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.
Equipe Curiosity
site du SP2MI-H2
Bd Marie et Pierre Curie
86360 FUTUROSCOPE CHASSENEUIL
Candidats must be submitted on site of CNRS until the 30/09/2024 : https://emploi.cnrs.fr
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CDD Technicien-ne électronicien-ne - 12 Mois - Catégorie B
POST-DOC (M/F) - Control by Machine Learning of bluff body wakes
At the CNRS-Laboratory PPRIME, based at the Futuroscope, this post-doctorate position is part of the French ANR COWAVE program between the laboratories PRISME in Orleans, Pprime in Poitiers, LHEEA in Nantes and the PSA automotive industry. This Post-Doc position concerns the Pprime contribution to the COWAVE project which aims the experimental exploration of closed-loop wake control strategies with mobile flaps in a water tunnel facility. Three-dimensional bluff-body wakes generate pressure drag and side forces and thus contribute significantly to the fuel consumption and pollutant emission of road vehicles. Despite this crucial impact and the numerous attempts to reduce harmful environmental effect of bluff body wakes by flow control it is still unclear what is the most efficient control strategy! In this context, the ANR project COWAVE addresses two fundamental aspects of wake control: - First, what kind of actuators are most efficient? While most closed-loop control strategies use viscous entrainment effects to actuate the shear layers in the wake, the exploitation of pressure forces produced by mobile deflectors could be an interesting alternative to be tested. - Second, for the implementation of closed-loop control, we want to test if control strategies obtained by machine learning techniques allow to obtain better efficiency and robustness than the more classical model-based approaches? The proposed Post-Doc position is part of the French ANR COWAVE program between the laboratories PRISME in Orleans, Pprime in Poitiers, LHEEA in Nantes and the PSA automotive industry. This Post-Doc position concerns the Pprime contribution to the COWAVE project which aims the experimental exploration of closed-loop wake control strategies with mobile flaps in a water tunnel facility. APPLY Follow link / Application Deadline : 12 March 2021 https://bit.ly/3qDG6Ml