Laboratory Study of Hydrodynamics of Submerged Brides
Laboratory Study of Hydrodynamics of Submerged Brides

Author: Max Thomson Dean

Publisher:

Published: 2021

Total Pages: 69

ISBN-13:

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Bridges are designed to withstand flood and debris loads; however, it is reported that 53% of bridge failures in the U.S. are caused by hydraulic events, including floods, scour, debris, and drifts. A series of scale flume experiments were conducted to determine flood force effects on bridge superstructures. 1:50 scale models of the Texas Department of Transportation's typical reinforced concrete bridge superstructures were tested. The bridge superstructures included beams (TX28 and TX54 girders, slab beams, and box beams) and an accompanying bridge deck and railing. The drag and lift forces and overturning moments were measured by load sensors for various flow conditions. The experiments were carried out for Froude numbers of 0.2, 0.27, and 0.34 and submergence ratios between 0.25 and 3. The scale model of the superstructure was also tested with debris accumulated on the upstream side of the bridge. Different shapes and amounts of debris were simulated under various flow conditions. The drag, lift, and moment coefficients were calculated and compared to those in literature. The drag coefficients were found to switch from a decreasing to increasing value around an inundation ratio of 0.8 for all superstructure geometries and follow a third-order polynomial distribution. The lift coefficients also followed a similar third-order polynomial distribution pattern with the inflection point at an inundation ratio of 1.0 for the lower Froude number scenario and 0.8 for the high Froude number scenario. The moment coefficients were found to follow logarithmic distribution patterns and to be affected by bridge deck length and superstructure height. The presence of debris increased the observed drag coefficients for a given Froude number. More studies are required to better understand the interaction between the flood flow and bridge structures at the inundation ratios less than one where the inflection points observed on the drag, lift, and moment coefficient graphs. Also, further study of hydrodynamic forces on scale models of a full-bridge structure, including abutments, pier foundation, pier cap, and bearing, and bridge deck system, is recommended.

Fluid Mechanics Experiments
Fluid Mechanics Experiments

Author: Robabeh Jazaei

Publisher: Springer Nature

Published: 2022-05-31

Total Pages: 101

ISBN-13: 303179673X

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Fluid mechanics is one of the most challenging undergraduate courses for engineering students. The fluid mechanics lab facilitates students’ learning in a hands-on environment. The primary objective of this book is to provide a graphical lab manual for the fluid mechanics laboratory. The manual is divided into six chapters to cover the main topics of undergraduate-level fluid mechanics. Chapter 1 begins with an overview of laboratory objectives and the introduction of technical laboratory report content. In Chapter 1, error analysis is discussed by providing examples. In Chapter 2, fluid properties including viscosity, density, temperature, specific weight, and specific gravity are discussed. Chapter 3 revolves around the fluid statics include pressure measurement using piezometers and manometers. Additionally, hydrostatic pressure on the submerged plane and curved surfaces as well as buoyancy and Archimedes’ Principle are examined in Chapter 3. In Chapter 4, several core concepts of fluid dynamics are discussed. This chapter begins with defining a control system based on which momentum analysis of the flow system is explained. The rest of the chapter is allotted to the force acting on a control system, the linear momentum equation, and the energy equation. Chapter 4 also covers the hydraulic grade line and energy grade line experiment. The effect of orifice and changing cross-sectional area by using Bernoulli’s’ equation is presented in Chapter 4. The application of the siphon is extended from Chapter 4 by applying Bernoulli’s’ equation. The last two chapters cover various topics in both internal and external flows which are of great importance in engineering design. Chapter 5 deals with internal flow including Reynolds number, flow classification, flow rate measurement, and velocity profile. The last experiment in Chapter 5 is devoted to a deep understanding of internal flow concepts in a piping system. In this experiment, students learn how to measure minor and major head losses as well as the impact of piping materials on the hydrodynamics behavior of the flow. Finally, open channels, weirs, specific energy, and flow classification, hydraulic jump, and sluice gate experiments are covered in Chapter 6.

Laboratory and Numerical Studies of Hydrodynamics Near Jetties
Laboratory and Numerical Studies of Hydrodynamics Near Jetties

Author:

Publisher:

Published: 2009

Total Pages: 34

ISBN-13:

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Numerical and physical modeling studies were performed by the Coastal Inlets Research Program (CIRP) of the U.S. Army Corps of Engineers to investigate the spatial and temporal behavior of waves and wave-induced currents near jetties of an idealized coastal inlet. Hydrodynamics were examined in the vicinity of two extreme types of jetty structure: a highly absorbing jetty (resembling fairly porous rock rubble structure) and a fully reflective jetty (resembling a vertical sheet pile or caisson type breakwater). Laboratory experiments in a Froude scale of 1:50 were conducted with regular and irregular shore-normal (0 deg) and obliquely incident (20 deg) unidirectional waves. Current and wave measurements were made on the up-wave side and inside the inlet as well as in the bay, along a number of cross-shore and along-shore transects. Wave directions were measured by a remote-sensing video-camera system and Acoustic Doppler Velocimeters (ADV). Numerical modeling was performed with the Coastal Modeling System (CMS) consisting of a two-dimensional circulation model coupled to a spectral wave model. Calculated current and wave fields from CMS in the area around and between absorbing or reflected jetties were compared to measurements. The highly reflecting jetty created a circulation cell on the up-wave side of the inlet, whereas the absorbing jetty did not.

Ocean Energies
Ocean Energies

Author: R.H. Charlier

Publisher: Elsevier

Published: 1993-09-17

Total Pages: 555

ISBN-13: 0080870945

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This timely volume provides a comprehensive review of current technology for all ocean energies. It opens with an analysis of ocean thermal energy conversion (OTEC), with and without the use of an intermediate fluid. The historical and economic background is reviewed, and the geographical areas in which this energy could be utilized are pinpointed. The production of hydrogen as a side product, and environmental consequences of OTEC plants are looked at. The competitiveness of OTEC with conventional sources of energy is analysed. Optimisation, current research and development potential are also examined.Separate chapters provide a detailed examination of other ocean energy sources. The possible harnessing of solar ponds, ocean currents, and power derived from salinity differences is considered. There is a fascinating study of marine winds, and the question of using the ocean tides as a source of energy is examined, focussing on a number of tidal power plant projects, including data gathered from China, Australia, Great Britain, Korea and the USSR.Wave energy extraction has excited recent interest and activity, with a number of experimental pilot plants being built in northern Europe. This topic is discussed at length in view of its greater chance of implementation. Finally, geothermal and biomass energy are considered, and an assessment of their future is given.Each chapter contains bibliographic references. The author has also distinguished between energy schemes which might be valuable in less-industrialized regions of the world, but uneconomical in the developed countries. A large number of illustrations support the text.Every effort has been made to ensure that the book is readable and accessible for the specialist as well as the non-expert. It will be of particular interest to energy economists, engineers, geologists and oceanographers, and to environmentalists and environmental engineers.

Scientific and Technical Aerospace Reports
Scientific and Technical Aerospace Reports

Author:

Publisher:

Published: 1967

Total Pages: 1262

ISBN-13:

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Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

Design in Nature
Design in Nature

Author: Adrian Bejan

Publisher: Anchor

Published: 2013-01-08

Total Pages: 306

ISBN-13: 0307744345

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In this groundbreaking book, Adrian Bejan takes the recurring patterns in nature—trees, tributaries, air passages, neural networks, and lightning bolts—and reveals how a single principle of physics, the constructal law, accounts for the evolution of these and many other designs in our world. Everything—from biological life to inanimate systems—generates shape and structure and evolves in a sequence of ever-improving designs in order to facilitate flow. River basins, cardiovascular systems, and bolts of lightning are very efficient flow systems to move a current—of water, blood, or electricity. Likewise, the more complex architecture of animals evolve to cover greater distance per unit of useful energy, or increase their flow across the land. Such designs also appear in human organizations, like the hierarchical “flowcharts” or reporting structures in corporations and political bodies. All are governed by the same principle, known as the constructal law, and configure and reconfigure themselves over time to flow more efficiently. Written in an easy style that achieves clarity without sacrificing complexity, Design in Nature is a paradigm-shifting book that will fundamentally transform our understanding of the world around us.