Download or read book Etude et mod les effectifs d coulements quasi 2D written by Alban Pothérat and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Les ecoulements confines soumis a un fort champ magnetique vertical et les ecoulements en rotation autour d'un axe vertical presentent au moins deux caracteristiques communes marquantes : d'une part, le champ de vitesse est quasi-bidimensionnel loin des parois, et d'autre part, une couche limite de structure simple se developpe le long des parois perpendiculaires a la direction du champ magnetique (couche de hartmann) ou a l'axe de rotation (couche d'ekman). Nous presentons ici une etude de ces proprietes remarquables dans des cas ou les autres forces qui agissent sur l'ecoulement (inertie, viscosite,) ne sont plus negligeables devant la force de laplace ou de coriolis. Il est montre que la combinaison des couplages verticaux et horizontaux conduit d'une part, a une dependance quadratique du champ de vitesse en fonction de la verticale (effet tonneau), et d'autre part a la presence de jet dans les couches de hartmann ou d'ekman. Une loi de paroi analytique pour diverses configurations des couches de hartmann est construite (presence d'effets inertiels, presence d'une composante horizontale du champ magnetique, parois conductrices) dans le but d'eviter le maillage fin que requiert le calcul numerique direct d'une telle couche. Les proprietes remarquables des ecoulements quasi-2d sont ensuite utilisees pour construire trois modeles 2d differents, a partir de la moyenne verticale des equations du mouvement. Ces modeles simples, ne reposent que sur les hypotheses physiques et ne necessitent en particulier aucun etalonnage numerique. Le modele psm2000 pour les ecoulements mhdisavec inertie et sous fort champ vertical conduit a des resultats tres proches de l'experience et met notamment en evidence le fait que le pompage d'ekman dans les couches de hartmann se traduit approximativement par une diffusion du champ de vorticite le long des lignes de courant de l'ecoulement moyen. Un modele analogue, mais sans effets inertiels et avec un champ non homogene et instationnaire permet en premier lieu de determiner dans quel cas les couches de hartmann controlent l'ecoulement global et en second lieu, d'etudier la possibilite de controler un ecoulement d'acier liquide par un champ glissant dans un procede de coulee continue. Finalement, un modele quasi-geostrophique modifie fournit une base theorique pour l'etude du comportement des couches paralleles lors des experiences de spin-up et spin-down d'une cuve tournante.

Download or read book ETUDE ET MODELES EFFECTIFS D ECOULEMENTS QUASI 2D written by ALBAN.. POTHERAT and published by . This book was released on 2000 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt: LES ECOULEMENTS CONFINES SOUMIS A UN FORT CHAMP MAGNETIQUE VERTICAL ET LES ECOULEMENTS EN ROTATION AUTOUR D'UN AXE VERTICAL PRESENTENT AU MOINS DEUX CARACTERISTIQUES COMMUNES MARQUANTES : D'UNE PART, LE CHAMP DE VITESSE EST QUASI-BIDIMENSIONNEL LOIN DES PAROIS, ET D'AUTRE PART, UNE COUCHE LIMITE DE STRUCTURE SIMPLE SE DEVELOPPE LE LONG DES PAROIS PERPENDICULAIRES A LA DIRECTION DU CHAMP MAGNETIQUE (COUCHE DE HARTMANN) OU A L'AXE DE ROTATION (COUCHE D'EKMAN). NOUS PRESENTONS ICI UNE ETUDE DE CES PROPRIETES REMARQUABLES DANS DES CAS OU LES AUTRES FORCES QUI AGISSENT SUR L'ECOULEMENT (INERTIE, VISCOSITE,) NE SONT PLUS NEGLIGEABLES DEVANT LA FORCE DE LAPLACE OU DE CORIOLIS. IL EST MONTRE QUE LA COMBINAISON DES COUPLAGES VERTICAUX ET HORIZONTAUX CONDUIT D'UNE PART, A UNE DEPENDANCE QUADRATIQUE DU CHAMP DE VITESSE EN FONCTION DE LA VERTICALE (EFFET TONNEAU), ET D'AUTRE PART A LA PRESENCE DE JET DANS LES COUCHES DE HARTMANN OU D'EKMAN. UNE LOI DE PAROI ANALYTIQUE POUR DIVERSES CONFIGURATIONS DES COUCHES DE HARTMANN EST CONSTRUITE (PRESENCE D'EFFETS INERTIELS, PRESENCE D'UNE COMPOSANTE HORIZONTALE DU CHAMP MAGNETIQUE, PAROIS CONDUCTRICES) DANS LE BUT D'EVITER LE MAILLAGE FIN QUE REQUIERT LE CALCUL NUMERIQUE DIRECT D'UNE TELLE COUCHE. LES PROPRIETES REMARQUABLES DES ECOULEMENTS QUASI-2D SONT ENSUITE UTILISEES POUR CONSTRUIRE TROIS MODELES 2D DIFFERENTS, A PARTIR DE LA MOYENNE VERTICALE DES EQUATIONS DU MOUVEMENT. CES MODELES SIMPLES, NE REPOSENT QUE SUR LES HYPOTHESES PHYSIQUES ET NE NECESSITENT EN PARTICULIER AUCUN ETALONNAGE NUMERIQUE. LE MODELE PSM2000 POUR LES ECOULEMENTS MHDISAVEC INERTIE ET SOUS FORT CHAMP VERTICAL CONDUIT A DES RESULTATS TRES PROCHES DE L'EXPERIENCE ET MET NOTAMMENT EN EVIDENCE LE FAIT QUE LE POMPAGE D'EKMAN DANS LES COUCHES DE HARTMANN SE TRADUIT APPROXIMATIVEMENT PAR UNE DIFFUSION DU CHAMP DE VORTICITE LE LONG DES LIGNES DE COURANT DE L'ECOULEMENT MOYEN. UN MODELE ANALOGUE, MAIS SANS EFFETS INERTIELS ET AVEC UN CHAMP NON HOMOGENE ET INSTATIONNAIRE PERMET EN PREMIER LIEU DE DETERMINER DANS QUEL CAS LES COUCHES DE HARTMANN CONTROLENT L'ECOULEMENT GLOBAL ET EN SECOND LIEU, D'ETUDIER LA POSSIBILITE DE CONTROLER UN ECOULEMENT D'ACIER LIQUIDE PAR UN CHAMP GLISSANT DANS UN PROCEDE DE COULEE CONTINUE. FINALEMENT, UN MODELE QUASI-GEOSTROPHIQUE MODIFIE FOURNIT UNE BASE THEORIQUE POUR L'ETUDE DU COMPORTEMENT DES COUCHES PARALLELES LORS DES EXPERIENCES DE SPIN-UP ET SPIN-DOWN D'UNE CUVE TOURNANTE.

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 Solid Propellant Rocket Research written by Martin Summerfield and published by Elsevier. This book was released on 2013-11-11 with total page 713 pages. Available in PDF, EPUB and Kindle. Book excerpt: Solid Propellant Rocket Research

Download or read book Subsonic Aerodynamics written by Ion Paraschivoiu and published by Presses inter Polytechnique. This book was released on 2003 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Number System written by H. A. Thurston and published by Courier Corporation. This book was released on 2012-10-23 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book explores arithmetic's underlying concepts and their logical development, in addition to a detailed, systematic construction of the number systems of rational, real, and complex numbers. 1956 edition.

Download or read book A New Pocket Dictionary of the French and English Languages in Two Parts written by Thomas Nugent and published by . This book was released on 1770 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Structure of Atmospheric Turbulence written by John Leask Lumley and published by . This book was released on 1964 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Subsurface water Flow and Solute Transport written by and published by . This book was released on 1989 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Theory of Ionization of Gases by Collision written by Sir John Townsend and published by . This book was released on 1910 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book In Vessel Melt Retention and Ex Vessel Corium Cooling IAEA Tecdoc No 1906 written by International Atomic Energy Agency and published by International Atomic Energy Agency. This book was released on 2020-08-06 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: This publication results from a technical meeting on phenomenology and technologies relevant to in-vessel melt retention (IVMR) and ex-vessel corium cooling (EVCC). The purpose of the publication is to capture the state of knowledge, at the time of that meeting, related to phenomenology and technologies as well as the challenges and pending issues relevant to IVMR and EVCC for water cooled reactors by summarizing the information provided by the meeting participants in a form useful to practitioners in Member States.

Download or read book Mathematical Modeling in Optical Science written by Gang Bao and published by SIAM. This book was released on 2001-01-01 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume addresses recent developments in mathematical modeling in three areas of optical science: diffractive optics, photonic band gap structures, and waveguides. Particular emphasis is on the formulation of mathematical models and the design and analysis of new computational approaches. The book contains cutting-edge discourses on emerging technology in optics that provides significant challenges and opportunities for applied mathematicians, researchers, and engineers. Each of the three topics is presented through a series of survey papers to provide a broad overview focusing on the mathematical models. Chapters present model problems, physical principles, mathematical and computational approaches, and engineering applications corresponding to each of the three areas. Although some of the subject matter is classical, the topics presented are new and represent the latest developments in their respective fields.

Download or read book Advances in Rotorcraft Technology written by North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development. Flight Vehicle Integration Panel. Symposium and published by . This book was released on 1997 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Draft International Covenant on Environment and Development written by International Union for Conservation of Nature and Natural Resources. Commission on Environmental Law and published by IUCN. This book was released on 2000 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is an updated edition of the 1995 version. In the mid-1980's, the IUCN CEL, in consultation with leading experts from around the world, began to respond to a need later identified by Agenda 21: the preparation of an integrated framework for international environmental law.

Download or read book Satellite Situation Report written by Goddard Space Flight Center. Office of Public Affairs and published by . This book was released on 1977 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Waves in Nonlinear Pre Stressed Materials written by M. Destrade and published by Springer Science & Business Media. This book was released on 2007-11-08 with total page 287 pages. Available in PDF, EPUB and Kindle. Book excerpt: Papers in this book provide a state-of-the-art examination of waves in pre-stressed materials. You’ll gain new perspectives via a multi-disciplinary approach that interweaves key topics. These topics include the mathematical modeling of incremental material response (elastic and inelastic), an analysis of the governing differential equations, and boundary-value problems. Detailed illustrations help you visualize key concepts and processes.

Download or read book Limits for the Characteristic Roots of a Matrix written by Alfred Theodore Brauer and published by . This book was released on 1958 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the recently published book of E. Bodewig, Matrix Calculus some results of the earlier parts of this paper are mentioned. It is stated there that they are of theoretical interest, but have no practical value. In this paper it will be shown that they can easily be used for practical computations.