Wave Propagation in Viscoelastic and Poroelastic Continua

Author: Martin Schanz

Publisher: Springer Science & Business Media

ISBN: 9783540416326

Category: Technology & Engineering

Page: 184

View: 5079

Wave propagation is an important topic in engineering sciences, especially, in the field of solid mechanics. A description of wave propagation phenomena is given by Graff [98]: The effect of a sharply applied, localized disturbance in a medium soon transmits or 'spreads' to other parts of the medium. These effects are familiar to everyone, e.g., transmission of sound in air, the spreading of ripples on a pond of water, or the transmission of radio waves. From all wave types in nature, here, attention is focused only on waves in solids. Thus, solely mechanical disturbances in contrast to electro-magnetic or acoustic disturbances are considered. of waves - the compression wave similar to the In solids, there are two types pressure wave in fluids and, additionally, the shear wave. Due to continual reflec tions at boundaries and propagation of waves in bounded solids after some time a steady state is reached. Depending on the influence of the inertia terms, this state is governed by a static or dynamic equilibrium in frequency domain. However, if the rate of onset of the load is high compared to the time needed to reach this steady state, wave propagation phenomena have to be considered.

Wave and Tidal Energy

Author: Deborah Greaves,Gregorio Iglesias

Publisher: John Wiley & Sons

ISBN: 111901445X

Category: Science

Page: 720

View: 9080

A comprehensive text covering all aspects of wave and tidal energy Wave and Tidal Energy provides a comprehensive and self-contained review of the developing marine renewable energy sector, drawing from the latest research and from the experience of device testing. The book has a twofold objective: to provide an overview of wave and tidal energy suitable for newcomers to the field and to serve as a reference text for advanced study and practice. Including detail on key issues such as resource characterisation, wave and tidal technology, power systems, numerical and physical modelling, environmental impact and policy. The book also includes an up-to-date review of developments worldwide and case studies of selected projects. Key features: A comprehensive and self-contained text covering all aspects of the multidisciplinary fields of wave and tidal energy. Draws upon the latest research in wave and tidal energy and the experience of leading practitioners in numerical and laboratory modelling. Regional developments worldwide are reviewed and representative projects are presented as case studies. Wave and Tidal Energy is an invaluable resource to a wide range of readers, from engineering students to technical managers and policymakers to postgraduate students and researchers.

Water Wave Scattering

Author: Birendra Nath Mandal,Soumen De

Publisher: CRC Press

ISBN: 1498705537

Category: Mathematics

Page: 376

View: 2707

The theory of water waves is most varied and is a fascinating topic. It includes a wide range of natural phenomena in oceans, rivers, and lakes. It is mostly concerned with elucidation of some general aspects of wave motion including the prediction of behaviour of waves in the presence of obstacles of some special configurations that are of interest to ocean engineers. Unfortunately, even the apparently simple problems appear to be difficult to tackle mathematically unless some simplified assumptions are made. Fortunately, one can assume water to be an incompressible, in viscid and homogeneous fluid. The linearised theory of water waves is based on the assumption that the amplitude of the motion is small compared to the wave length. If rotational motion is assumed, then the linearised theory of water waves is essentially concerned with solving the Laplace equation in the water region together with linearised boundary condition. There are varied classes of problems that have been/are being studied mathematically in the literature within the framework of linearised theory of water waves for last many years. Scattering by obstacles of various geometrical configurations is one such class of water wave problems. This book is devoted to advanced mathematical work related to water wave scattering. Emphasis is laid on the mathematical and computational techniques required to study these problems mathematically. The book contains nine chapters. The first chapter is introductory in nature. It includes the basic equations of linearised theory for a single layer fluid, a two-layer fluid, solution of dispersion equations, and a general idea on scattering problems and the energy identity in water with a free surface. Chapter 2 is concerned with wave scattering involving thin rigid plates of various geometrical configurations, namely, plane vertical barriers or curved barriers, inclined barriers, horizontal barrier, and also thin elastic vertical plate. For the horizontal case, the barrier is submerged below an ice-cover modelled as a thin elastic plate floating on water. Chapter 3 discusses wave scattering by a rectangular trench by using Galerkin technique. Chapter 4 involves wave scattering by a dock by using Carleman singular integral equation followed by reduction to Riemann-Hilbert problems. Chapter 5 involves several wave scattering problems involving discontinuities at the upper surface of water by using the Wiener-Hopf technique, by reduction to Carleman singular integral equations. Chapter 6 considers scattering by a long horizontal circular cylinder either half immersed or completely submerged. In chapter 7, some important energy identities are derived for scattering problems in a single-layer and also in a two-layer fluid. Chapter 8 is concerned with wave scattering in a two-layer fluid by a thin vertical plate and by a long horizontal circular cylinder submerged in either of the two layers. Chapter 9 is the final chapter which considers a number of wave scattering problems in a single-layer or a two-layer fluid with variable bottom topography by using a simplified perturbation analysis It is hoped that this book will be useful to researchers on water waves. The several wave scattering problems presented in the book are mostly based on the research work carried out by the authors and their associates.

Reeds Introductions: Physics Wave Concepts for Marine Engineering Applications

Author: Christopher Lavers

Publisher: Bloomsbury Publishing

ISBN: 1472922166

Category: Technology & Engineering

Page: 224

View: 4258

Reeds Introductions: Physics Wave Concepts for Marine Engineering Applications covers the fundamental theoretical maritime physics concepts which underpin electromagnetic wave and sonar principles as developed in most maritime-related courses, whether Naval, Coastguard or Merchant Marine engineering. For these reasons it is vital that maritime users have a basic understanding of the concepts upon which many essential modern sea-going sensors and communications devices now operate. Knowledge regarding electromagnetic waves and electromagnetic devices is an established merchant navy sea service requirement, particularly for the Standards in Training and Certification in Watchkeeping (STCW95) qualification in various Maritime Coastguard Agency exams, e.g. Marine Electrotechnology (as Chief Engineer and Second Engineer), as mandated by the UK Department for Transport. This short introductory book is written as simply as possible to support growing numbers of overseas students for whom English is not their first language. This volume provides a comprehensive study of maritime physics principles and provides a firm foundation prior to reading and studying of the following Reeds Marine Engineering series: Vols 1, 3, 6, 7, 14 and 15. Students having read this easy-to-read volume will be better prepared for the more in depth study of the other volumes listed.

Millimeter-Wave Gyrotron Traveling-Wave Tube Amplifiers

Author: Chao-Hai Du,Pu-Kun Liu

Publisher: Springer

ISBN: 3642547281

Category: Technology & Engineering

Page: 192

View: 3147

A gyrotron traveling-wave amplifier (gyro-TWT) with the high-power and broad-band capabilities is considered as a turn-on key for next generation high-resolution radar. The book presents the most advanced theory, methods and physics in a gyro-TWT. The most challenging problem of instability competition has been for the first time addressed in a focused and systematic way and reported via concise states and vivid pictures. The book is likely to meet the interest of researchers and engineers in radar and microwave technology, who would like to study the gyro-TWTs and to promote its application in millimeter-wave radars. Chao-Hai Du and Pu-Kun Liu are both professors at Peking University.

Harmonic Wave Systems: Partial Differential Equations of the Helmholtz Decomposition

Author: Victor A. Miroshnikov

Publisher: Scientific Research Publishing, Inc. USA

ISBN: 1618964062

Category: Science

Page: 460

View: 6877

Harmonic Wave Systems is the first textbook about the computational method of Decomposition in Invariant Structures (DIS) that generalizes the analytical methods of separation of variables, undetermined coefficients, asymptotic expansions, and series expansions. In recent years, there has been a boom in publications on propagation of nonlinear waves described by a fascinating list of partial differential equations (PDEs). The vast majority of wave problems are reducible to one-dimensional ones in propagation variables. However, a list of publications with two- and three-dimensional applications of the DIS method is brief. The book offers a comprehensive and rigorous treatment of the DIS method in two and three dimensions using the PDE approach to the Helmholtz decomposition that provides the most general background for mathematical modelling of harmonic waves in fluid dynamics, electrodynamics, heat transfer, and other numerous areas of science and engineering, which are dealing with propagation and interaction of N internal waves.