Download or read book Contribution la validation des m thodes num riques pour les probl mes dynamiques coupl s fluide structure written by Grégory Haboussa and published by . This book was released on 2008 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ce travail vise à améliorer la capacité de prédiction des comportements dynamiques transitoires des solides et des structures lors de sollicitations de type crash, spécifiquement lorsqu’un milieu fluide doit être pris en compte. La première étape a consisté à mesurer une observable expérimentale, caractéristique de l’impact hydrodynamique : l’évolution du chargement en pression sur la paroi de la structure. Pour aboutir à cela, une base expérimentale antérieure d’impact de goutte d’eau sur capteur de pression a été exploitée. La pression de paroi est obtenue en déterminant une fonction de transfert soustrayant l’influence dynamique du capteur sur la mesure par étalonnage dynamique au tube à choc, puis en l’appliquant à ces essais. Une observable expérimentale pertinente relative à l’impact d’une goutte d’eau sur une structure plane étant obtenue, un nouveau cas de validation des méthodes numériques est alors défini. Les performances de plusieurs méthodes numériques sont alors évaluées, en s’intéressant aux profils de pression pariétale obtenus. Ces simulations reposent sur différentes formulations et différentes modélisations de l’interface (continue ou non). La méthode naturelle couplage Éléments Finis -Lagrange Euler associée apporte les résultats les plus convaincants. L’emploi de cette méthode naturelle apparaît finalement comme référence numérique en impact hydrodynamique : aucun paramètre autre que physique n’étant introduit dans le code. En conclusion, la possibilité est bien offerte aujourd’hui de faire avec l’ALE, sous réserve d’un emploi pertinent, des campagnes d’expérience numérique en calcul de structure avec impacts hydrodynamiques

Download or read book Contribution au d veloppement d algorithmes de couplage en interaction fluide structure written by Mustapha Benaouicha and published by . This book was released on 2007 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ce mémoire est une contribution aux études de problèmes d'Interaction Fluide-Structure (IFS). Le code Castem est utilisé afin de créer un outil numérique libre et accessible pour traiter, dans sa globalité, le problème de modélisation d'un barrage ou réservoir souple flottant. Dans un premier temps, nous avons effectué la validation de Castem en absence de couplage fluide-structure. Nous avons considéré une discrétisation spatiale en éléments finis des équations de Navier-Stokes adimensionnelles, le schéma d'Euler implicite pour la discrétisation en temps et la méthode de projection pour le couplage vitesse-pression. La validation s'est portée sur des cas d'écoulement laminaire autour d'un cylindre de section circulaire et carrée. Les résultats obtenus (nombre de Strouhal, coefficients de traînée et de portance, ...) sont très proches des résultats expérimentaux ou issus d'autres calculs numériques réalisés avec d'autres codes de calcul. Ensuite, nous avons procédé à la mise en œuvre des algorithmes de couplage Fluide-Structure sur plusieurs configurations, en laissant les mêmes caractéristiques des schémas de discrétisation des équations du fluide que précédemment. Dans ce cas, on utilise la formulation ALE pour les équations du fluide. Nous avons étudié les oscillations, forcées et libres, d'un cylindre dans un domaine fluide annulaire, en considérant les cas d'un fluide parfait puis d'un fluide visqueux. Dans le cas des oscillations forcées où le mouvement harmonique du cylindre est imposé, les résultats obtenus (coefficient de masse ajoutée, efforts fluides sur le cylindre, ...) comparés aux résultas données par les modèles de Fritz, dans le cas d'un fluide non visqueux, et Sinyavaski ou Chen, dans le cas d'un fluide visqueux, sont assez précis. Dans le cas des oscillations libres où le mouvement du cylindre est déterminé par l'action couplée fluide-solide, nous avons constaté que l'algorithme de couplage implicite est celui qui prédit le mieux les oscillations de la structure. Nous étions néanmoins contraint d'introduire des sous-pas de temps pour le solide afin d'obtenir de meilleurs résultats. Le code développé dans Castem, a été aussi testé avec succès pour prédire les phénomènes liés au cas d'un cylindre en oscillations dans un écoulement laminaire incompressible (accrochage fréquentiel, modes d'émission de tourbillons, ...).Pour l'application, une configuration proche de l'objectif initial de la thèse, qui est la modélisation des barrages flottants et réservoirs souples, a été traitée. L'objet de cette application est l'étude du déplacement d'un anneau complètement immergé dans un fluide en écoulement laminaire et amarré par un câble à la paroi inférieure du domaine fluide. Enfin, une introduction à une méthode de réduction de modèle en Interaction Fluide-Structure, la POD, est présentée. Il s'agit d'une méthode déjà utilisée en mécanique des fluides et en mécanique des structures mais en stade de développement en IFS. Elle a été appliquée à certaines configurations étudiées précédemment et les résultats obtenus sont prometteurs.

Download or read book Port Hamiltonian Systems Theory written by Schaft Van Der and published by . This book was released on 2014-06-13 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: Port-Hamiltonian Systems Theory: An Introductory Overview provides a concise and easily accessible description of the foundations underpinning the subject and emphasizes novel developments in the field, which will be of interest to a broad range of researchers.

Download or read book The General Theory of Homogenization written by Luc Tartar and published by Springer Science & Business Media. This book was released on 2009-12-03 with total page 466 pages. Available in PDF, EPUB and Kindle. Book excerpt: Homogenization is not about periodicity, or Gamma-convergence, but about understanding which effective equations to use at macroscopic level, knowing which partial differential equations govern mesoscopic levels, without using probabilities (which destroy physical reality); instead, one uses various topologies of weak type, the G-convergence of Sergio Spagnolo, the H-convergence of François Murat and the author, and some responsible for the appearance of nonlocal effects, which many theories in continuum mechanics or physics guessed wrongly. For a better understanding of 20th century science, new mathematical tools must be introduced, like the author’s H-measures, variants by Patrick Gérard, and others yet to be discovered.

Download or read book Active Subspaces written by Paul G. Constantine and published by SIAM. This book was released on 2015-03-17 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt: Scientists and engineers use computer simulations to study relationships between a model's input parameters and its outputs. However, thorough parameter studies are challenging, if not impossible, when the simulation is expensive and the model has several inputs. To enable studies in these instances, the engineer may attempt to reduce the dimension of the model's input parameter space. Active subspaces are an emerging set of dimension reduction tools that identify important directions in the parameter space. This book describes techniques for discovering a model's active subspace and proposes methods for exploiting the reduced dimension to enable otherwise infeasible parameter studies. Readers will find new ideas for dimension reduction, easy-to-implement algorithms, and several examples of active subspaces in action.

Download or read book Design and Modeling of Mechanical Systems written by Mohamed Haddar and published by Springer Science & Business Media. This book was released on 2013-03-12 with total page 653 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 5th International Congress on Design and Modeling of Mechanical Systems (CMSM) was held in Djerba, Tunisia on March 25-27, 2013 and followed four previous successful editions, which brought together international experts in the fields of design and modeling of mechanical systems, thus contributing to the exchange of information and skills and leading to a considerable progress in research among the participating teams. The fifth edition of the congress (CMSM ́2013), organized by the Unit of Mechanics, Modeling and Manufacturing (U2MP) of the National School of Engineers of Sfax, Tunisia, the Mechanical Engineering Laboratory (MBL) of the National School of Engineers of Monastir, Tunisia and the Mechanics Laboratory of Sousse (LMS) of the National School of Engineers of Sousse, Tunisia, saw a significant increase of the international participation. This edition brought together nearly 300 attendees who exposed their work on the following topics: mechatronics and robotics, dynamics of mechanical systems, fluid structure interaction and vibroacoustics, modeling and analysis of materials and structures, design and manufacturing of mechanical systems. This book is the proceedings of CMSM ́2013 and contains a careful selection of high quality contributions, which were exposed during various sessions of the congress. The original articles presented here provide an overview of recent research advancements accomplished in the field mechanical engineering.

Download or read book Recent Advances in Integrated Design and Manufacturing in Mechanical Engineering written by Grigore Gogu and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 541 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents recent advances in the integration and the optimization of product design and manufacturing systems. The book is divided into 3 chapters corresponding to the following three main topics : - optimization of product design process (mechanical design process, mass customization, modeling the product representation, computer support for engineering design, support systems for tolerancing, simulation and optimization tools for structures and for mechanisms and robots), -optimization of manufacturing systems (multi-criteria optimization and fuzzy volumes, tooth path generation, machine-tools behavior, surface integrity and precision, process simulation), - methodological aspects of integrated design and manufacturing (solid modeling, collaborative tools and knowledge formalization, integrating product and process design and innovation, robust and reliable design, multi-agent approach in VR environment). The present book is of interest to engineers, researchers, academic staff, and postgraduate students interested in integrated design and manufacturing in mechanical engineering.

Download or read book Additive Runge Kutta Schemes for Convection diffusion reaction Equations written by Christopher Alan Kennedy and published by . This book was released on 2001 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: Additive Runge-Kutta (ARK) methods are investigated for application to the spatially discretized one-dimensional convection-diffusion-reaction (CDR) equations. First, accuracy, stability, conservation, and dense output are considered for the general case when N different Runge-Kutta methods are grouped into a single composite method. Then, implicit-explicit, N=2, additive Runge-Kutta ARK methods from third- to fifth-order are presented that allow for integration of stiff terms by an L-stable, stiffly-accurate explicit, singly diagonally implicit Runge-Kutta (ESDIRK) method while the nonstiff terms are integrated with a traditional explicit Runge-Kutta method (ERK). Coupling error terms are of equal order to those of the elemental methods. Derived ARK methods have vanishing stability functions for very large values of the stiff scaled eigenvalue and retain high stability efficiency in the absence of stiffness.

Download or read book Advances in Hydroinformatics written by Philippe Gourbesville and published by Springer. This book was released on 2018-02-26 with total page 1205 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gathers a collection of extended papers based on presentations given during the SimHydro 2017 conference, held in Sophia Antipolis, Nice, France on June 14–16, 2017. It focuses on how to choose the right model in applied hydraulics and considers various aspects, including the modeling and simulation of fast hydraulic transients, 3D modeling, uncertainties and multiphase flows. The book explores both limitations and performance of current models and presents the latest developments in new numerical schemes, high-performance computing, multiphysics and multiscale methods, and better interaction with field or scale model data. It gathers the lastest theoretical and innovative developments in the modeling field and presents some of the most advance applications on various water related topics like uncertainties, flood simulation and complex hydraulic applications. Given its breadth of coverage, it addresses the needs and interests of practitioners, stakeholders, researchers and engineers alike.

Download or read book Dynamique Non lin aire Et Le Chaos written by and published by . This book was released on 1993 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Mastering Calculations in Linear and Nonlinear Mechanics written by Pierre Ladevèze and published by Springer Science & Business Media. This book was released on 2004-12-16 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book deals with the management of calculations in linear and nonlinear mechanics. Particular attention is given to error estimators and indicators for structural analysis. The accent is on the concept of error in constitutive relation. An important part of the work is also devoted to the utilization of the error estimators involved in a calculation, beginning with the parameters related to the mesh. Many of the topics are taken from the most recent research by the authors: local error estimators, extention of the concept of error in constitutive relation to nonlinear evolution problems and dynamic problems, adaptive improvement of calculations in nonlinear mechanics. This work is intended for all those interested in mechanics: students, researchers and engineers concerned with the construction of models as well as their simulation for industrial purposes.

Download or read book New Directions in Mathematical Fluid Mechanics written by Andrei V. Fursikov and published by Springer Science & Business Media. This book was released on 2010-01-11 with total page 435 pages. Available in PDF, EPUB and Kindle. Book excerpt: On November 3, 2005, Alexander Vasil’evich Kazhikhov left this world, untimely and unexpectedly. He was one of the most in?uential mathematicians in the mechanics of ?uids, and will be remembered for his outstanding results that had, and still have, a c- siderablysigni?cantin?uenceinthe?eld.Amonghis manyachievements,werecall that he was the founder of the modern mathematical theory of the Navier-Stokes equations describing one- and two-dimensional motions of a viscous, compressible and heat-conducting gas. A brief account of Professor Kazhikhov’s contributions to science is provided in the following article “Scienti?c portrait of Alexander Vasil’evich Kazhikhov”. This volume is meant to be an expression of high regard to his memory, from most of his friends and his colleagues. In particular, it collects a selection of papers that represent the latest progress in a number of new important directions of Mathematical Physics, mainly of Mathematical Fluid Mechanics. These papers are written by world renowned specialists. Most of them were friends, students or colleagues of Professor Kazhikhov, who either worked with him directly, or met him many times in o?cial scienti?c meetings, where they had the opportunity of discussing problems of common interest.

Download or read book Finite Volumes for Complex Applications IX Methods Theoretical Aspects Examples written by Robert Klöfkorn and published by Springer Nature. This book was released on 2020-06-09 with total page 727 pages. Available in PDF, EPUB and Kindle. Book excerpt: The proceedings of the 9th conference on "Finite Volumes for Complex Applications" (Bergen, June 2020) are structured in two volumes. The first volume collects the focused invited papers, as well as the reviewed contributions from internationally leading researchers in the field of analysis of finite volume and related methods. Topics covered include convergence and stability analysis, as well as investigations of these methods from the point of view of compatibility with physical principles. Altogether, a rather comprehensive overview is given on the state of the art in the field. The properties of the methods considered in the conference give them distinguished advantages for a number of applications. These include fluid dynamics, magnetohydrodynamics, structural analysis, nuclear physics, semiconductor theory, carbon capture utilization and storage, geothermal energy and further topics. The second volume covers reviewed contributions reporting successful applications of finite volume and related methods in these fields. The finite volume method in its various forms is a space discretization technique for partial differential equations based on the fundamental physical principle of conservation. Many finite volume methods preserve further qualitative or asymptotic properties, including maximum principles, dissipativity, monotone decay of free energy, and asymptotic stability, making the finite volume methods compatible discretization methods, which preserve qualitative properties of continuous problems at the discrete level. This structural approach to the discretization of partial differential equations becomes particularly important for multiphysics and multiscale applications. The book is a valuable resource for researchers, PhD and master’s level students in numerical analysis, scientific computing and related fields such as partial differential equations, as well as engineers working in numerical modeling and simulations.

Download or read book A Quest Towards a Mathematical Theory of Living Systems written by Nicola Bellomo and published by Birkhäuser. This book was released on 2017-07-13 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt: This monograph aims to lay the groundwork for the design of a unified mathematical approach to the modeling and analysis of large, complex systems composed of interacting living things. Drawing on twenty years of research in various scientific fields, it explores how mathematical kinetic theory and evolutionary game theory can be used to understand the complex interplay between mathematical sciences and the dynamics of living systems. The authors hope this will contribute to the development of new tools and strategies, if not a new mathematical theory. The first chapter discusses the main features of living systems and outlines a strategy for their modeling. The following chapters then explore some of the methods needed to potentially achieve this in practice. Chapter Two provides a brief introduction to the mathematical kinetic theory of classical particles, with special emphasis on the Boltzmann equation; the Enskog equation, mean field models, and Monte Carlo methods are also briefly covered. Chapter Three uses concepts from evolutionary game theory to derive mathematical structures that are able to capture the complexity features of interactions within living systems. The book then shifts to exploring the relevant applications of these methods that can potentially be used to derive specific, usable models. The modeling of social systems in various contexts is the subject of Chapter Five, and an overview of modeling crowd dynamics is given in Chapter Six, demonstrating how this approach can be used to model the dynamics of multicellular systems. The final chapter considers some additional applications before presenting an overview of open problems. The authors then offer their own speculations on the conceptual paths that may lead to a mathematical theory of living systems hoping to motivate future research activity in the field. A truly unique contribution to the existing literature, A Quest Toward a Mathematical Theory of Living Systems is an important book that will no doubt have a significant influence on the future directions of the field. It will be of interest to mathematical biologists, systems biologists, biophysicists, and other researchers working on understanding the complexities of living systems.

Download or read book ICREEC 2019 written by Ahmed Belasri and published by Springer Nature. This book was released on 2020-06-10 with total page 659 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights peer reviewed articles from the 1st International Conference on Renewable Energy and Energy Conversion, ICREEC 2019, held at Oran in Algeria. It presents recent advances, brings together researchers and professionals in the area and presents a platform to exchange ideas and establish opportunities for a sustainable future. Topics covered in this proceedings, but not limited to, are photovoltaic systems, bioenergy, laser and plasma technology, fluid and flow for energy, software for energy and impact of energy on the environment.

Download or read book Mechanics of Ballasted Rail Tracks written by Buddhima Indraratna and published by CRC Press. This book was released on 2005-08-11 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book, the authors discuss testing of ballast, including the strength, deformation and degradation aspects of fresh and recycled ballast under monotonic and cyclic loading. The effectiveness of geosynthetics in stabilising recycled ballast has also been examined. A new stress-strain constitutive model for ballast incorporating particle breakage is presented. Finally, a new range of particle gradations, balancing the strength and permeability requirements, has been proposed for future rail tracks. This book is intended as a reference text for final year civil engineering students and postgraduates, and for practicing railway engineers with the task of modernizing existing designs.

Download or read book Soil Analysis written by J. Gautheyrou and published by CRC Press. This book was released on 2001-01-01 with total page 514 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this book is to provide a better understanding of tools for soil analysis in order to use them more efficiently. It covers sampling problems as well as difficulties relating to actual analysis and quality control.