Download or read book Drag on Naturally Rippled Beds Under Oscillatory Flows written by Karl E. B. Lofquist and published by . This book was released on 1986 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: Laboratory tests measure the time-dependent drag on naturally rippled sand beds under oscillatory flows. The time integral of the product of this drag and the oscillatory flow velocity provide the energy dissipated per period. A positive kesplacement oscillatory flow tunnel provides amplitudes and periods of flow over a wide range of prototype conditions. With the test section split longitudinally into two channels, one containing the sand bed and the other having a smooth metallic bottom, the drag on the bed is obtained from the measured difference between pressure gradients in the two channels. Two sands are used, with diameters 0.55 and 0.18 mm. The experimental profiles are mostly natural and mature, but some are deliberately distorted. The experimental profiles are in process of growth from a bed initially flat. Bottom stress, including skin friction and profile drag components, is found to be a fairly complicated function of the phase and not proportional to the square of the simultaneous sinusoidal velocity far above the bed. Average values of the bottom stress and rates of energy dissipation are both typically an order of magnitude greater than for a flat surface roughened with fixed grains. Amplitudes and shapes of the curves of stress coefficient as function of phase are interpreted in terms of physical mechanisms and simple models--the profile drag as produced by flow separation at the crest with the growth of an attached vortex in its lee and the skin friction as produced by the flow, modified by a detached vortex, up the ripple face.

Download or read book Calculation of Movable Bed Friction Factors written by Palitha Nalin Wikramanayake and published by . This book was released on 1994 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book NBS Special Publication written by and published by . This book was released on 1980 with total page 964 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modelling and Analysis of Fine Sediment Transport in Wave Current Bottom Boundary Layer written by Liqin Zuo and published by CRC Press. This book was released on 2018-06-19 with total page 193 pages. Available in PDF, EPUB and Kindle. Book excerpt: The evolution and utilization of estuarine and coastal regions are greatly restricted by sediment problems. This thesis aims to better understand fine sediment transport under combined action of waves and currents, especially in the wave-current bottom boundary layer (BBL). Field observations, experimental data analysis, theoretical analysis and numerical models are employed. Silt-dominated sediments are sensitive to flow dynamics and the suspended sediment concentration (SSC) increase rapidly under strong flow dynamics. This research unveils several fundamental aspects of silty sediment, i.e., the criterion of the incipient motion, the SSC profiles and their phase-averaged parameterization in wave-dominated conditions. An expression for sediment incipient motion is proposed for silt-sand sediment under combined wave and current conditions. A process based intra-wave 1DV model for flow-sediment dynamics near the bed is developed in combined wave-current conditions. The high concentration layer (HCL) was simulated and sensitivity analysis was carried out by the 1DV model on factors that impact the SSC in the HCL. Finally, based on the 1DV model, the formulations of the mean SSC profile of silt-sand sediments in wave conditions were proposed. The developed approaches are expected to be applied in engineering practice and further simulation.

Download or read book Coastal Bottom Boundary Layers and Sediment Transport written by Peter Nielsen and published by World Scientific. This book was released on 1992 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is intended as a useful handbook for professionals and researchers in the areas of Physical Oceanography, Marine Geology, Coastal Geomorphology and Coastal Engineering and as a text for graduate students in these fields. With its emphasis on boundary layer flow and basic sediment transport modelling, it is meant to help fill the gap between general hydrodynamic texts and descriptive texts on marine and coastal sedimentary processes. The book commences with a review of coastal bottom boundary layer flows including the boundary layer interaction between waves and steady currents. The concept of eddy viscosity for these flows is discussed in depth because of its relation to sediment diffusivity. The quasi-steady processes of sediment transport over flat beds are discussed. Small scale coastal bedforms and the corresponding hydraulic roughness are described. The motion of suspended sand particles is studied in detail with emphasis on the possible suspension maintaining mechanisms in coastal flows. Sediment pickup functions are provided for unsteady flows. A new combined convection-diffusion model is provided for suspended sediment distributions. Different methods of sediment transport model building are presented together with some classical models.

Download or read book International Compendium of Coastal Engineering written by Shinji E. T. Al SATO and published by World Scientific. This book was released on 2015-04-29 with total page 533 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this book is to provide a comprehensive overview of Coastal Engineering from basic theory to engineering practice. The authors of this book are worldwide authorities in the field. Each chapter deals with an important topic in the field of coastal engineering. The topics are of recent deep concern all over the world motivated by the 2004 Indian Ocean Tsunami, 2005 Hurricane Katrina, 2011 Tohoku Earthquake Tsunami and other natural disasters.For proper coastal zone management, a broad range of knowledge is necessary. This book provides a basic understanding of the theories behind the diverse natural phenomena within the coastal areas, such as waves, tsunamis and sediment transport. The book also introduces various coastal conservation technologies such as coastal structures and beach nourishment. Finally, coastal zone management practices in the USA, Europe, and Japan are introduced.Each chapter is self-standing and readers can begin from any topic depending on their interest.

Download or read book Journal of Research of the National Bureau of Standards written by United States. National Bureau of Standards and published by . This book was released on 1988 with total page 608 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The CERCular written by and published by . This book was released on 1986 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Hydraulic Research in the United States and Canada 1978 written by Pauline H. Gurewitz and published by . This book was released on 1980 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Coastal and Estuarine Processes written by Peter Nielsen and published by World Scientific Publishing Company. This book was released on 2009-04-21 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers water waves, surf zone hydrodynamics, tides in oceans and estuaries, storm surges, estuarine mixing, basic sediment transport, coastal morphodynamics and coastal groundwater dynamics. It is an introductory treatment, suitable for a first course in coastal and estuarine processes for earth scientists or engineers. Yet, there are substantial amounts of new material that are included, such as the explicit, analytical treatment of transient, forced long waves. Inclusion of this material will in turn strongly enhance the introductory treatment of tsunami, storm surges and surf beat. The treatment of sine wave theory emphasizes expressions which are explicit in the water depth h (using koh instead of kh) so that they can easily be differentiated or integrated with respect to h. This is a major pedagogical advantage because of the enhanced transparency. The treatment of turbulent mixing includes finite mixing length effects which provide an explanation for differential diffusion of different sediment sizes in suspension. The effects of acceleration skewness and boundary layer streaming are also included in the basic sediment transport models. The inclusion of beach groundwater dynamics — including the mechanisms by which waves as well as tides drive groundwater motion — provides a link between the previously unconnected fields of coastal hydraulics and regional groundwater modeling. Serving as a good reference book, it is fully indexed and comprehensively cross referenced. Abundant references to more detailed texts are also provided.

Download or read book Hydraulic Research in the United States and Canada written by United States. National Bureau of Standards and published by . This book was released on 1978 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Technical Reports Awareness Circular TRAC written by and published by . This book was released on 1987-04 with total page 620 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Sandy Beach Morphodynamics written by Derek Jackson and published by Elsevier. This book was released on 2020-05-19 with total page 816 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sandy beaches represent some of the most dynamic environments on Earth and examining their morphodynamic behaviour over different temporal and spatial scales is challenging, relying on multidisciplinary approaches and techniques. Sandy Beach Morphodynamics brings together the latest research on beach systems and their morphodynamics and the ways in which they are studied in 29 chapters that review the full spectrum of beach morphodynamics. The chapters are written by leading experts in the field and provide introductory level understanding of physical processes and resulting landforms, along with more advanced discussions. - Includes chapters that are written by the world's leading experts, including the latest up-to-date thinking on a variety of subject areas - Covers state-of-the-art techniques, bringing the reader the latest technologies/methods being used to understand beach systems - Presents a clear-and-concise description of processes and techniques that enables a clear understanding of coastal processes

Download or read book Coastal Engineering 1998 written by Billy L. Edge and published by . This book was released on 1999 with total page 1324 pages. Available in PDF, EPUB and Kindle. Book excerpt: This collection contains more than 270 papers presented at the 26th International Conference on Coastal Engineering, held in Copenhagen, Denmark, June 22-26, 1998.

Download or read book Coastal Engineering 2006 written by Jane McKee Smith and published by . This book was released on 2007 with total page 1114 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book List of Publications of the U S Army Engineer Waterways Experiment Station written by U.S. Army Engineer Waterways Experiment Station and published by . This book was released on 1993 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Publications of the National Institute of Standards and Technology Catalog written by National Institute of Standards and Technology (U.S.) and published by . This book was released on 1983 with total page 442 pages. Available in PDF, EPUB and Kindle. Book excerpt: