The study will involve detailed experimental characterisation of an annular hydrogen flame and the sound it generates. The goal will be to understand and modelling the flow/flame dynamics and related sound-generation mechanisms. High-precision, spatiotemporally resolved, optical diagnostics will be used to explore and characterise the flame. Microphone arrays will be used to map the sound field. Synchronisation of the measurement systems will permit causal relationships to be established between the sound, flow and combustion dynamics. Data-reduction techniques will be implemented to identify key mechanisms and to guide the development of simplified models for the combustion and sound-generation processes.
Catégorie d\'emplois: Employment FTC
Catalytic systems for H2O2 decomposition: space propulsion application
Fixed-term contract Post-Doctoral researcher: Experimental and numerical studies of boat-waterways interaction with analogous experiments and in towing tanks
The Curiosity team at the Pprime institute wishes to recruit a post-doctoral student as part of a collaboration with the Voies Navigables de France (VNF) and the Laboratory of Mathematics and Applications (LMA) of Poitiers in order to study the navigation in a confined environment with a view to fluid-structure interaction. In addition to a post-doctoral project in progress on a revisit of theoretical work on the effects of hydraulic and undulatory confinement for a river boat interacting with the structure (typically a trapezoidal canal), we now wish to feed the theoretical studies by experiments to screen the models as well as to guide modelers towards the relevant models due to gaps in the understanding of the phenomena as revealed by the analysis of the literature and which the experiments could fill. The work of the theoretical post-doctoral student in support of the future experimental post-doctorate was first bibliographical on the basis of a state of the art provided by VNF of the scientific theories available in the field of waterways. The consortium thus formed between Pprime, the LMA and VNF has since then worked to extend the theories on navigation in confined environments from the literature by removing simplifications and inaccuracies and, by attempting to unify them in a complete theory integrating practical knowledge as well as as engineering type formulations with work in applied mathematics on the calculations of resistance to the progress of the ship to arrive at an analytical formulation of the whole which can serve as an operational basis.
Therefore, we propose a post-doctoral subject combining experiments of fluid-structure interactions in the channels of the Pprime Institute and theoretical/numerical modeling. On the experimental level, the recruited post-doctoral student will characterize the flow regimes around and above a fixed bottom obstacle which does not occupy the entire width of the channel in a central position then eccentric (the analog boat moves closer to the banks) in relation to a free surface canal 3m long with a canal section of rectangular/trapezoidal/triangular/any geometric shape. Then the obstacle will be turned over and fixed on a vertical actuator: a classification of the flows around the obstacle which is first rigid then allowed to pitch and/or pound will be sought. Finally, a scale-up in the 30 m long hull test tank of the PHE platform of the Pprime Institute (environmental hydrodynamics platform: https://pprime.fr/la-recherche/fluides-thermique-combustion/plateforme-hydrodynamique-environnementale-fr/?cn-reloaded=1 ) will be carried out to complicate the situation compared to the model case of the obstacle in a flow (Figure 2). Background obstacles designed by 3D printing with different geometries (continuous and discontinuous, see Figure 2) and aspect ratios will be studied. Model boats with different block coefficients will be used.
PhD Thesis position – Hydrogen combustion applied to aeronautical propulsion: experimental characterization and analysis of flame-wall interactions
MODIFIED ISPH METHOD FOR MODELING THE WAVES INTERACTION WITH THE COASTAL PROTECTION STRUCTURES
Job FTC: Associate Professor Position – ISAE-ENSMA – Analysis and modelling of high-Reynolds-number, turbulent aerodynamics.
Teaching : Aerodynamics and Fluid Mechanics
Le candidat assurera ses enseignements en français et en anglais au sein du Département Mécanique des Fluides-Aérodynamique de l’ENSMA (9 enseignants-chercheurs). Il devra fortement s’impliquer dans les cours, travaux pratiques, travaux dirigés et projets dispensés dans ce département. Il interviendra plus particulièrement dans les thématiques suivantes :
• Aérodynamique compressible et incompressible
• Mécanique des fluides
• Méthodes numériques, modélisation et simulation CFD d’écoulements turbulents
Le candidat sera d’autre part associé activement à la définition et à la mise en œuvre des objectifs pédagogiques du département et de l’établissement, et l’accompagnement et le suivi de projets d’étudiants.
Research : The research will take place in the team Acoustics, Aerodynamics and Turbulence (2AT) of the PPRIME Institute.
Profile of the candidate : The candidate should be an experienced researcher in the domain of computational fluid mechanics with a strong interest in aerodynamics and turbulence. He/she should
have experience in the development of reduced-order models for prediction, estimation and control. Scientific approach: The physical modelling of flows involving turbulent aerodynamics at high
Reynolds number is a key research activity at the Pprime Institute, and in particular with respect to the impact of these flows on observables such as drag, lift, structural vibration, vehicle stability, acoustic emissions,… With the rapid progression of experimental diagnostics and high-fidelity simulation, we have unprecedented access to the spatiotemporal organisation of these flows. To be useful for understanding, design, estimation or control, such data requires reduction and representation using reduced-order models, which may be linear, non-linear, model-based or data-driven. The candidate should have experience in the domains of computational fluid mechanics, and will be expected to bring his/her skills to the team so as to develop reduced-order modelling strategies adapted to turbulent, threedimensional flows involving complex geometries. These developments will be central in enhancing the synergy between experiments, computations and modelling. The candidate will be open to industrial or academic collaborations at a national or international level.