Download or read book Unsteady Free Surface Waves Generated by Bodies in a Viscous Fluid written by Dongqiang Lu and published by Open Dissertation Press. This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Unsteady Free-surface Waves Generated by Bodies in a Viscous Fluid" by Dongqiang, Lu, 盧東強, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of thesis entitled UNSTEADY FREE-SURFACE WAVES GENERATED BY BODIES IN A VISCOUS FLUID submitted by Lu Dongqiang for the degree of Doctor of Philosophy at The University of Hong Kong in December 2002 The interaction of laminar flows with free-surface waves generated by submerged bodies in an incompressible viscous fluid of infinite depth is investigated analytically. The analysis is based on the linearized Navier-Stokes equations for disturbed flows. The kinematic and dynamic boundary conditions are linearized for the small-amplitude free-surface waves, and the initial values of the flow are taken to be those of the steady-state cases. The submerged bodies are mathematically represented by fundamental singularities of viscous flows. In the first part of this thesis, the fundamental solutions for the singular Stokes and Oseen flows in an unbounded fluid are derived in a universal form which involves the Hamiltonian, Hessian, and Laplacian operators, and elementary functions. The new solutions for singular unsteady flows can be theoretically applied to construct solutions for general unsteady flows. In the second part, the interaction of unsteady low-Reynolds-number flows with a free surface is investigated analytically. The disturbed flows, generated by submerged bodies moving vertically downwards away from the surface of the fluid, are governed by the unsteady Stokes equations. The submerged body is modeled as a Stokeslet with a vertical component. The asymptotic representations for free-surface waves produced by the instantaneous and oscillating Stokeslets are derived for large time with a fixed distance-to-time ratio. In the third part, the interaction of unsteady far wakes with a free surface is investigated analytically. The disturbed flows generated by submerged bodies moving horizontally beneath the free surface of the fluid are governed by the unsteady Oseen equations. The submerged body is modeled as an Oseenlet with horizontal and vertical components corresponding respectively to the drag and lift exerted on the body. The asymptotic representations are derived for the far-field free-surface waves produced by two-dimensional suddenly starting, suddenly stopping, and oscillating Oseenlets, and by three-dimensional suddenly starting and suddenly stopping Oseenlets. The results obtained show analytically the effects of unsteadiness, viscosity, and submergence on the waves generated. It is found that the unsteady waves generated by a body consist of steady-state and transient responses. As time tends to infinity, the transient waves vanish due to the presence of a viscous decay factor. Thus, an ultimate steady state can be attained. It is demonstrated that the non-physical behavior predicted by the potential-flow theory disappears with the application of the present viscous theory. DOI: 10.5353/th_b2975078 Subjects: Viscous flow Navier-Stokes equations Fluid mechanics Waves

Download or read book Unsteady Free Surface Waves in a Region of Arbitrary Shape written by Ashwini K. Otta and published by . This book was released on 1992 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Calculation of Unsteady Surface Waves written by M. S. Longuet-Higgins and published by . This book was released on 1976 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Directly Multimoded Two flow Long Surface Waves written by Rudolph W. Preisendorfer and published by . This book was released on 1975 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Forcing Long Surface Waves Through Two port Basins written by D. J. Frank and published by . This book was released on 1975 with total page 742 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fluid Dynamics Str mungsmechanik written by C.A. Truesdell and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 822 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sect 2. 317 tinuity surfaces 1. This suggests that a wake pressure Pw be associated with each flow past a bluff body, and that a wake parameter (2. 4) which plays the same role as the cavitation parameter (2. 1), be defined for the flow. This idea has been made the basis of a modified wake theory (ef. Sect. 11) which proves to be in good qu- titative agreement with pressure and drag measurements. It should be emphasized, however, that un h like the cavitation number, the wake parameter is a quantity which is not known a priori, and must be empirically determined in each case. (3) Jet flows. The problem of jet efflux from an orifice is one of the oldest in hydrodynamics and the first to be treated by Fig. 3a. the HELMHOLTZ free streamline theory. Of particular importance for engineering applications is the discharge coefficient Cd' which is defined in terms of the discharge Q per unit time, the pressure P, and the cross-sectional area A of the orifice, by the formula, (2. 5) where e is the fluid density. Two methods of measuring Cd have been most fre quently adopted. In the first the liquid issues from an orifice in a large vessel under the influence of gravity _,-____________ . , (Fig. 3 a), while in the second it 1 L is forced out of a nozzle or pipe under high pressure (Fig. 3 b).

Download or read book Two Methods for the Computation of the Motion of Long Water Waves a Review and Applications written by Robert L. Street and published by . This book was released on 1970 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: The continuing evolution in speed and capacity of digital computers has encouraged the development of many computationally oriented methods for analysis of the movement of waves over the ocean surface and onto the shore. The paper describes two numerical models for the shoaling of water waves where nonlinear effects are significant, but breaking has not occurred. The first model provides an approximate and quasi-three-dimensional simulation (two horizontal space dimensions with vertical effects represented in once integrated equations) of the motion of waves over arbitrary bottom topography. The second model gives an exact simulation of the dynamics of water waves in two-space dimensions. (Author).

Download or read book Proceedings written by Joanna W. Schot and published by . This book was released on 1975 with total page 750 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book On the Nonlinear Evolution of Small Amplitude Free Surface Waves written by Robert David Pierce and published by . This book was released on 1993 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Free Surface Hydraulics written by Dr J M Townson and published by CRC Press. This book was released on 1990-11-22 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: Free-Surface Hydraulics is a unified, pragmatic account of the water surface and its underlying mechanics. Based on the author's 30 years experience of research and teaching in civil engineering hydraulics, this text is designed to help students achieve a coherent understanding More...of a subject often obscured by empirical detail and unstructured approaches. The text leads progressively from hydrostatics, through steady and unsteady flows, to waves and tides. The author draws a careful distinction between kinematic and dynamic motions - the latter he treats at some length by the method of characteristics, regarded as one of the more rigorous approaches to unsteady flow. A special feature is the final chapter, devoted to the disruption of free surfaces by air and bubble motion, especially in pipes.

Download or read book Finite Elements in Water Resources written by K.-P. Holz and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 1095 pages. Available in PDF, EPUB and Kindle. Book excerpt: These proceedings contain the papers presented at the Fourth International Conference on Finite Elements in Water Resources, held in June, 1982, at the University of Hannover, Federal Re public of Germany. This Conference continued the successful series of previous conferences held at Princeton University in 1976, at Imperial College in 1978, and at the University of Mississippi in 1980. Since Finite Elements have proved to be a powerful means for analysing water resource problems, the principal objective of the Conference was to provide an exchange of experiences in practical applications of the finite element method and to establish a forum for discussion regarding accuracy, economy, limitations and improvements. Related discretization methods were included within the scope of the Conference. New develop ments in numerical and computational techniques, basic mathe matical formulations, and soft- and hardware aspects were considered to be equally important topics for an exchange of ideas between both theoretically and practically oriented re searchers. The Conference Organizing Committee is very grateful to the many distinguished scientists who attended the Conference, and for their contributions towards the proceedings. This collection of papers in being made available to a wider audience of en gineers and scientists by CML Publications in Southampton, U.K.

Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1972 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Gravity Waves written by United States. National Bureau of Standards and published by . This book was released on 1952 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Frequency Downshifting in Surface Waves and Free Surface Flows Without Waves written by Ofer Oshri and published by . This book was released on 1996 with total page 474 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Forcing Long Surface Waves Through Two port Basins written by Rudolph W. Preisendorfer and published by . This book was released on 1976 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Numerical Simulation of Water Waves written by Jianhua Tao and published by Springer Nature. This book was released on 2020-03-30 with total page 482 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses the numerical simulation of water waves, which combines mathematical theories and modern techniques of numerical simulation to solve the problems associated with waves in coastal, ocean, and environmental engineering. Bridging the gap between practical mathematics and engineering, the book describes wave mechanics, establishment of mathematical wave models, modern numerical simulation techniques, and applications of numerical models in engineering. It also explores environmental issues related to water waves in coastal regions, such as pollutant and sediment transport, and introduces numerical wave flumes and wave basins. The material is self-contained, with numerous illustrations and tables, and most of the mathematical and engineering concepts are presented or derived in the text. The book is intended for researchers, graduate students and engineers in the fields of hydraulic, coastal, ocean and environmental engineering with a background in fluid mechanics and numerical simulation methods.

Download or read book Twenty Second Symposium on Naval Hydrodynamics written by National Research Council and published by National Academies Press. This book was released on 2000-03-02 with total page 1039 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Twenty-Second Symposium on Naval Hydrodynamics was held in Washington, D.C., from August 9-14, 1998. It coincided with the 100th anniversary of the David Taylor Model Basin. This international symposium was organized jointly by the Office of Naval Research (Mechanics and Energy Conversion S&T Division), the National Research Council (Naval Studies Board), and the Naval Surface Warfare Center, Carderock Division (David Taylor Model Basin). This biennial symposium promotes the technical exchange of naval research developments of common interest to all the countries of the world. The forum encourages both formal and informal discussion of the presented papers, and the occasion provides an opportunity for direct communication between international peers.