Download or read book Predicting the Transient Hydrodynamic Loads on Submarine Hulls in Unsteady Maneuvers written by Robert Andrew Doyle and published by . This book was released on 2020 with total page 349 pages. Available in PDF, EPUB and Kindle. Book excerpt: Submarine maneuvering analysis requires accurate and computationally efficient methods to predict the hydrodynamic loading on a vehicle. During maneuvers in a viscous fluid, this loading will have unsteady contributions from both the added mass of the surrounding fluid, and from motion history effects due to the shedding of vorticity into the wake. Despite this, the majority of models for submarine hydrodynamics assume quasi-steady loading, which neglects the motion history effect. This assumption is primarily made due to our limited understanding of unsteady submarine hydrodynamics. This work presents an analysis of the flow around unappended, maneuvering submarine hulls. This was accomplished using Computational Fluid Dynamics simulations of the flow around the hull. These simulations were validated by comparison against experimental data for an Unmanned Underwater Vehicle of similar geometry to a submarine hull. A range of maneuvers were simulated to explore the effect of unsteady motion. These maneuvers were restricted to planar motions without rotation, and included steady translations, impulsive accelerations, sustained accelerations, and sinusoidally oscillating maneuvers. The hulls studied range in slenderness from 7.5

Download or read book Hydrodynamic Loads on Axisymmetric Bodies with Casings in Translation written by Cory Robert Marshall and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive study was performed of hydrodynamic forces and moments on submarine hull geometries with casings in steady translation using an enhanced database consisting of experimental and computational results. The objective was to develop a hydrodynamic load estimation method that allows for the rapid simulation of the performance characteristics of underwater vehicles. This is an important step in determining the safe operating envelope of submarines. Accurate potential flow and viscous flow results of the geometries of interest were performed at varying incidence and orientation angles. The simulations were verified by a mesh refinement study and validated against analytical solutions and experimental data. Potential flow was found to be a useful predictor of the effects of geometric asymmetric on the out-of-plane and in-plane force distributions and moments. The viscous simulations showed that casings, and hull asymmetries in general, have significant effects on the separation lines, surface pressure distributions, and wake topologies. These effects caused large variations in the in-plane loads and introduced out-of-plane loads. Increasing the casing width produced the largest changes in the in-plane and out-of-plane loads and wake topology. Previous models were found to be unsuitable for the prediction of the in-plane loads on hulls with casings mainly due to their reliance on slender body theory. An alternative model was developed, which combined potential flow with viscous contributions to obtain the hydrodynamic impulse. The tail plane impulse, and therefore the hydrodynamic force, could be approximated with the first nine Fourier modes of the orientation angle. The hydrodynamic moment predictions were found to be accurate. The model was found to have difficulty in predicting the in-plane moment for small asymmetries such as a narrow casing.

Download or read book Practical Ship Hydrodynamics written by Volker Bertram and published by Elsevier. This book was released on 2012 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt: Practical Ship Hydrodynamics provides a comprehensive overview of hydrodynamic experimental and numerical methods for ship resistance and propulsion, maneuvering, seakeeping and vibration. Beginning with an overview of problems and approaches, including the basics of modeling and full scale testing, expert author Volker Bertram introduces the marine applications of computational fluid dynamics and boundary element methods. Expanded and updated, this new edition includes: Otherwise disparate information on the factors affecting ship hydrodynamics, combined to provide one practical, go-to resource. Full coverage of new developments in computational methods and model testing techniques relating to marine design and development. New chapters on hydrodynamic aspects of ship vibrations and hydrodynamic options for fuel efficiency, and increased coverage of simple design estimates of hydrodynamic quantities such as resistance and wake fraction. With a strong focus on essential background for real-life modeling, this book is an ideal reference for practicing naval architects and graduate students.

Download or read book Estimating the In plane Hydrodynamic Loads on a Submarine Hull at Incidence written by Michael Mackay and published by . This book was released on 2006 with total page 77 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Unsteady Computational Fluid Dynamics Simulations of Six Degrees of freedom Submarine Manoeuvres written by Mark Bettle and published by . This book was released on 2013 with total page 211 pages. Available in PDF, EPUB and Kindle. Book excerpt: Submarine hydrodynamicists are continually striving to improve submarine manoeuvring predictions in order to better understand operational limitations. Traditional manoeuvring simulations use semi-empirical force estimation methods or captive model experiments to predict hydrodynamic forces and moments on the manoeuvring submarine. Semi-empirical methods are inexpensive and fast but not consistently accurate. Coefficient-based models derived from captive model experiments are more accurate but much more expensive. Time-history effects are also difficult to incorporate in coefficient-based modelling and are thus often neglected. The effect of the seabed and other passing vessels are also not included in traditional models. In order to address these issues, an unsteady, six degrees-of-freedom (DOF), Reynolds Averaged Navier-Stokes (RANS) submarine simulation approach has been developed and applied to simulating the emergency rising manoeuvre and the interaction between a submarine and a passing tanker. In this method, the 6 DOF motion of the full-scale submarine is integrated simultaneously with the RANS solution for fluid forces. Coefficient-based modelling is used for the propeller, control-surface deflections, and ballast blowing in order to achieve economical solutions while accounting for the important viscous effects. The submarine motion is integrated implicitly using a robust predictor-corrector approach that uses a novel application of semiempirical and coefficient-based models to accelerate convergence at each timestep. A combination of sliding interfaces and mesh deformation is used to account for the relative motion between the tanker and submarine. Simulation results reproduce the roll-instability observed for buoyantly rising submarines and provide insight on the magnitude of the disturbance forces and submarine motions induced by a large tanker passing over a diesel-electric submarine.

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 Hydrodynamics and Maneuvering Simulations of a Non body of revolution Submarine written by John E. Poremba and published by . This book was released on 2009 with total page 103 pages. Available in PDF, EPUB and Kindle. Book excerpt: Historically, physics-based predictions of the hydrodynamics and the rigid-body dynamics (six-degree-of-freedom trajectory, velocities and accelerations) associated with a maneuvering submarine is a challenging task. This is due to the tightly coupled nature of the fluid mechanics and dynamics of the vehicle, and the magnitude of the computational problem associated with resolving the hull, moving appendages, and propulsors. However, successful development and validation of a computational approach for simulating submarine maneuvering is important for understanding routine and emergency operations, and it can be used as part of the toolset in establishing a safe-operating envelope and for design and analysis of future undersea vehicles. In this research, the hydrodynamics and motions for a maneuvering submarine with a non-body-of-revolution hull form and X-stern control appendages are studied. The tightly coupled unsteady Reynolds averaged Navier-Stokes and six-degree-of-freedom (REL-TCURS) simulation tool, developed at the Applied Research Laboratory at Penn State, is used to perform time-accurate calculations for a series of basic maneuvers such as turning circles. For computational efficiency, REL-TCURS replaces control appendages and propulsors with body-force models, and it is shown that these models can be calibrated with fidelity models of the actual control appendages. The computational fluid dynamics model is validated through comparisons with force and moment data from steady wind tunnel experiment. The REL-TCURS simulations are compared to free-running model test data. While there is discrepancy in certain details of the rigid-body dynamics, which are attributed to uncertainty in the initial conditions and the vehicle mass properties, the REL-TCURS simulations resolve roll instability seen in the model, and are able to definitively link the instability to a sail/control appendage interaction. This result demonstrates the utility and importance of being able to correlate time-accurate hydrodynamics, with control surface and propulsor commands, and with resultant vehicle dynamics.

Download or read book Analytical Calculations of Fatigue Loading of Submarine Hulls written by Ian Miles Robertson and published by . This book was released on 1990 with total page 75 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1978 with total page 1018 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Submarine Hydrodynamics written by Martin Renilson and published by Springer. This book was released on 2015-03-10 with total page 163 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book adopts a practical approach and presents recent research together with applications in real submarine design and operation. Topics covered include hydrostatics, manoeuvring, resistance and propulsion of submarines. The author briefly reviews basic concepts in ship hydrodynamics and goes on to show how they are applied to submarines, including a look at the use of physical model experiments. The issues associated with manoeuvring in both the horizontal and vertical planes are explained, and readers will discover suggested criteria for stability, along with rudder and hydroplane effectiveness. The book includes a section on appendage design which includes information on sail design, different arrangements of bow planes and alternative stern configurations. Other themes explored in this book include hydro-acoustic performance, the components of resistance and the effect of hull shape. Readers will value the author’s applied experience as well as the empirical expressions that are presented for use at the preliminary design stage. A wide range of state-of-the-art material is included, and there are over fifty references to recent publications in the field. Intended for advanced students and professionals working in the specialised field of submarine hydrodynamics, this book brings theoretical and practical knowledge together in one comprehensive work that is particularly valuable to the submarine hydrodynamicist.

Download or read book Marine Hydrodynamics 40th anniversary edition written by J. N. Newman and published by MIT Press. This book was released on 2018-01-26 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt: A textbook that offers a unified treatment of the applications of hydrodynamics to marine problems. The applications of hydrodynamics to naval architecture and marine engineering expanded dramatically in the 1960s and 1970s. This classic textbook, originally published in 1977, filled the need for a single volume on the applications of hydrodynamics to marine problems. The book is solidly based on fundamentals, but it also guides the student to an understanding of engineering applications through its consideration of realistic configurations. The book takes a balanced approach between theory and empirics, providing the necessary theoretical background for an intelligent evaluation and application of empirical procedures. It also serves as an introduction to more specialized research methods. It unifies the seemingly diverse problems of marine hydrodynamics by examining them not as separate problems but as related applications of the general field of hydrodynamics. The book evolved from a first-year graduate course in MIT's Department of Ocean Engineering. A knowledge of advanced calculus is assumed. Students will find a previous introductory course in fluid dynamics helpful, but the book presents the necessary fundamentals in a self-contained manner. The 40th anniversary of this pioneering book offers a foreword by John Grue. Contents Model Testing • The Motion of a Viscous Fluid • The Motion of an Ideal Fluid • Lifting Surfaces • Waves and Wave Effects • Hydrodynamics of Slender Bodies

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 U S Government Research Development Reports written by and published by . This book was released on 1967-07 with total page 766 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Maritime Engineering Reference Book written by Anthony F. Molland and published by Elsevier. This book was released on 2011-10-13 with total page 921 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Maritime Engineering Reference Book is a one-stop source for engineers involved in marine engineering and naval architecture. In this essential reference, Anthony F. Molland has brought together the work of a number of the world's leading writers in the field to create an inclusive volume for a wide audience of marine engineers, naval architects and those involved in marine operations, insurance and other related fields. Coverage ranges from the basics to more advanced topics in ship design, construction and operation. All the key areas are covered, including ship flotation and stability, ship structures, propulsion, seakeeping and maneuvering. The marine environment and maritime safety are explored as well as new technologies, such as computer aided ship design and remotely operated vehicles (ROVs).Facts, figures and data from world-leading experts makes this an invaluable ready-reference for those involved in the field of maritime engineering.Professor A.F. Molland, BSc, MSc, PhD, CEng, FRINA. is Emeritus Professor of Ship Design at the University of Southampton, UK. He has lectured ship design and operation for many years. He has carried out extensive research and published widely on ship design and various aspects of ship hydrodynamics.* A comprehensive overview from best-selling authors including Bryan Barrass, Rawson and Tupper, and David Eyres* Covers basic and advanced material on marine engineering and Naval Architecture topics* Have key facts, figures and data to hand in one complete reference book

Download or read book Government Reports Announcements written by and published by . This book was released on 1967 with total page 1182 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1988 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: