Download or read book tude de contraintes et qualification de mod les aux tensions de Reynolds written by Laurent Flachard and published by . This book was released on 2000 with total page 321 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cette étude traite des prévisions des modèles de turbulence transportant directement le tenseur de Reynolds. Ces modèles sont appelés Reynolds Stress Model (RSM). Après avoir rappelé les bases de la modélisation RSM, les modèles sont étudiés dans des écoulements d'une complexité croissante. Ce mémoire commence ainsi par l'étude des modèles RSM en turbulence homogène, aborde ensuite les écoulements inhomogènes et s'achève par le cas de la couche limite soumise à un gradient de pression positif. En écoulement homogène et inhomogène, diverses configurations sont prises en compte. Les modèles sont qualifiés aussi bien analytiquement que numériquement. Le cas de la couche limite soumise à un gradient de pression positif présente un réel intérêt industriel en permettant de simuler le comportement de la couche limite avant son décollement. Certaines propriétés des couches limites sont d'abord identifiées. Par des analyses théoriques, chacune de ces propriétés est traduite en contrainte mathématique que la modélisation devra respecter. La pertinence de chaque théorie est ensuite démontrée numériquement. Ceci nous permet de qualifier les modèles sélectionnés. Une méthode d'obtention de modèle RSM vérifiant tous les comportements physiques est alors mise en place. Elle débouche sur un modèle simple donnant de bons résultats sur la diversité des écoulements étudiés.
Download or read book Engineering Turbulence Modelling and Experiments 6 written by Wolfgang Rodi and published by Elsevier. This book was released on 2005-05-05 with total page 1011 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of the world renowned ERCOFTAC (International Symposium on Engineering Turbulence Modelling and Measurements).The proceedings include papers dealing with the following areas of turbulence:·Eddy-viscosity and second-order RANS models ·Direct and large-eddy simulations and deductions for conventional modelling ·Measurement and visualization techniques, experimental studies ·Turbulence control ·Transition and effects of curvature, rotation and buoyancy on turbulence ·Aero-acoustics ·Heat and mass transfer and chemically reacting flows ·Compressible flows, shock phenomena ·Two-phase flows ·Applications in aerospace engineering, turbomachinery and reciprocating engines, industrial aerodynamics and wind engineering, and selected chemical engineering problems Turbulence remains one of the key issues in tackling engineering flow problems. These problems are solved more and more by CFD analysis, the reliability of which depends strongly on the performance of the turbulence models employed. Successful simulation of turbulence requires the understanding of the complex physical phenomena involved and suitable models for describing the turbulent momentum, heat and mass transfer. For the understanding of turbulence phenomena, experiments are indispensable, but they are equally important for providing data for the development and testing of turbulence models and hence for CFD software validation. As in other fields of Science, in the rapidly developing discipline of turbulence, swift progress can be achieved only by keeping up to date with recent advances all over the world and by exchanging ideas with colleagues active in related fields.
Download or read book tude de contraintes et qualification de mod les viscosit turbulente written by Stéphane Catris and published by . This book was released on 1999 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cette étude traite des prévisions des modèles de turbulence. Nous nous sommes principalement centrés sur les modèles à viscosité turbulente ou viscosité tourbillonnaire avec équations de transport. La configuration d'écoulement est la couche limite turbulente pour laquelle les moyens de calcul ne permettent pas de résoudre complètement le système d'équations du mouvement instantanné. Deux effets agissant sur ce type d'écoulements sont étudiés indépendamment l'un de l'autre pour ne pas mêler les effets. Nous nous intéressons tout d'abord à l'effet de la compressibilité de l'écoulement dans une couche limite supersonique. Le second paramètre pris en compte est le gradient de pression pour la couche limite incompressible. Les applications de ce travail concernent le domaine aéronautique et les problèmes d'aérodynamique. En premier lieu, certaines propriétés des couches limites sont identifiées. Chacune de ces contraintes physiques est traduite en contrainte mathématique pour le modèle par l'intermédiaire d'une théorie. La pertinence de chaque théorie est ensuite démontrée numériquement. La démarche théorique ainsi que le calcul numérique permettent de qualifier les modèles sélectionnés. Pour la couche limite compressible, une nouvelle écriture de modèle est considérée qui permet de prendre en compte l'effet de compressibilité. Son bon comportement théorique et numérique est alors prouvé. Pour la couche limite soumise à un gradient de pression, un modèle exploratoire est développé permettant de reproduire un maximum de contraintes physiques. Son bon comportement est également démontré.
Download or read book Mod les aux tensions de Reynolds avec prise en compte de l intermittence de fronti re written by Paul Ferrey and published by . This book was released on 2004 with total page 215 pages. Available in PDF, EPUB and Kindle. Book excerpt: Le but de cette thèse est d’optimiser un modèle aux tensions de Reynolds. Des contraintes lui sont appliquées pour reproduire l’influence d’un gradient de pression sur la structure de la couche limite. Ceci a conduit à revoir le comportement des modèles de turbulence au voisinage d'une frontière libre. On obtient un comportement différent de celui classiquement supposé : la solution en puissance attendue est incluse dans une solution plus complexe. Les contraintes pour la frontière libre sont alors incompatibles avec les autres contraintes. Le caractère intermittent de la frontière libre a dû être pris en compte afin de découpler le comportement du modèle au voisinage d’une frontière libre de son comportement dans une région pleinement turbulente, ceci dans le but de satisfaire toutes les contraintes. Le modèle construit est optimisé sur les écoulements libres et la couche limite pour laquelle les contraintes imposées apportent une amélioration sensible.
Download or read book Etude math matique des mod les aux tensions de Reynolds et simulation num rique d coulements turbulents sur parois fixes et mobiles written by Gorazd Medic and published by . This book was released on 1999 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mod lisation des tensions de Reynolds written by Nicolas Devaux and published by . This book was released on 1996 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt: LE BUT DE CETTE THESE EST DE SIMULER A L'AIDE D'UN CODE DE CALCUL LES ECOULEMENTS TRIDIMENSIONNELS, INCOMPRESSIBLES ET TURBULENTS AUTOUR DE VEHICULES AUTOMOBILES. LA TECHNIQUE UTILISEE EST CELLE DES ELEMENTS FINIS. NOUS TRAITONS LA TURBULENCE PAR UNE APPROCHE STATISTIQUE CLASSIQUE EN RESOLVANT LES EQUATIONS COMPLETES DE NAVIER-STOKES MOYENNEES. NOUS NOUS SOMMES INTERESSES AU MODELE A UNE EQUATION DE WOLFSTEIN, UTILISABLE JUSQU'AUX PAROIS SOLIDES. ENSUITE, NOUS NOUS SOMMES INTERESSES AU MODELE K-EPSILON AVEC UNE LOI DE PAROI. ENFIN, NOUS AVONS ETUDIE ASSEZ PRECISEMENT UN MODELE ASSEZ FREQUEMMENT UTILISE, DIT MODELE ALGEBRIQUE DES TENSIONS DE REYNOLDS. CELUI-CI EST ANALOGUE AUX MODELES DIFFERENTIELS DES TENSIONS DE REYNOLDS MAIS LES EQUATIONS DIFFERENTIELLES SONT REMPLACEES PAR DES EQUATIONS ALGEBRIQUES. NOTRE ETUDE MONTRE QUE LE MODELE ALGEBRIQUE DES TENSIONS DE REYNOLDS DONNE UNE SOLUTION UNIQUE DANS UN ENSEMBLE FACILEMENT IDENTIFIABLE (PROCHE D'UNE TURBULENCE ISOTROPE) POUR DES ECOULEMENTS AVEC DE FAIBLES GRADIENTS DE VITESSE MAIS QU'EN GENERAL PLUSIEURS SOLUTIONS EXISTENT POUR UN GRADIENT DE VITESSE QUELCONQUE. APRES APPLICATION A DIVERS CAS-TESTS, LES DIFFERENTS MODELES ONT ETE UTILISES POUR CALCULER L'ECOULEMENT AUTOUR D'UN VEHICULE AUTOMOBILE
Download or read book Charges Et Les Sp cifications Des Avions Militaires written by North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development. Structures and Materials Panel. Meeting and published by . This book was released on 1997 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Extraterrestrial Seismology written by Vincent C. H. Tong and published by Cambridge University Press. This book was released on 2015-06-25 with total page 467 pages. Available in PDF, EPUB and Kindle. Book excerpt: Taking a transdisciplinary approach to seismology, this unique book reviews the most recent developments in planetary seismology, helioseismology, and asteroseismology.
Download or read book Free and Fair Elections written by Guy S. Goodwin-Gill and published by Inter-Parliamentary Union. This book was released on 2006 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book ROUTLEDGE ENCYCLOPEDIA OF INTERPRETING STUDIES written by Franz Pochhacker and published by Routledge. This book was released on 2015-09-25 with total page 1269 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Routledge Encyclopedia of Interpreting Studies is the authoritative reference for anyone with an academic or professional interest in interpreting. Drawing on the expertise of an international team of specialist contributors, this single-volume reference presents the state of the art in interpreting studies in a much more fine-grained matrix of entries than has ever been seen before. For the first time all key issues and concepts in interpreting studies are brought together and covered systematically and in a structured and accessible format. With all entries alphabetically arranged, extensively cross-referenced and including suggestions for further reading, this text combines clarity with scholarly accuracy and depth, defining and discussing key terms in context to ensure maximum understanding and ease of use. Practical and unique, this Encyclopedia of Interpreting Studies presents a genuinely comprehensive overview of the fast growing and increasingly diverse field of interpreting studies.
Download or read book The Ecology of Even aged Forest Plantations written by International Union of Forestry Research Organizations. Division I--Site and Silviculture and published by . This book was released on 1979 with total page 604 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The J Paul Getty Museum Journal written by The J. Paul Getty Museum and published by Getty Publications. This book was released on 1985-01-01 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: The J. Paul Getty Museum Journal 13 is a compendium of articles and notes pertaining to the Museum's permanent collections of antiquities, decorative arts, drawings, paintings, and photographs. This volume includes a supplement introduced by John Walsh with a fully illustrated checklist of the Getty’s recent acquisitions. Volume 13 includes articles written by Helayna I. Thickpenny, Michael Pfrommer, Klaus Parlasca, Heidemaire Koch, Jean-Dominique Augarde, Colin Streeter, Gillian Wilson, Charissa Bremer-David, C. Gay Nieda, Adrian Sassoon, Selma Holo, Marcel Roethlisberger, Louise Lippincott, Mark Leonard, Burton B. Fredericksen, Nigel Glendinning, Eleanor Sayre, and William Innes Homer.
Download or read book Computational Methods for Fluid Dynamics written by Joel H Ferziger and published by . This book was released on 1996-02-14 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Buyology written by Martin Lindstrom and published by Currency. This book was released on 2010-02-02 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: NEW YORK TIMES BESTSELLER • “A fascinating look at how consumers perceive logos, ads, commercials, brands, and products.”—Time How much do we know about why we buy? What truly influences our decisions in today’s message-cluttered world? In Buyology, Martin Lindstrom presents the astonishing findings from his groundbreaking three-year, seven-million-dollar neuromarketing study—a cutting-edge experiment that peered inside the brains of 2,000 volunteers from all around the world as they encountered various ads, logos, commercials, brands, and products. His startling results shatter much of what we have long believed about what captures our interest—and drives us to buy. Among the questions he explores: • Does sex actually sell? • Does subliminal advertising still surround us? • Can “cool” brands trigger our mating instincts? • Can our other senses—smell, touch, and sound—be aroused when we see a product? Buyology is a fascinating and shocking journey into the mind of today's consumer that will captivate anyone who's been seduced—or turned off—by marketers' relentless attempts to win our loyalty, our money, and our minds.
Download or read book AGARD Conference Proceedings written by North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Discovering Reality written by Sandra Harding and published by Springer Science & Business Media. This book was released on 2005-12-30 with total page 431 pages. Available in PDF, EPUB and Kindle. Book excerpt: Are Western epistemology, metaphysics, methodology and the philosophy of science grounded only in men's distinctive understandings of themselves, others, and nature? Does this less than human understanding distort our models of reason and of scientific inquiry? In different ways, the papers in this collection explore the evidence for these increasingly reasonable and intriguing questions. They identify how it is distinctively masculine perspectives on masculine experience which have shaped the most fundamental and formal aspects of systematic thought in philosophy and the natural and social sciences - precisely the aspects of thought believed most gender-neutral. They show how these understandings ground Aristotle's biology and metaphysics; the very definition of the problems of philosophy in Plato, Descartes, Hobbes and Rousseau; the `adversary method' which is the paradigm of philosophic and scientific reasoning; principles of individuation in philosophical ontology and the philosophy of language; individualistic assumptions in psychology; functionalism in sociological and biological theory; evolutionary theory; the methodology of political science; Marxist political economy; and conceptions of `objective inquiry' in the social and natural sciences. These essays also begin to identify for us the distictive aspects of women's experience which can provide the resources needed for the creation of a truly human understanding. Audience: The book will be of interest to those involved in epistemology, and philosophy of the natural and social sciences, as well as feminist scholars in philosophy. The work will also be of value for theorists, methodologists, and feminist scholars in the natural and social sciences.
Download or read book Barriers to Innovation written by André Piatier and published by London ; Dover, N.H. : F. Pinter. This book was released on 1984 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt:
