Download or read book Experimental and Numerical Studies of Open channel Turbulent Flow Over Rough Bed written by 王宪業 and published by . This book was released on 2010 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Turbulent Open Channel Flow Sediment Erosion and Sediment Transport written by Clemens Chan-Braun and published by KIT Scientific Publishing. This book was released on 2014-07-30 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis aims to contribute to a better understanding of turbulent open channel flow, sediment erosion and sediment transport. The thesis provides an analysis of high-fidelity data from direct numerical simulation of (i) open channel flow over an array of fixed spheres, (ii) open channel flow with mobile eroding spheres, (iii) open channel flow with sediment transport of many mobile spheres. An immersed boundary method is used to resolve the finite-size particles.

Download or read book Experimental and Numerical Studies of Complex Open Channel Flows written by 楊青遠 and published by . This book was released on 2012 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Turbulence in Open Channel Flows written by Hiroji Nakagawa and published by Routledge. This book was released on 2017-10-02 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: A review of open channel turbulence, focusing especially on certain features stemming from the presence of the free surface and the bed of a river. Part one presents the statistical theory of turbulence; Part two addresses the coherent structures in open-channel flows and boundary layers.

Download or read book Turbulence In Coastal And Civil Engineering written by B Mutlu Sumer and published by World Scientific. This book was released on 2020-03-23 with total page 758 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses the subject of turbulence encountered in coastal and civil engineering.The primary aim of the book is to describe turbulence processes including transition to turbulence; mean and fluctuating flows in channels/pipes, and in currents; wave boundary layers (including boundary layers under solitary waves); streaming processes in wave boundary layers; turbulence processes in breaking waves including breaking solitary waves; turbulence processes such as bursting process and their implications for sediment transport; flow resistance in steady and wave boundary layers; and turbulent diffusion and dispersion processes in the coastal and river environment, including sediment transport due to diffusion/dispersion.Both phenomenological and statistical theories are described in great detail. Turbulence modelling is also described, and several examples for modelling of turbulence in steady flow and wave boundary layers are presented.The book ends with a chapter containing hands-on exercises on a wide variety of turbulent flows including experimental study of turbulence in an open-channel flow, using Laser Doppler Anemometry; Statistical, correlation and spectral analysis of turbulent air jet flow; Turbulence modelling of wave boundary layer flows; and numerical modelling of dispersion in a turbulent boundary layer, a set of exercises used by the authors in their Masters classes over many years.Although the book is essentially intended for professionals and researchers in the area of Coastal and Civil Engineering, and as a text book for graduate/post graduate students, the contents of the book will, however, additionally provide sufficient background in the study of turbulent flows relevant to many other disciplines, such as Wind Engineering, Mechanical Engineering, and Environmental Engineering.

Download or read book Large Eddy Simulation of Rough Surface Flow in Shallow Open Channels written by Zeng Zhang and published by . This book was released on 2018 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt: Open channels often have a rough bed surface. A good understanding of the characteristics of water flow over the rough bed is important for many applications in hydraulic engineering. Examples include investigations of the re-suspension and transport of contaminated bed materials, channel erosion, and the effectiveness of dissipating excessive flow energy. In this thesis, the rough surface was created by placing transverse bars at a flat channel-bed in one case and cubes in the other case, and the velocity field of rough-surface flow was computed through large eddy simulations (LES). This thesis aims to evaluate suitable computing strategies, validate computational results using available experimental data, and explore the detailed structures of near-bed flow. On the basis of the bars centre-to-centre spacing, , relative to their vertical dimension, k, studies of the rough-surface flow classify the rough elements as k-type and d-type ribs. Previous experimental studies of the rough-surface flow have produced some measurements of flow velocities, provided assessments of the suitability of existing methods for determining the shear velocity, and comparisons of characteristics between flow over d-type ribs and that over smooth walls, as well as between flow over ribs and that over transverse rows of staggered cubes. The main findings were that similarities existed in the outer layer between flow over three-dimensional roughness and flow over smooth walls. Some previous numerical studies introduced a form-drag term in the momentum equation to indirectly allow for the effect of roughness on the flow. Other numerical studies used obstacles as bed roughness elements, and applied non-slip conditions at their surfaces. A significant limitation of the previous studies is the use of conditions of fully developed boundary layer flow with zero-pressure gradient. This would be very approximate for water flows in shallow open channels. The canonical turbulent boundary layers are not expected to be valid, because the boundary layer thickness is a significant fraction of the depth of flow. Further investigations of the flow characteristics are needed. The large eddy simulations reported in this thesis capture the flow characteristics in the near-bed region. They gave numerical predictions of the flow field over transverse bars in shallow open channels at a range of /k ratios. The predictions provide accurate horizontal turbulence intensities, and horizontal velocity. It seems that large eddy simulations produce accurate flow characteristics in the streamwise direction, but less accurate results in the vertical direction. A plausible reason is the side wall effects. It is challenging to realistically capture secondary flow that creates transverse vortices in the transverse direction on both sides of the channel. These vortices cause upward motions at the middle of the channel. The power spectrum density (PSD) curves for all the runs show characteristics of energy cascade that are consistent with the results reported in the literature (Rodi, 2017), in particular the energy distribution for the inertia subrange. It has been concluded that: 1) an increase in the n/k ratio leads to a decrease in the region of reverse flow within the cavity, and an increase in the shear stress on the upstream face of transverse bars; 2) in the case of flow over staggered cubes, they tend to restrict reverse flow, and cause the shear stress at the upstream edge of the cubes to increase; 3) it is suitable to apply cyclic boundary conditions in both the transverse and streamwise directions in simulations of fully developed flow.

Download or read book Boundary Layer Flows written by Vallampati Ramachandra Prasad and published by BoD – Books on Demand. This book was released on 2020-01-22 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by experts in the field, this book, "Boundary Layer Flows - Theory, Applications, and Numerical Methods" provides readers with the opportunity to explore its theoretical and experimental studies and their importance to the nonlinear theory of boundary layer flows, the theory of heat and mass transfer, and the dynamics of fluid. With the theory's importance for a wide variety of applications, applied mathematicians, scientists, and engineers - especially those in fluid dynamics - along with engineers of aeronautics, will undoubtedly welcome this authoritative, up-to-date book.

Download or read book Aquananotechnology written by David E. Reisner and published by CRC Press. This book was released on 2014-09-24 with total page 1370 pages. Available in PDF, EPUB and Kindle. Book excerpt: The world’s fresh water supplies are dwindling rapidly—even wastewater is now considered an asset. By 2025, most of the world's population will be facing serious water stresses and shortages. Aquananotechnology: Global Prospects breaks new ground with its informative and innovative introduction of the application of nanotechnology to the remediation of contaminated water for drinking and industrial use. It provides a comprehensive overview, from a global perspective, of the latest research and developments in the use of nanotechnology for water purification and desalination methods. The book also covers approaches to remediation such as high surface area nanoscale media for adsorption of toxic species, UV treatment of pathogens, and regeneration of saturated media with applications in municipal water supplies, produced water from fracking, ballast water, and more. It also discusses membranes, desalination, sensing, engineered polymers, magnetic nanomaterials, electrospun nanofibers, photocatalysis, endocrine disruptors, and Al13 clusters. It explores physics-based phenomena such as subcritical water and cavitation-induced sonoluminescence, and fog harvesting. With contributions from experts in developed and developing countries, including those with severe contamination, such as China, India, and Pakistan, the book’s content spans a wide range of the subject areas that fall under the aquananotechnology banner, either squarely or tangentially. The book strongly emphasizes sorption media, with broad application to a myriad of contaminants—both geogenic and anthropogenic—keeping in mind that it is not enough for water to be potable, it must also be palatable.

Download or read book Scalar Dispersion in Turbulent Open Channel Flows Over Smooth and Rough Beds written by Zhuo Chen and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Study of passive dispersion of a neutral scalar in turbulentflows is highly important due to its numerous applications in the areas of turbulent flow visualization, turbulent heat transfer and transport of pollutants and other substances in the environment. Over the past few decades, many analytical, numerical, and experimental studies have been conducted on this topic to obtain a better understanding of the physical process. In the present work, Large Eddy Simulations (LES) of scalar dispersion in turbulent flow over smooth and rough channels is conducted to contribute to the further understanding of the relation between the turbulent velocity field and the concentration field. The LES results from the present work showed good agreement with a recently com-pleted experimental study(Rahman and Webster [2005]). An in-depth comparison of in-stantaneous concentration and velocity fields revealed thecorrelation between scalar dis-persion and coherent structures of the turbulent flow. Also, a three dimensional visual-ization of concentration iso-surfaces at different instants provided a good picture of the concentration structures transported as a result of hairpin vortices of turbulent flow, which is quite difficult to accomplish using experimental studies.

Download or read book Experimental and Numerical Studies of Turbulent Cross flow in a Staggered Tube Bundle written by Samuel Sunday Paul and published by . This book was released on 2007 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Experimental and Numerical Investigation of Developing Turbulent Flow Over a Wavy Wall written by Vinicius Martins Segunda and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Turbulent flow over a wavy wall in a horizontal channel is investigated by experimental and numerical methods. The thorough problem understanding can advance turbulent flow physics knowledge for separating and reattaching flows. Another important consideration is the performance evaluation of mathematical models used in computational fluid dynamics (CFD) codes to predict the flow characteristics. This study explores numerical models because they are critically important to the design and performance evaluation of engineering systems. The experimental data are obtained to provide repository data and more insights into the flow physics considering both the flow development and fully periodic regions. A channel with a wavy bottom wall is considered for this study, and its main characteristic is a value of 10 for the ratio between the wave length and wave amplitude. A high-resolution particle image velocimetry (PIV) system is used to obtain detailed measurements of velocity at Reynolds number of 5040, 8400, 10700 and 13040 in both the developing and fully periodic regions. The numerical simulations are performed with a commercial CFD code using four eddy viscosity turbulence models and three Second-Moment Closure (SMC) turbulence models. This work assessed the predictive accuracy of a total of seven turbulence models. The experimental study covered a lack of data for the flow development within the waves, prior the periodic condition region, and it supported the turbulence models evaluation. The experiments provided features of the flow such as the recirculation regions, Reynolds stresses, and turbulent kinetic energy production at different channel locations. A comprehensive comparison between models and experimental data revealed a significant dependency on the turbulence model formulation and on the wall treatment selection for the flow development and fully periodic regions predictions.

Download or read book Numerical and Experimental Investigation of Turbulent Open Channel Flows Over Bed Forms written by Fei Gao and published by . This book was released on 2000 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Hydrodynamic and Mass Transport at Freshwater Aquatic Interfaces written by Paweł Rowiński and published by Springer. This book was released on 2016-01-27 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents selected contributions of the 34th International School of Hydraulics that was held in May 2015 in Zelechów, Poland. It gives an overview about the state of the art in environmental hydraulics. A special emphasis is put upon physical, biochemical and ecological processes that act at interfaces in natural surface water bodies but also other important hydraulic problems are considered. The achievements of well-known researchers from all over the world as well as the results obtained by young researchers, among others within a Marie Curie funded Initial Training Network, led by the University of Padua (HYTECH - HYdrodynamic Transport at Ecologically Critical Heterogeneous Interfaces) are gathered in this volume.

Download or read book Large Eddy Simulation in Hydraulics written by Wolfgang Rodi and published by CRC Press. This book was released on 2013-06-27 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: An introduction to the Large-Eddy-Simulation (LES) method, geared primarily toward hydraulic and environmental engineers, the book covers special features of flows in water bodies and summarizes the experience gained with LES for calculating such flows. It can also be a valuable entry to the subject of LES for researchers and students in all fields of fluids engineering, and the applications part will be useful to researchers interested in the physics of flows governed by the dynamics of coherent structures.

Download or read book Informatics Networking and Intelligent Computing written by Jiaxing Zhang and published by CRC Press. This book was released on 2015-05-06 with total page 2590 pages. Available in PDF, EPUB and Kindle. Book excerpt: This proceedings volume contains selected papers presented at the 2014 International Conference on Informatics, Networking and Intelligent Computing, held in Shenzhen, China. Contributions cover the latest developments and advances in the field of Informatics, Networking and Intelligent Computing.

Download or read book The Structure of Turbulent Shear Flow written by A. A. R. Townsend and published by Cambridge University Press. This book was released on 1976 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt: Develops a physical theory from the mass of experimental results, with revisions to reflect advances of recent years.

Download or read book Experimental and Numerical Investigation of Non isothermal Turbulent Flow Over Wavy Wall written by Liel Barel and published by . This book was released on 2017 with total page 89 pages. Available in PDF, EPUB and Kindle. Book excerpt: