Download or read book ECOULEMENT TRANSITOIRE EN CONDUITE ET MODELISATION DES PHENOMENES DE CAVITATION written by ABDELMJID.. QADI EL IDRISSI and published by . This book was released on 1996 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: CETTE ETUDE EST CONSACREE AU PHENOMENE DE CAVITATION LORS DE LA FERMETURE BRUSQUE D'UNE VANNE SITUEE EN AMONT OU EN AVAL D'UNE CONDUITE OU S'ECOULE DE L'EAU EN PRESENCE DE GAZ DISSOUS (AIR OU GAZ CARBONIQUE). LA PLUPART DES MODELES PROPOSES ANTERIEUREMENT, CONSIDERENT LE MELANGE LIQUIDE/GAZ COMME UN ECOULEMENT DIPHASIQUE A BULLES SANS GLISSEMENT, CECI POUR SIMPLIFIER LA MODELISATION DU PROBLEME. LE BUT DE NOTRE TRAVAIL EST DE TENIR COMPTE DE LA DIFFERENCE DE VITESSE ENTRE LES DEUX PHASES AFIN DE DETERMINER L'INFLUENCE DE CE PARAMETRE. LE MODELE MATHEMATIQUE PRESENTE EST UN SYSTEME HYPERBOLIQUE NON LINEAIRE TRADUISANT LA CONSERVATION DE MASSE DES DEUX PHASES, LA CONSERVATION DE QUANTITE DE MOUVEMENT DU MELANGE ET UNE EQUATION DE GLISSEMENT EXPRIMANT LA VITESSE DES BULLES DE GAZ PAR RAPPORT AU FLUIDE, LE DEGAZAGE ETANT MODELISE PAR LA LOI DE HENRY. LA FORME NON CONSERVATIVE DE CE MODELE DUE A L'EQUATION DE GLISSEMENT, EXCLUT TOUTE POSSIBILITE D'APPLIQUER LES METHODES NUMERIQUES CLASSIQUES. NOUS PROPOSONS DONC UN SCHEMA DE CALCUL SPECIFIQUE AUX DIFFERENCES FINIES AINSI QU'UN TRAITEMENT NUMERIQUE PARTICULIER DES CONDITIONS AUX LIMITES. A TITRE DE TEST, CETTE METHODE A ETE VALIDEE DANS LE CAS PARTICULIER DU PROBLEME DE RIEMANN ASSOCIE AU MODELE SANS GLISSEMENT. LES RESULTATS NUMERIQUES OBTENUS SONT COMPATIBLES AVEC LES DIVERS RESULTATS EXPERIMENTAUX TIRES DE LA LITTERATURE
Download or read book Modelisation en coulement homog ne des ph nom nes de cavitation lors des r gimes transitoires en conduite written by Mohand Kessal and published by . This book was released on 1987 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: L'étude présentée est consacrée à l'analyse des phénomènes de cavitation en régime transitoire en conduite élastique pour un mélange homogène liquide-gaz. Dans l'hypothèse où-les deux constituants ont même vitesse, il est mis en évidence la possibilité de modéliser l'écoulement tout en conservant dans les relations, le caractère continu,en moyenne, du milieu,c'est-à-dire sans prendre en compte le phénomène de"rupture de veine ». La résolution du système d'équations a été obtenue soit par différences finies classiques (schéma de Mac CORMACK), soit à partir de la méthode des caractéristiques (méthode de HARTREE). La comparaison des résultats ainsi obtenus, avec des données expérimentales, a confirmé la validité de la modélisation proposée. Enfin a été également examine le cas où les deux phases ont des vitesses différentes avec l'établissement d'une formulation générale sous forme caractéristique.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1988 with total page 968 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book laboration d algorithmes de calcul des coulements transitoires en conduites dans les m langes de liquides et de gaz written by Ezzedine Hadj Taieb (auteur d'une thèse de sciences.) and published by . This book was released on 1977 with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Use of Services for Family Planning and Infertility United States 1982 written by Gerry E. Hendershot and published by . This book was released on 1988 with total page 982 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 1982 statistics on the use of family planning and infertility services presented in this report are preliminary results from Cycle III of the National Survey of Family Growth (NSFG), conducted by the National Center for Health Statistics. Data were collected through personal interviews with a multistage area probability sample of 7969 women aged 15-44. A detailed series of questions was asked to obtain relatively complete estimates of the extent and type of family planning services received. Statistics on family planning services are limited to women who were able to conceive 3 years before the interview date. Overall, 79% of currently mrried nonsterile women reported using some type of family planning service during the previous 3 years. There were no statistically significant differences between white (79%), black (75%) or Hispanic (77%) wives, or between the 2 income groups. The 1982 survey questions were more comprehensive than those of earlier cycles of the survey. The annual rate of visits for family planning services in 1982 was 1077 visits /1000 women. Teenagers had the highest annual visit rate (1581/1000) of any age group for all sources of family planning services combined. Visit rates declined sharply with age from 1447 at ages 15-24 to 479 at ages 35-44. Similar declines with age also were found in the visit rates for white and black women separately. Nevertheless, the annual visit rate for black women (1334/1000) was significantly higher than that for white women (1033). The highest overall visit rate was for black women 15-19 years of age (1867/1000). Nearly 2/3 of all family planning visits were to private medical sources. Teenagers of all races had higher family planning service visit rates to clinics than to private medical sources, as did black women age 15-24. White women age 20 and older had higher visit rates to private medical services than to clinics. Never married women had higher visit rates to clinics than currently or formerly married women. Data were also collected in 1982 on use of medical services for infertility by women who had difficulty in conceiving or carrying a pregnancy to term. About 1 million ever married women had 1 or more infertility visits in the 12 months before the interview. During the 3 years before interview, about 1.9 million women had infertility visits. For all ever married women, as well as for white and black women separately, infertility services were more likely to be secured from private medical sources than from clinics. The survey design, reliability of the estimates and the terms used are explained in the technical notes.
Download or read book La cavitation written by Jean-Pierre Franc and published by Presses Universitaires de Grenoble. This book was released on 1995 with total page 588 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Annual Index written by and published by . This book was released on 1988 with total page 1424 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Annual Index Keyword A L written by and published by . This book was released on 1988 with total page 1600 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book tude du couplage coulement mouvement pour des corps solides ou d formation impos e par r solution des quations de Navier Stokes written by Alban Leroyer and published by . This book was released on 2004 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: On s'intéresse dans ce travail de thèse à l'ajout de deux phénomènes physiques qui se couplent à la résolution des équations de Navier-Stokes en moyenne de Reynolds. Le premier concerne les mouvements de corps solides ou déformables à déformation imposée. Les différentes méthodes numériques spécifiques pour mener à bien de telles simulations sont exposées : résolution du Principe Fondamental de la Dynamique, stratégies de remaillage, couplage écoulement/mouvement, discrétisation des équations,... Plusieurs applications sont ensuite présentées, principalement dans le domaine hydrodynamique (tenue à la mer, impact sur une surface libre, écoulement autour d'une palette d'aviron). Une application plus orientée vers la biohydrodynamique, intégrée au Projet Interdisciplinaire de Recherche ROBEA, montre une étude mettant en jeu un corps déformable. Ainsi, les premiers calculs tridimensionnels recensés couplant la résolution du Principe Fondamental de la Dynamique avec celle des équations de Navier-Stokes sur un robot-anguille auto-propulsé sont décrits dans ce mémoire. Le second apport en terme de nouveaux phénomènes physiques concerne la modélisation numérique de la cavitation. Cette extension des écoulements multi-phases a consisté à intégrer un modèle de production-destruction de vapeur sans recourir à de lourdes modifications dans le solveur Navier-Stokes. Les premiers résultats ainsi que les dificultés numériques de résolution sont exposés. Pour s'affranchir de ces problèmes numériques, une nouvelle formulation offrant un couplage plus fort entre les différentes variables est finalement proposée
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1988 with total page 988 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Optimisation des tats de surface et nouveau mod le de cavitation pour un coulement lubrifi written by Eric Dalissier and published by . This book was released on 2012 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book CONTRIBUTION A LA MODELISATION EN LUBRIFICATION HYDRODYNAMIQUE written by MICHELE.. CHAMBAT WEITZ and published by . This book was released on 1987 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: ANALYSE NUMERIQUE EN LUBRIFICATION HYDRODYNAMIQUE AVEC CAVITATION. EQUATIONS AUX DERIVEES PARTIELLES, METHODES ASYMPTOTIQUES, PROBLEMES DE FRONTIERES LIBRES ET HOMOGENEISATION. INFLUENCE DE LA RUGOSITE DE SURFACE
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 Advances in Hydroinformatics written by Philippe Gourbesville and published by Springer Science & Business Media. This book was released on 2013-11-12 with total page 545 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book is a collection of extended papers which have been selected for presentation during the SIMHYDRO 2012 conference held in Sophia Antipolis in September 2012. The papers present the state of the art numerical simulation in domains such as (1) New trends in modelling for marine, river & urban hydraulics; (2) Stakeholders & practitioners of simulation; (3) 3D CFD & applications. All papers have been peer reviewed and by scientific committee members with report about quality, content and originality. The target audience for this book includes scientists, engineers and practitioners involved in the field of numerical modelling in the water sector: flood management, natural resources preservation, hydraulic machineries, and innovation in numerical methods, 3D developments and applications.
Download or read book Bogoliubov de Gennes Method and Its Applications written by Jian-Xin Zhu and published by Springer. This book was released on 2016-06-21 with total page 193 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this book is to provide an elementary yet systematic description of the Bogoliubov-de Gennes (BdG) equations, their unique symmetry properties and their relation to Green’s function theory. Specifically, it introduces readers to the supercell technique for the solutions of the BdG equations, as well as other related techniques for more rapidly solving the equations in practical applications. The BdG equations are derived from a microscopic model Hamiltonian with an effective pairing interaction and fully capture the local electronic structure through self-consistent solutions via exact diagonalization. This approach has been successfully generalized to study many aspects of conventional and unconventional superconductors with inhomogeneities – including defects, disorder or the presence of a magnetic field – and becomes an even more attractive choice when the first-principles information of a typical superconductor is incorporated via the construction of a low-energy tight-binding model. Further, the lattice BdG approach is essential when theoretical results for local electronic states around such defects are compared with the scanning tunneling microscopy measurements. Altogether, these lectures provide a timely primer for graduate students and non-specialist researchers, while also offering a useful reference guide for experts in the field.
Download or read book Advances in Hydroinformatics written by Philippe Gourbesville and published by Springer. This book was released on 2015-08-21 with total page 616 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a collection of extended papers based on presentations given during the SIMHYDRO 2014 conference, held in Sophia Antipolis in June 2014. It focuses on the modeling and simulation of fast hydraulic transients, on 3D modeling, and on uncertainties and multiphase flows. The book explores both the limitations and performance of current models and presents the latest developments based on new numerical schemes, high-performance computing, multiphysics and multiscale methods, and better interaction with field or scale model data. It addresses the interests of practitioners, stakeholders, researchers and engineers active in this field.
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.
