framework of stochastic modelling for fluid dynamics. Taking into account uncertainties in physical phenomenon modelling is of major importance. There exist several methods dealing with data which take into account different sources of uncertainty. In this project, the main purpose is to use stochastic processes having the physical deterministic fluid dynamic model as average and taking into account expert knowledge. The project is in the crossroad of fluid mechanics, applied mathematics and data science.