Download or read book Hydrodynamique et transfert de masse autour d une bulle confin e entre deux plaques written by Matthieu Roudet and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Ce travail de recherche est consacré à l'étude expérimentale de la dynamique d'une bulle isolée "bidimensionnelle", ainsi qu'à celle du transfert de masse de cette bulle vers la phase liquide pour le couple de fluides eau-oxygène. L'aspect bidimensionnel des bulles vient du fait qu'elles sont confinées entre 2 plaques. La gamme de nombres adimensionnels que nous avons balayée dans notre étude a été peu étudiée pour ce genre de dispositif. Dans cette étude, les effets inertiels lies à la perturbation de vitesse provoquée par le passage de la bulle ne sont pas négligeables devant le frottement aux parois. L'étude de l'hydrodynamique de la bulle est réalisée grâce à l'utilisation de techniques de mesure optique : ombroscopie et vélocimétrie par image laser (PIV). En raison de la géométrie 2D de la cellule, un éclairage en volume du champ d'investigation est réalisé pour les mesures PIV. Il est montré que la PIV mesure la vitesse moyenne du liquide dans l'épaisseur entre les plaques, lors du passage d'une bulle. Les mesures par ombroscopie permettent d'étudier la trajectoire et la forme de la bulle au cours du temps pour une large gamme de nombres de Reynolds (50-6000). On montre que la vitesse moyenne des bulles vérifie la loi d'échelle U = 0.5√gd compatible avec une interface non contaminée. D'autre part, l'étude de l'instabilité du mouvement et de la forme permet d'identifier différents régimes d'écoulement et notamment de montrer que la forme moyenne des bulles et la structure du sillage sont essentiels pour comprendre l'évolution des oscillations. De plus, les champs de vitesse issus de la PIV donnent l'évolution du sillage à l'arrière de la bulle en fonction du nombre d'Archimède et mettent en évidence deux structures clairement différentes, suivant que les bulles sont des calottes avec une trajectoire rectiligne, ou des ellipsoïdes qui oscillent. Ils montrent également que, quelque soit le nombre de Reynolds, le sillage décroît rapidement à cause du confinement. L'étude du transfert de l'oxygène, contenu dans la bulle, vers le liquide, est réalisée au moyen de la technique de fluorescence induite par nappe laser (PLIF), avec inhibition de la fluorescence par l'oxygène dissous, et avec un éclairage en volume de la cellule. L'analyse des images de fluorescence permet de distinguer le transfert de matière issu de deux régions de l'interface de la bulle : la surface en contact avec les films liquides entre la bulle et les plaques, et la surface périphérique de la bulle. Le transfert de masse par les films se faisant dans un espace mince et proche des parois, l'oxygène n'est pas réparti de manière uniforme dans l'épaisseur aux temps courts après le passage de la bulle. La non linéarité du signal de fluorescence avec la concentration en oxygène implique de prendre en compte la répartition de l'oxygène entre les plaques. Un modèle de répartition de l'oxygène entre les plaques est proposé, et confronté à des mesures de concentration entre les plaques après diffusion ; cette démarche permet de déterminer la contribution relative des deux surfaces au transfert. Les flux de matière ainsi que les densités de flux issus de chacune des deux régions de la surface de la bulle sont calculés et discutés.

Download or read book Contribution l tude de l hydrodynamique et du transfert de mati re dans une colonne bulles en ascension libre written by Piyasan Praserthdam (auteur d'une thèse de sciences.) and published by . This book was released on 1979 with total page 131 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Hydrodynamique et transfert gaz liquide non newtonien en fluidisation triphasique written by Touraj Tavakoli Gheynani and published by . This book was released on 1989 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: LA FLUIDISATION GAZ-LIQUIDE-SOLIDE EST ETUDIEE EXPERIMENTALEMENT DU POINT DE VUE HYDRODYNAMIQUE (VITESSE MINIMALE, EXPANSION, RETENTIONS DU LIQUIDE ET DU GAZ) ET DU POINT DE VUE TRANSFERT DE MATIERE PAR ABSORPTION D'OXYGENE. LES MESURES HYDRODYNAMIQUES SONT EFFECTUEES AVEC DIVERS LIQUIDES NEWTONIENS ET NON NEWTONIENS ET PAR ANALOGIE ON DETERMINE UNE VISCOSITE APPARENTE. PAR RAPPORT A L'EAU, L'ECOULEMENT EST PROFONDEMENT MODIFIE PAR LA COALESCENCE QUI PRODUIT UN REGIME A BULLES DEFORMEES OU A BOUCHONS. CEPENDANT, LES RETENTIONS SONT ASSEZ PEU INFLUENCEES PAR LA VISCOSITE DE MEME QUE PAR LE DIAMETRE DES PARTICULES. EN TRANSFERT DE MATIERE, LES PROFILS DE CONCENTRATION EN OXYGENE DISSOUS SONT TRAITES PAR LE MODELE A DISPERSION AXIALE ET FOURNISSENT LES COEFFICIENTS CARACTERISTIQUES, DE LA DISPERSION AXIALE ET DU TRANSFERT VOLUMETRIQUE. L'ACCROISSEMENT DE VISCOSITE SE TRADUIT ESSENTIELLEMENT PAR UNE FORTE REDUCTION DU COEFFICIENT VOLUMETRIQUE DE TRANSFERT EN RAISON DE LA REDUCTION D'AIRE INTERFACIALE. PAR CONTRE, L'INFLUENCE DE LA VITESSE DE GAZ RESTE TRES IMPORTANTE. LE MODELE PEUT ETRE AMELIORE PAR LA PRISE EN COMPTE DE LA COALESCENCE, PAR L'INTERMEDIAIRE D'UNE REDUCTION AXIALE EXPONENTIELLE DE CE COEFFICIENT VOLUMETRIQUE

Download or read book Analyse exp rimentale et mod lisation du transfert de mati re et du m lange dans une couche cisaill e bulles written by Hamdi Ayed and published by . This book was released on 2007 with total page 199 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this work we develop a Eulerian two-fluids model for hydrodynamics and mass transfer in turbulent bubbly flows. We study oxygen-water mixing layers for void fractions 2

Download or read book Basic Technics in Ecological Farming Techniques de Base en Agriculture Biologique Grunds tzliche Verfahren der kologischen Landwirtschaft Le Maintien de la Fertilit des Sols The Maintenance of Soil Fertility Die Erhaltung der Bodenfruchtbarkeit written by Stuart Hill and published by Birkhäuser. This book was released on 2013-12-14 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Acoustics Aeroacoustics and Vibrations written by Fabien Anselmet and published by John Wiley & Sons. This book was released on 2016-01-07 with total page 529 pages. Available in PDF, EPUB and Kindle. Book excerpt: This didactic book presents the main elements of acoustics, aeroacoustics and vibrations. Illustrated with numerous concrete examples linked to solid and fluid continua, Acoustics, Aeroacoustics and Vibrations proposes a selection of applications encountered in the three fields, whether in room acoustics, transport, energy production systems or environmental problems. Theoretical approaches enable us to analyze the different processes in play. Typical results, mostly from numerical simulations, are used to illustrate the main phenomena (fluid acoustics, radiation, diffraction, vibroacoustics, etc.).

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 Faecal Sludge Management written by Linda Strande and published by IWA Publishing. This book was released on 2014-08-15 with total page 428 pages. Available in PDF, EPUB and Kindle. Book excerpt: It is estimated that literally billions of residents in urban and peri-urban areas of Africa, Asia, and Latin America are served by onsite sanitation systems (e.g. various types of latrines and septic tanks). Until recently, the management of faecal sludge from these onsite systems has been grossly neglected, partially as a result of them being considered temporary solutions until sewer-based systems could be implemented. However, the perception of onsite or decentralized sanitation technologies for urban areas is gradually changing, and is increasingly being considered as long-term, sustainable options in urban areas, especially in low- and middle-income countries that lack sewer infrastructures. This is the first book dedicated to faecal sludge management. It compiles the current state of knowledge of the rapidly evolving field of faecal sludge management, and presents an integrated approach that includes technology, management, and planning based on Sandecs 20 years of experience in the field. Faecal Sludge Management: Systems Approach for Implementation and Operation addresses the organization of the entire faecal sludge management service chain, from the collection and transport of sludge, and the current state of knowledge of treatment options, to the final end use or disposal of treated sludge. The book also presents important factors to consider when evaluating and upscaling new treatment technology options. The book is designed for undergraduate and graduate students, and engineers and practitioners in the field who have some basic knowledge of environmental and/or wastewater engineering.

Download or read book Boundary Layer Theory written by Hermann Schlichting (Deceased) and published by Springer. This book was released on 2016-10-04 with total page 814 pages. Available in PDF, EPUB and Kindle. Book excerpt: This new edition of the near-legendary textbook by Schlichting and revised by Gersten presents a comprehensive overview of boundary-layer theory and its application to all areas of fluid mechanics, with particular emphasis on the flow past bodies (e.g. aircraft aerodynamics). The new edition features an updated reference list and over 100 additional changes throughout the book, reflecting the latest advances on the subject.

Download or read book Food Process Engineering written by Dennis R. Heldman and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 441 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Second Edition of Food Process Engineering by Dr. Dennis Heldman, my former student, and co-author Paul Singh, his former student, attests to the importance of the previous edition. In the Foreword to the First Edition, I noted the need for people in all facets of the food processing industry to consider those variables of design of particular importance in engineering for the food processing field. In addition to recognizing the many variables involved in the biological food product being handled from production to consumption, the engi neer must oftentimes adapt equations developed for non-biological materials. As more and more research is done, those equations are appropriately modified to be more accurate or new equations are developed specifically for designing to process foods. This Edition updates equations used. This book serves a very important need in acquainting engineers and technologists, particularly those with a math ematics and physics background, with the information necessary to provide a more efficient design to accomplish the objectives. Of prime importance, at present and in the future, is to design for efficient use of energy. Now, it is often economical to put considerably more money into first costs for an efficient design than previously, when energy costs were a much smaller proportion of the total cost of process engineering.

Download or read book A Parallel Finite Volume Algorithm for Large eddy Simulation of Turbulent Flows written by Trong T. Bui and published by . This book was released on 1998 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fundamentals of Latex Film Formation written by Joseph Keddie and published by Springer Science & Business Media. This book was released on 2010-02-18 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book has emerged out of our long-time research interests on the topic of latex film formation. Over the years we have built up a repertoire of slides used in conference presentations, short courses and tutorials on the topic. The story presented in this book has thereby taken shape as it has been told and re-told to a mix of academic and industrial audiences. The book presents a wide body of work accumulated by the polymer colloids community over the past five decades, but the selection of examples has been flavoured by our particular experimental interests and development of mathematical models. We intend the book to be a starting point for academic and industrial scientists beginning research on latex film formation. The emphasis is on fundam- tal mechanisms, however, and not on applications nor on specific effects of formu- tions. We hope that the book consolidates the understanding that has been achieved to-date in the literature in a more comprehensive way than is possible in a review article. We trust that the reader will appreciate the fascination of the topic.

Download or read book Cellular Automata Modeling of Physical Systems written by Bastien Chopard and published by Cambridge University Press. This book was released on 2005-06-30 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a self-contained introduction to cellular automata and lattice Boltzmann techniques. Beginning with a chapter introducing the basic concepts of this developing field, a second chapter describes methods used in cellular automata modeling. Following chapters discuss the statistical mechanics of lattice gases, diffusion phenomena, reaction-diffusion processes and non-equilibrium phase transitions. A final chapter looks at other models and applications, such as wave propagation and multiparticle fluids. With a pedagogic approach, the volume focuses on the use of cellular automata in the framework of equilibrium and non-equilibrium statistical physics. It also emphasises application-oriented problems such as fluid dynamics and pattern formation. The book contains many examples and problems. A glossary and a detailed bibliography are also included. This will be a valuable book for graduate students and researchers working in statistical physics, solid state physics, chemical physics and computer science.

Download or read book Granular Materials written by S Joseph Antony and published by Royal Society of Chemistry. This book was released on 2007-10-31 with total page 385 pages. Available in PDF, EPUB and Kindle. Book excerpt: Granular materials play an important role in many industries. Continuous ingenuity and advancement in these industries necessitates the ability to predict the fundamental behaviour of granular materials under different working environments. With contributions from international experts in the field Granular Materials; Fundamentals and Applications details recent advances made in theoretical computational and experimental approaches in understanding the behaviour of granular materials including industrial applications. Topics covered include: * key features of granular plasticity * high temperature particle interactions * influence of polymers on particulate dispersion stability: scanning probe microscopy investigations * in-process measurement of particulate systems Presented by world renowned researchers this book will be welcomed by scientists and engineers working across a wide spectrum of engineering disciplines.

Download or read book How to Design Wastewater Systems for Local Conditions in Developing Countries written by David M. Robbins and published by IWA Publishing. This book was released on 2014-03-15 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a practical handbook providing a step-by-step approach to the techniques used for characterizing wastewater sources and investigating sites where collection, treatment and reuse/disposal technologies will be installed. It is intended to help enable local implementation of on-site and decentralized wastewater management system (DWMS)for wide scale use in development settings. How to Design Wastewater Systems for Local Conditions in Developing Countries helps local service providers and regulatory officials make informed decisions through the use of tools, checklists and case studies. It includes a link to a web based community of on-site and decentralized wastewater professionals, which contains related tools and case studies. This handbook serves as a reference for training classes, certification programs, and higher education programs in civil and sanitary engineering. There is an increasing interest on the part of local government officials and private sector service providers to implement wastewater treatment systems to solve sanitation problems. The model presented in this handbook promotes activities that first generate data related to source and site conditions that represent critical inputs, and then applies this information to the technology selection process. Matching the most appropriate technologies to the specific needs of the wastewater project is the key that leads to long term sustainability. How to Design Wastewater Systems for Local Conditions in Developing Countries is an invaluable resource for public sector decision makers and private sector service providers in developing countries. It is also a useful text for students at engineering colleges in developing countries interested in taking a class that teaches the methods of decentralized wastewater management system (DWMS) development.

Download or read book Compendium of Sanitation Systems and Technologies written by Elizabeth Tilley and published by . This book was released on 2014 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Desalination written by Jane Kucera and published by John Wiley & Sons. This book was released on 2019-04-16 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: “Blue is the new green.” This is an all-new revised edition of a modern classic on one of the most important subjects in engineering: Water. Featuring a total revision of the initial volume, this is the most comprehensive and up-to-date coverage of the process of desalination in industrial and municipal applications, a technology that is becoming increasingly more important as more and more companies choose to “go green.” This book covers all of the processes and equipment necessary to design, operate, and troubleshoot desalination systems, from the fundamental principles of desalination technology and membranes to the much more advanced engineering principles necessary for designing a desalination system. Earlier chapters cover the basic principles, the economics of desalination, basic terms and definitions, and essential equipment. The book then goes into the thermal processes involved in desalination, such as various methods of evaporation, distillation, recompression, and multistage flash. Following that is an exhaustive discussion of the membrane processes involved in desalination, such as reverse osmosis, forward osmosis, and electrodialysis. Finally, the book concludes with a chapter on the future of these technologies and their place in industry and how they can be of use to society. This book is a must-have for anyone working in water, for engineers, technicians, scientists working in research and development, and operators. It is also useful as a textbook for graduate classes studying industrial water applications.