Download or read book Numerical Modeling of Ship Motions in Shallow Water Waves written by Hui-shen Chu and published by . This book was released on 1998 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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.
Download or read book Numerical Methods for Seakeeping Problems written by Bettar Ould el Moctar and published by Springer Nature. This book was released on 2021-01-19 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book describes currently applied and newly developed advanced numerical methods for wave-induced ship motions and loads. Besides well-established computational methods based on strip theory, panel methods and finite volume methods for unsteady Reynolds-averaged Navier-Stokes equations (URANS), recent advances like a fully nonlinear Rankine panel method, URANS calculations including elastic hull deformations, and an improved method to predict added resistance in waves are explained in detail. Furthermore, statistical methods to assess extreme motions and loads are described both for linear and nonlinear responses in a stationary seaway as well as during long-term ship operations. Results of motions and loads, computed using the various methods, are compared with each other and with results of model experiments. Introductory chapters on fluid dynamics, motions of rigid and elastic ship hulls, numerical methods to compute fluid flows associated with wind waves, and the development and simulation of seaways complement the volume. The book will be of interest to post-graduate students, PhD candidates, as well as engineers in the field of naval architecture, ocean, and marine engineering.
Download or read book Experiments on ship motions in shallow water written by Armin Walter Troesch and published by . This book was released on 1974 with total page 35 pages. Available in PDF, EPUB and Kindle. Book excerpt: The results of an experimental investigation into shallow water ship motions are presented. The experiments were conducted in two parts. In the first part, the change in form of sinusoidally generated waves as they travel in shallow water were measured. The results are presented as changes in the Fourier harmonics with distance from the wave maker. In the second part, measurements were made of the surge, heave and pitch motions of a tanker model in response to shallow water waves. The waves and motion responses were Fourier analyzed. The experimental results are compared with theoretical predictions made by slender body theory. (Modified author abstract).
Download or read book Numerical Modeling of Water Waves written by Charles L. Mader and published by CRC Press. This book was released on 2004-06-25 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: Numerical Modeling of Water Waves, Second Edition covers all aspects of this subject, from the basic fluid dynamics and the simplest models to the latest and most complex, including the first-ever description of techniques for modeling wave generation by explosions, projectile impacts, asteroids, and impact landslides. The book comes packaged with a CD-ROM that contains the computer codes and movies generated by the author and his colleagues at the Los Alamos National Laboratory. Mader's three-pronged approach--through text, computer programs, and animations--imparts a thorough understanding of new computational methods and provides the tools to put those methods to effective use.
Download or read book Numerical Modeling of Water Waves written by Pengzhi Lin and published by CRC Press. This book was released on 2008-04-30 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modelling large-scale wave fields and their interaction with coastal and offshore structures has become much more feasible over the last two decades with increases in computer speeds. Wave modelling can be viewed as an extension of wave theory, a mature and widely published field, applied to practical engineering through the use of computer tools.
Download or read book Twenty First Symposium on Naval Hydrodynamics written by National Research Council and published by National Academies Press. This book was released on 1997-09-11 with total page 1100 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Wave Ship Interaction in Transforming Seas written by Fuxian Gong and published by . This book was released on 2017 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: In near-shore transforming seas, as waves approach the shoreline, wave shoaling and sometimes wave breaking take place due to the decreasing water depth. When a ship advances through the transforming seas, the ship body and waves interact with each other substantially and can lead to unknown motions of the ship hull. The physical process of how the wave transforms in the surf zone and how the vehicle actually behaves when it passes through the transforming seas is a complicated issue that triggers considerable research interest. The goal of my research is to characterize the dynamics of a high-speed surface ship model in transforming seas through a parametric numerical study of the ship wave interactions. In this study, the vehicle of interest is a surface effect ship (SES) and we aim to contribute to developing a methodology for simulating the transforming wave environment, including wave breaking, and its interactions with the SES. The thesis work uses a commercial software package ANSYS Fluent to generate numerical waves and model the interface between water and air using the volume of fluid (VoF) method. A ship motion solver and the dynamic mesh are used to enable the modeled ship to perform three degree-of-freedom (DoF) motion and the near-region of the ship hull to deform as well as re-mesh. Non-conformal meshes with hybrid compositions of different cell types and various grid sizes are used in the simulations for different purposes. Five user-defined functions (UDFs) are dynamically linked with the flow solver to incorporates ship/grid motions, wave damping and output of the numerical results. A series of steps were taken sequentially: 1) validation for ship motions including simulation of a static Wigley hull under steady flows to compare against previous experimental results by other researchers, and the comparison between the static SES model under steady flows and the moving SES model advancing in the calm water; 2) study of the ship with 3 DoF advancing in calm water of both constant depth and varying depth; 3) validation for numerical waves, including predictions of numerically progressive waves in both a regular tank and a tank with a sloped fringing reef to compare with theoretical and experimental results, respectively; 4) investigation of the transforming characteristics of the wave traveling over the sloped fringing reef, which mimics the near-shore wave environment and a study of the dynamics of the SES through transforming waves. We find that the flow solver used in this study reliably models the wave profiles along the ship hull. The comparison between a static SES in a current and a moving SES in calm water at the same Froude number shows that although the velocity fields around the vehicle are significantly different, the wave profiles inside and outside the rigid cushion of the vehicle are similar and the resistance force experienced by the vehicle in the two scenarios agree well over time. We conducted five numerical simulations of the vehicle traveling from shallow water to deep water across the transition zone for different Froude numbers. From the results, we find that as the Froude number increases, the wave resistance force on the vehicle becomes larger in both shallow water and deep water. In addition, the overall mean resistance force experienced by the vehicle over the whole trip increases with the Froude number. Statistical analysis of the wave motions suggests that the energy flux decreases dramatically in the onshore direction as the waves break. The more severe the wave-breaking process, the greater the decrease in energy flux. Both the increase of Froude number and the wave steepness apparently increase the resistance force on the vehicle in the shallow water. This thesis work captures the impact of the transforming characteristics of the waves and closely replicates the behavior of how waves interact with a ship in transforming seas through numerical modeling and simulation.
Download or read book Numerical Simulation of Nonlinear Waves and Ship Motions written by John R. (John Robert) Fitz-Clarke and published by . This book was released on 1986 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ship Motions and Drag Reduction written by Johannes Krzywinski Lunde and published by . This book was released on 1966 with total page 1182 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 1976 with total page 838 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Twenty Fourth Symposium on Naval Hydrodynamics written by National Research Council and published by National Academies Press. This book was released on 2003-11-15 with total page 1018 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report is part of a series of reports that summarize this regular event. The report discusses research developments in ship design, construction, and operation in a forum that encouraged both formal and informal discussion of presented papers.
Download or read book Time domain Simulation of Wave induced Ship Motions by a Rankine Panel Method written by Junshi Wang and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, a numerical program has been developed to simulate the wave-induced ship motions in the time domain. Wave-body interactions have been studied for various ships and floating bodies through forced motion and free motion simulations in a wide range of wave frequencies. A three-dimensional Rankine panel method is applied to solve the boundary value problem for the wave-body interactions. The velocity potentials and normal velocities on the boundaries are obtained in the time domain by solving the mixed boundary integral equations in relation to the source and dipole distributions. The hydrodynamic forces are calculated by the integration of the instantaneous hydrodynamic pressures over the body surface. The equations of ship motion are solved simultaneously with the boundary value problem for each time step. The wave elevation is computed by applying the linear free surface conditions. A numerical damping zone is adopted to absorb the outgoing waves in order to satisfy the radiation condition for the truncated free surface. A numerical filter is applied on the free surface for the smoothing of the wave elevation. Good convergence has been reached for both forced motion simulations and free motion simulations. The computed added-mass and damping coefficients, wave exciting forces, and motion responses for ships and floating bodies are in good agreement with the numerical results from other programs and experimental data.
Download or read book Numerical Simulation of Large Amplitude Ship Motions written by Shukui Liu and published by LAP Lambert Academic Publishing. This book was released on 2012-04 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: The reliable prediction of the seakeeping behavior of ships in real seas is a demanding task for naval architects and of great interest to ship owners/operators, as it affects both the design and operation of ships. In this work, a set of methods, namely, a time domain transient Green function solver, alternatively a time domain hybrid solver for zero speed problems and the adopted hybrid solver for nonzero forward speed problem, are developed to study the seakeeping behavior of ships and floating structures in waves. Validation cases cover both simple mathematical geometries and practical ship hulls, either without or with forward speed. Obtained results include radiation/diffraction forces, wave making resistance, motion simulation and added resistance (drift force). It is proved that by properly selecting a solver the developed package is capable of simulating large amplitude motions of ships or floating structures in waves thus it can serve as an advanced tool for the assessment of ship design and operation. This work is expected to offer researchers in similar field a state of art review of the problem and certain amount of inspiration in terms of numerical implementation.
Download or read book Ship Motions written by B. V. Korvin-Kroukovsky and published by . This book was released on 1959 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tracings: 98.40.
Download or read book Selected Papers from the Sixth International Symposium on Marine Propulsors written by Sverre Steen and published by MDPI. This book was released on 2020-12-29 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt: Marine propulsors are key components of the many thousands of ships and boats operating in oceans, lakes, and rivers around the world. The performance of propulsors are important for the environmental impact of ships, underwater noise impact on aquatic fauna, and crew and passenger comfort and safety. This book presents nineteen papers devoted to the hydrodynamics of different types of marine propulsors (conventional propellers, thrusters, and novel solutions). Most of the papers are extended papers from the sixth International Symposium on Marine Propulsors (SMP 2019). Several of the papers deal with cavitation, vortices, and energy saving devices. The papers present high-quality research performed using Computational Fluid Dynamics (CFD) and Experimental Fluid Dynamics (EFD) as well Artificial Intelligence (AI).
Download or read book Time domain Analysis of Ship Motions and Hydrodynamic Pressures on a Ship Hull in Waves written by and published by . This book was released on 1998 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper describes the development of a three-dimensional time-domain numerical model for calculating hull pressures as well for as hydroelastic analysis of a ship hull in waves. In this work, hydrodynamic forces & pressures due to radiated & diffracted waves are expressed as convolution products of a response function with either the velocity of ship motion or the wave elevation. The method significantly reduces the need for numerical evaluation of the time-domain Green function in the convolution of memory effects. The response functions of forces & pressures of radiated & diffracted waves are obtained by numerically solving the Fredholm integral equation of the first kind. In the equations of motion, maneuvering & rudder forces, radiation & diffraction forces, and non-linear restoring & Froude-Krylov forces are taken into account. Numerical examples are presented to compare computed & measured results.
