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 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 Modelling and Simulating Unsteady Six Degrees of freedom Submarine Rising Maneuvers written by George Donald Watt and published by . This book was released on 2007 with total page 55 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 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 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 Twenty Third Symposium on Naval Hydrodynamics written by National Research Council and published by National Academies Press. This book was released on 2002-01-01 with total page 1024 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Vive la Revolution!" was the theme of the Twenty-Third Symposium on Naval Hydrodynamics held in Val de Reuil, France, from September 17-22, 2000 as more than 140 experts in ship design, construction, and operation came together to exchange naval research developments. The forum encouraged both formal and informal discussion of presented papers, and the occasion provides an opportunity for direct communication between international peers. This book includes sixty-three papers presented at the symposium which was organized jointly by the Office of Naval Research, the National Research Council (Naval Studies Board), and the Bassin d'Essais des Carènes. This book includes the ten topical areas discussed at the symposium: wave-induced motions and loads, hydrodynamics in ship design, propulsor hydrodynamics and hydroacoustics, CFD validation, viscous ship hydrodynamics, cavitation and bubbly flow, wave hydrodynamics, wake dynamics, shallow water hydrodynamics, and fluid dynamics in the naval context.
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 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 A Collection of the 2004 ASME Wind Energy Symposium Technical Papers at the 42nd AIAA Aerospace Sciences Meeting and Exhibit written by and published by . This book was released on 2004 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mathematical Models and Computer Solution for the Equations of Motion of Surface Ships and Submarines in Six Degrees of Freedom written by Edgardo Juan Romero and published by . This book was released on 1972 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: From the standard equations of motion, mathematical models are developed and standardized for simulation in analog or digital computers. A complete study is done of simulation techniques as applied to the mathematical models. A new technique for simulation of very complex systems of equations including nonlinearities is developed. The model can be used in control studies. Digital simulations of the dynamics of the semisubmerged ship and a submarine in six degrees of freedom are done. This latter with all the nonlinearities and cross-coupling terms included. (Author).
Download or read book 37th AIAA Aerospace Sciences Meeting and Exhibit written by and published by . This book was released on 1999 with total page 714 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NAS Technical Summaries Numerical Aerodynamic Simulation Program March 1990 February 1991 written by and published by . This book was released on 1991 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 29th Plasmadynamics and Lasers Conference written by and published by . This book was released on 1998 with total page 470 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Maschinenbau written by and published by . This book was released on 18?? with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book DTNSRDC Revised Standarrd Submarine Equations of Motion written by and published by . This book was released on 1979 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: Revised standard equations of motion are presented for use in computer simulations of submarine motions in six degrees of freedom conducted for the US Navy. (Author).
Download or read book NAS Numerical Aerodynamic Simulation Program Technical Summaries March 1989 February 1990 written by and published by . This book was released on 1990 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt:
