Download or read book Modelling and Simulation of High Speed Supercavitating Vehicle written by Santosh Burnwal and published by LAP Lambert Academic Publishing. This book was released on 2012-04 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: Supercavitation is an emerging technology in which the most cursed 'Cavitation' is used as a beneficial to engineering application. Supercavitation is achieved when a body moves through water at sufficiently high speed, so that the fluid pressure drops to the water vapour pressure and a vapour bubble (called cavity) envelops the entire vehicle (except the cavitator and fins). Hence, the skin friction drag of the vehicle becomes almost zero. Hence, vehicle can move in the two phase medium.The development of supercavitating vehicle has been confronted with various challenging problems such as the potential instability of the vehicle, the unsteady nature of the cavity dynamics and the complex, non-linear and time delayed nature of the interaction between vehicle and cavity. Moreover depending upon some non dimensional parameter e.g. cavitation number ( ), the equilibrium of the vehicle may shift from a stable equilibrium to a limit cycle."

Download or read book Modeling Dynamics and Control of High speed Supercavitating Vehicles written by Anand K. Jammulamadaka and published by . This book was released on 2002 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Numerical Modeling of Supercavitating Flows written by I. N. Kirschner and published by . This book was released on 2001 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt: Supercavitating bodies can achieve very high speeds under water by virtue of reduced drag: with proper design, a cavitation bubble is generated at the nose and skin friction drag is drastically reduced. Depending on the type of supercavitating vehicle under consideration, the overall drag coefficient can be an order of magnitude less than that of a fully wetted vehicle. Slender-body theory and boundary element methods are two modern computational methods applied to the design of supercavitating vehicles. These course notes present recent advances in the theory behind these two computational approaches, as well as results and application of the methods to the simulation and control of supercavitating vehicles.

Download or read book An Integrated Approach to the Design of Supercavitating Underwater Vehicles electronic Resource written by Seong Sik Ahn and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A supercavitating vehicle, a next-generation underwater vehicle capable of changing the paradigm of modern marine warfare, exploits supercavitation as a means to reduce drag and achieve extremely high submerged speeds. In supercavitating flows, a low-density gaseous cavity entirely envelops the vehicle and as a result the vehicle is in contact with liquid water only at its nose and partially over the afterbody. Hence, the vehicle experiences a substantially reduced skin drag and can achieve much higher speed than conventional vehicles. The development of a controllable and maneuvering supercavitating vehicle has been confronted with various challenging problems such as the potential instability of the vehicle, the unsteady nature of cavity dynamics, the complex and non-linear nature of the interaction between vehicle and cavity. Furthermore, major questions still need to be resolved regarding the basic configuration of the vehicle itself, including its control surfaces, the control system, and the cavity dynamics. In order to answer these fundamental questions, together with many similar ones, this dissertation develops an integrated simulation-based design tool to optimize the vehicle configuration subjected to operational design requirements, while predicting the complex coupled behavior of the vehicle for each design configuration. Particularly, this research attempts to include maneuvering flight as well as various operating trim conditions directly in the vehicle configurational optimization. This integrated approach provides significant improvement in performance in the preliminary design phase and indicates that trade-offs between various performance indexes are required due to their conflicting requirements. This dissertation also investigates trim conditions and dynamic characteristics of supercavitating vehicles through a full 6 DOF model. The influence of operating conditions, and cavity models and their memory effects on trim is analyzed and discussed. Unique characteristics are identified, e.g. the cavity memory effects introduce a favorable stabilizing effect by providing restoring fins and planing forces. Furthermore, this research investigates the flight envelope of a supercavitating vehicle, which is significantly different from that of a conventional vehicle due to different hydrodynamic coefficients as well as unique operational conditions.

Download or read book Advancement and Application of Multiphase CFD Modeling to High Speed Supercavitating Flows written by and published by . This book was released on 2004 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent progress in the development and application of homogenous multiphase CFD methods for large-scale gas cavities in liquid flows are presented. The focus of the presentation is on work in n-species transport approaches applied to developed and super-cavitation. Numerical formulation, physical modeling, and applications are included. Numerical issues to be discussed include: preconditioning in the context of incompressible through supersonic Mach numbers, arbitrary numbers of species, high density ratios, and large gas volume/mass fractions; computational grid requirements; dual-time formulation; and general large-scale high-performance computing. Physical modeling issues to be discussed include: homogeneous mixture compressibility; mass-transfer modeling; condensable and non-condensable gas species; turbulence modeling; and 6-degree-of-freedom 6DOF flowfield/rigid-body interaction. The applications to be presented range from naturally cavitating modeled flow on simple configurations (ogives, nozzles, airfoils/wedges) to more industrially relevant, complex-geometry applications including turbomachinery (cavitation breakdown), and super-cavitation (underwater rockets, hypervelocity darts, condensable and non-condensable cavities, gas-on/off transients, twin-vortex regime). Recent applications including Detached Eddy Simulation DES of natural cavities, and 6DOF analysis of a propelled notional super-cavitating vehicle are presented.

Download or read book Supercavitation written by Igor Nesteruk and published by Springer Science & Business Media. This book was released on 2012-01-13 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: This collection is dedicated to the 70th jubilee of Yu. N. Savchenko, and presents experimental, theoretical, and numerical investigations written by an international group of well-known authors. The contributions solve very important problems of the high-speed hydrodynamics,such as supersonic motion in water, drag diminishing, dynamics and stability of supercavitating vehicles, water entry and hydrodynamic performances of hydrofoils, ventilated cavities after a disc and under the ship bottom. The book is written for researches, scientists, engineers, and students interested in problems of hydromechanics.

Download or read book Abhandlung der historischen Frage wie weit die R mischen Waffen in Teutschland gekommen written by and published by . This book was released on 17?? with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Model and Control Validation of a High Speed Supercavitating Vehicle written by David Escobar Sanabria and published by . This book was released on 2012 with total page 113 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Supercavitation written by Igor Nesteruk and published by Springer Science & Business Media. This book was released on 2012-01-11 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: This collection is dedicated to the 70th jubilee of Yu. N. Savchenko, and presents experimental, theoretical, and numerical investigations written by an international group of well-known authors. The contributions solve very important problems of the high-speed hydrodynamics,such as supersonic motion in water, drag diminishing, dynamics and stability of supercavitating vehicles, water entry and hydrodynamic performances of hydrofoils, ventilated cavities after a disc and under the ship bottom. The book is written for researches, scientists, engineers, and students interested in problems of hydromechanics.

Download or read book Numerical Simulation of Ultra high Speed Supercavitating Flows Considering the Effects of the Water Compressibility written by and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Mechatronics and Automatic Control Systems written by Wego Wang and published by Springer Science & Business Media. This book was released on 2013-11-18 with total page 1041 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book examines mechatronics and automatic control systems. The book covers important emerging topics in signal processing, control theory, sensors, mechanic manufacturing systems and automation. The book presents papers from the 2013 International Conference on Mechatronics and Automatic Control Systems in Hangzhou, held in China during August 10-11, 2013.

Download or read book Commerce Business Daily written by and published by . This book was released on 1998-05 with total page 1902 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Basic Research Into High Speed Supercavitating Bodies written by and published by . This book was released on 2001 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: Critical technologies related to SCAT development, including cavitator hydrodynamics, control surface hydrodynamics, static pressure sensing, flow noise calculations and hydrodynamics modeling of high-speed supercavitating flows. Focused on critical technologies related to SCAT development, including hydrodynamics of advanced cavitator concepts, control surface hydrodynamics, cavity geometry studies for comparisoin with CFD modeling, small-scale model design and fabrication, and flow noise testing and modeling.

Download or read book Autonomous Underwater Vehicles written by Sabiha Wadoo and published by CRC Press. This book was released on 2017-12-19 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: Underwater vehicles present some difficult and very particular control system design problems. These are often the result of nonlinear dynamics and uncertain models, as well as the presence of sometimes unforeseeable environmental disturbances that are difficult to measure or estimate. Autonomous Underwater Vehicles: Modeling, Control Design, and Simulation outlines a novel approach to help readers develop models to simulate feedback controllers for motion planning and design. The book combines useful information on both kinematic and dynamic nonlinear feedback control models, providing simulation results and other essential information, giving readers a truly unique and all-encompassing new perspective on design. Includes MATLAB® Simulations to Illustrate Concepts and Enhance Understanding Starting with an introductory overview, the book offers examples of underwater vehicle construction, exploring kinematic fundamentals, problem formulation, and controllability, among other key topics. Particularly valuable to researchers is the book’s detailed coverage of mathematical analysis as it applies to controllability, motion planning, feedback, modeling, and other concepts involved in nonlinear control design. Throughout, the authors reinforce the implicit goal in underwater vehicle design—to stabilize and make the vehicle follow a trajectory precisely. Fundamentally nonlinear in nature, the dynamics of AUVs present a difficult control system design problem which cannot be easily accommodated by traditional linear design methodologies. The results presented here can be extended to obtain advanced control strategies and design schemes not only for autonomous underwater vehicles but also for other similar problems in the area of nonlinear control.

Download or read book Hydrodynamics of Free boundary Flows written by Georgiĭ Vladimirovich Logvinovich and published by . This book was released on 1972 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book An Assessment of Undersea Weapons Science and Technology written by National Research Council and published by National Academies Press. This book was released on 2000-07-09 with total page 71 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Department of the Navy strives to maintain, through its Office of Naval Research (ONR), a vigorous science and technology (S&T) program in those areas considered critically important to U.S. naval superiority in the maritime environment, including littoral waters and shore regions. In pursuing its S&T investments in such areas, ONR must ensure that (1) a robust U.S. research capability to work on long-term S&T problems in areas of interest to the Department of the Navy and the Department of Defense is sustained, (2) an adequate supply of new scientists and engineers in these areas is maintained, and (3) S&T products and processes necessary to ensure future superiority in naval warfare are provided. One of the critical areas for the Department of the Navy is undersea weapons. An Assessment of Undersea Weapons Science and Technology assesses the health of the existing Navy program in undersea weapons, evaluates the Navy's research effort to develop the capabilities needed for future undersea weapons, identifies non-Navy-sponsored research and development efforts that might facilitate the development of such advanced weapons capabilities, and makes recommendations to focus the Navy's research program so that it can meet future needs.

Download or read book Cavitation and Bubble Dynamics written by Christopher E. Brennen and published by Cambridge University Press. This book was released on 2014 with total page 269 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cavitation and Bubble Dynamics deals with fundamental physical processes of bubble dynamics and cavitation for graduate students and researchers.