A hybrid method for modelling two dimensional non-breaking and breaking waves

This is the first paper to present a hybrid method coupling a Improved Meshless Local Petrov Galerkin method with Rankine source solution (IMLPG_R) based on the Navier Stokes (NS) equations, with a finite element method (FEM) based on the fully nonlinear potential flow theory (FNPT) in order to efficiently simulate the violent waves and their interaction with marine structures. The two models are strongly coupled in space and time domains using a moving overlapping zone, wherein the information from both the solvers is exchanged. In the time domain, the Runge-Kutta 2nd order method is nested with a predictor-corrector scheme. In the space domain, numerical techniques including ‘Feeding Particles’ and two-layer particle interpolation with relaxation coefficients are introduced to achieve the robust coupling of the two models. The properties and behaviours of the new hybrid model are tested by modelling a regular wave, solitary wave and Cnoidal wave including breaking and overtopping. It is validated by comparing the results of the method with analytical solutions, results from other methods and experimental data. The paper demonstrates that the method can produce satisfactory results but uses much less computational time compared with a method based on the full NS model

Modélisation du comportement des gaz de fission en régime transitoire dans le combustible à plaques

CHATENAY MALABRY-Ecole centrale (920192301) / SudocSudocFranceF

Etude métallurgique du comportement en fatigue d'aciers sans interstitiels au voisinage de la température ambiante

CHATENAY MALABRY-Ecole centrale (920192301) / SudocSudocFranceF

Suivi d'interface tridimensionnel (application au déferlement)

L'objet de cette thèse est de mettre en oeuvre puis de valider dans un code de calcul industriel (EOLE de la société Principia R&D) une méthode numérique originale permettant de suivre l'interface entre deux fluides pour un écoulement tridimensionnel : la méthode " Segment-Lagrangian Volume Of Fluid 3D " (SL-VOF 3D). Le document s'articule autour de cinq parties. La première partie décrit les hypothèses de calcul dans lesquelles on se place, et définit le modèle mathématique utilisé. La seconde partie propose une revue des différents types de méthodes de suivi d'interface étudiées et s'efforce de dégager les qualités et les défauts de chacune. La troisième partie définit le modèle numérique utilisé et décrit en détail la méthode de suivi d'interface développée. Cette méthode est de type " Volume Of Fluid " et combine une représentation affine par morceaux de l'interface et une advection lagrangienne. Dans la quatrième partie les performances de la méthode sont évaluées sur différents cas-tests. On compare ensuite les résultats avec des solutions analytiques ou avec des résultats obtenus avec d'autres méthodes. Enfin, dans la cinquième partie, on applique la méthode au déferlement de vagues. Un couplage avec une méthode d'éléments frontières est effectué. Le déferlement plongeant d'ondes solitaires sur des fonds de pentes variables est ainsi simulé et illustre l'intérêt de la méthode proposée.The aim of this thesis is to built and to validate in a CFD code (EOLE of the company Principia R&D) an original numerical method allowing to track the interface between two fluids for 3-D flows: the "Segment Lagrangian Volume Of Fluid 3-D" method (SL-VOF 3-D). The document is divided in five parts. The first part describes the computational hypothesis and the mathematical model used. The second part deals with some numerical interface tracking method studied and explains the advantages and the drawbacks of each one. The third part defines the numerical model used and describes the developed interface tracking method. This method is a Volume Of Fluid type method and combines a piecewise linear representation of the interface and a lagrangian advection. In the fourth part the capacities of the method are evaluated through different test cases. The results are then compared with analytical solutions or with results obtained with others methods. Finally, in the fifth part, the method is applied to wave breaking. A coupling with a boundary elements method is achieved. Plunging breakers on sloping bottoms are simulated. This illustrates the capability of the developed method.TOULON-BU Centrale (830622101) / SudocSudocFranceF

CentraleSupélec. New curriculum. Statement of objectives

Within the context of globalization and the competitive environment among the best institutions in the world, CentraleSupélec's ambition is to become a world-class institution of reference on a global scale for its four core activities: training of top-level generalist engineers, specific professional courses, training to and via research, supported by its Doctoral School, research in Engineering and Systems Sciences.To achieve this goal, it is essential to offer a state-of-the-art engineering curriculum of the highest level. It is the flagship and foundation of the Engineering school, whose first mission is to open successful career paths for its graduates who are at the service of society. This documents is the statement of objectives of the new CentraleSupélec curriculum. It is based on the research and work of the project members: Aldebert, Patrick; Aubin, Véronique; Bourda, Yolaine; Cagnol, John; Dellevedove, Serge; Dumur, Didier; Herbin, Eric; Ferreboeuf, Valérie; Fiorina, Jocelyn; Font, Stéphane; Gillet, Jean-Michel; Richecoeur, Franck; Zeitoun, Alain

Un tissu industriel encore trop centralisé: Le Monde

lemonde.frLa France a besoin d'entreprises plus réactives et innovantes

Oxidation of Silicon Nitride Bonded Silicon Carbide Refractory Material in Air and Carbon Dioxide

International audienc

Numerical Simulations of Three-dimensional Wave Breaking by Coupling of a VOF Method and a Boundary Element Method

In this paper, we describe the development and validation of a numerical model based on coupling a higher-order Boundary Element Method (BEM) solution of fully nonlinear potential flow equations to a Volume Of Fluid (VOF) solution of Euler equations, in three-dimensions (3-D). In the model, the BEM solution is used to initialize the VOF/Euler computations. Numerical simulations of breaking waves on sloping beaches for 2-D (using an earlier model) and 3-D flows are carried out