DOCSLIB.ORG

Underwater Acoustics

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Underwater Acoustics Monograph Series in UNDERWATER ACOUSTICS Sponsored by Office of Naval Research Editorial Board: Ralph R. Goodman, Ph.D., Chair Homer P. Bucker, Ph.D. Ira Dyer, Ph.D. Jeffrey A. Simmen, Ph.D. Monograph Series in UNDERWATER ACOUSTICS In 2001 the Office of Naval Research began a program to publish a selected mono- graph series in the field of underwater acoustics. The series publishes in-depth reviews and analysis on the state of understanding of the physics of sound in se- lected areas of research. The monograph series covers the most important topics in underwater sound in an in-depth, critical, scholarly, and comprehensive fashion. It is intended to provide researchers with an understanding of the physics of underwater sound, based on both theory and experiment. The discussion of important unanswered questions is encouraged. Topics of particular importance in the field are low-frequency sound in the deep ocean, shallow-water acoustics, and ambient noise. Sponsored by: Office of Naval Research One Liberty Center 875 North Randolph Street, Suite 1425 Arlington, VA 22203-1995 E-mail: [email protected] Series Editors: Ralph R. Goodman, Ph.D. Homer P. Bucker, Ph.D. Research Professor 808 Moana Drive USM Department of Marine Science San Diego, CA 92106 1020 Balch Blvd E-mail: [email protected] Stennis Space Center, MS 39529 E-mail: [email protected] Ira Dyer, Ph.D. Jeffrey A. Simmen, Ph.D. Weber Shaughness Professor Applied Physics Laboratory of Ocean Engineering, Emeritus University of Washington Massachusetts Institute of Technology 1013 NE 40th Street Cambridge, MA 02139 Seattle, WA 98105-6698 E-mail: [email protected] Charles H. Sherman John L. Butler Transducers and Arrays for Underwater Sound With 388 Illustrations ABC Charles H. Sherman John L. Butler Principal Scientist Chief Scientist Image Acoustics, Inc. Image Acoustics, Inc. 97 Elm Street 97 Elm Street Cohasset, MA 02025 Cohasset, MA 02025 Library of Congress Control Number: 2006921991 ISBN-10: 0-387-32940-4 e-ISBN 0-387-33139-5 ISBN-13: 978-0387-32940-6 Printed on acid-free paper. c 2007 Springer Science+Business Media, LLC All rights reserved. This work may not be translated or copied in whole or in part without the written permission of the publisher (Springer Science+Business Media, LLC, 233 Springer Street, New York, NY 10013, USA), except for brief excerpts in connection with reviews or scholarly analysis. Use in connection with any form of information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed is forbidden. The use in this publication of trade names, trademarks, service marks, and similar terms, even if they are not identified as such, is not to be taken as an expression of opinion as to whether or not they are subject to proprietary rights. 987654321 springer.com To Elizabeth and Nancy Series Preface The efficacy of sound to penetrate the seas made acoustic systems in the past cen- tury the leading tools for sensing objects in and measuring properties of the seas. For over sixty years The United States Office of Naval Research (ONR) has been a major sponsor of undersea research and development at universities, national laboratories, and industrial organizations. Appropriately ONR is the sponsor of this monograph series. The intent of the series is to summarize recent accomplishments in, and to outline perspectives for, underwater acoustics in specific fields of research. The general field has escalated in importance and spread broadly with richness and depth of understanding. It has also, quite naturally, become more specialized. The goal of this series is to present monographs that critically review both past and recent accomplishments in order to address the shortcomings in present under- standing. In this way, these works will bridge the gaps in understanding among the specialists and favorably color the direction of new research and development. Each monograph is intended to be a stand-alone advanced contribution to the field. We trust that the reader will also find that each is a critical introduction to related specialized topics of interest as well. ONR has sponsored the series through grants to the authors. Authors are selected by ONR based on the quality and relevance of each proposal and the author’s experience in the field. The Editorial Board, selected by ONR, has, at times, provided independent views to ONR in this process. Its sole official role, however, is to judge the manuscripts before publication and to assist each author at his request through the process with suggestions and broad encouragement. Ralph R. Goodman, Ph.D. Ira Dyer, Ph.D. Homer P. Bucker, Ph.D. Jeffrey A. Simmen, Ph.D. vii Preface We have written this book as part of the underwater acoustics monograph series initiated by the Office of Naval Research (ONR), Department of the Navy of the United States. The ONR objective for this series is publication of in-depth reviews and analyses of the state of understanding of the physics of sound in selected areas of undersea research. This monograph presents the theory and practice of underwater electroacoustic transducers and arrays as developed during the last half of the twentieth century and into the initial part of the twenty-first century. We have attempted to present a comprehensive coverage of the subject of trans- ducers and arrays for underwater sound starting with a brief historical review and a survey of some of the many modern applications. Descriptions of the six major types of electroacoustic transducers are presented in a unified way that facilitates their comparison and explains why some types are better suited than others for producing and receiving sound in the water. The characteristics of transducers used as both projectors and hydrophones, and the methods available for predict- ing and measuring transducer performance, are presented in detail. The reasons for combining large numbers of transducers in arrays are explained, and the spe- cial problems that must be considered in such arrays are analyzed. The nonlinear mechanisms that exist in all transducers are described, and analyses of some of their most important effects are given. Many different acoustical quantities play essential roles in the design and performance of electroacoustic transducers and arrays, and the methods for determining these quantities are presented. Analyt- ical modeling and understanding is emphasized throughout the book, but it is also made clear that numerical modeling is now an essential part of transducer and array design. Non-electroacoustic types of transducers that are used in certain underwater applications, such as explosive sources, spark sources, hydroacoustic sources, and optical hydrophones, are not included in this book. The monograph is organized in a manner that brings the reader quickly to the main body of results on current transducers and arrays in the first six chapters with a minimum of background material. The most important basic concepts of electroacoustic transduction are introduced in Chapter 1, after a brief historical review and a survey of some of the many applications of transducers and ar- rays. Chapter 2 describes and compares the six major types of electroacoustic ix x Preface transducers, presents additional transducer concepts and characteristics, and intro- duces the equivalent circuit method of transducer analysis. Chapters 3 through 6 contain the main body of results on modern transducers and arrays. Chapters 3 and 4 cover transducers as projectors, which produce sound, and as hydrophones, which receive sound, including many details of specific transducer designs as they are used in current applications. Chapters 5 and 6 explain the benefits of combin- ing large numbers of transducers in arrays that often contain more than a thousand individual transducers. These large arrays are necessary in many sonar applica- tions, but they introduce other problems that are also discussed and analyzed. The remaining six chapters, 7 through 12, support the earlier chapters and carry the discussion of concepts and methods into much more detail for those who seek a deeper understanding of transducer operation. Chapter 7 describes all the princi- pal methods of transducer modeling, analysis, and design, including an introduc- tion to the finite element method. Chapter 8 gives further discussion of the most important transducer characteristics. Chapter 9 describes the principal nonlinear mechanisms that occur in all the transducer types and presents methods of analyz- ing important nonlinear effects such as harmonic distortion. Chapter 10 presents the basic acoustics necessary for determining those acoustical quantities, such as directivity patterns and radiation impedance, that are essential to transducer and array analysis and design. It also includes useful results for such quantities in several typical cases. Chapter 11 extends the discussion of acoustical quantities by introducing more advanced methods of analysis that can be applied to more complicated cases including a brief introduction to numerical methods. Chapter 12 is a summary of the major methods of measurement used for the evaluation of transducer and array performance. The book ends with an extensive Appen- dix containing several types of specific information that can be used in transducer analysis and design and with a Glossary of Terms. We have attempted to make this monograph suitable for beginners to learn from— and for practitioners in the transducer field to learn more from. In addition, those concerned in any way with undersea research may find useful guidance re- garding applications of transducers and arrays. Although some parts of this book may be useful to undergraduates, it is written on a graduate level for engineers and scientists in the fields of electrical engineering, mechanical engineering, physics, ocean engineering, and acoustical engineering. The book uses SI (MKS) units in general, but English units are also occasionally used to clarify the relationship to practical devices.
Load more

Recommended publications
  • Direction-Of-Arrival Estimation Methods in Interferometric Echo Sounding
    sensors Review Direction-of-Arrival Estimation Methods in Interferometric Echo Sounding Piotr Grall * , Iwona Kochanska and Jacek Marszal Faculty of Electronics, Telecommunications and Informatics, Gdansk University of Technology, Narutowicza 11/12, 80-233 Gdansk, Poland; [email protected] (I.K.); [email protected] (J.M.) * Correspondence: [email protected] Received: 24 May 2020; Accepted: 20 June 2020; Published: 23 June 2020 Abstract: Nowadays, there are two leading sea sounding technologies: the multibeam echo sounder and the multiphase echo sounder (also known as phase-difference side scan sonar or bathymetric side scan sonar). Both solutions have their advantages and disadvantages, and they can be perceived as complementary to each other. The article reviews the development of interferometric echo sounding array configurations and the various methods applied to determine the direction-of-arrival. “Interferometric echo sounder” is a broad term, applied to various devices that primarily utilize phase difference measurements to estimate the direction-of-arrival. The article focuses on modifications to the interferometric sonar array that have led to the state-of-the-art multiphase echo sounder. The main algorithms for classical and modern interferometric echo sounder direction-of-arrival estimation are also outlined. The accuracy of direction-of-arrival estimation methods is dependent on the configuration of the array and external and internal noise sources. The main sources of errors, which influence the accuracy of the phase difference measurements, are also briefly characterized. The article ends with a review of the current research into improvements in the accuracy of interferometric echo sounding and the application of the principle of interferometric in other devices.
    [Show full text]
  • The Third Battle
    NAVAL WAR COLLEGE NEWPORT PAPERS 16 The Third Battle Innovation in the U.S. Navy's Silent Cold War Struggle with Soviet Submarines N ES AV T A A L T W S A D R E C T I O N L L U E E G H E T R I VI IBU OR A S CT MARI VI Owen R. Cote, Jr. Associate Director, MIT Security Studies Program The Third Battle Innovation in the U.S. Navy’s Silent Cold War Struggle with Soviet Submarines Owen R. Cote, Jr. Associate Director, MIT Security Studies Program NAVAL WAR COLLEGE Newport, Rhode Island Naval War College The Newport Papers are extended research projects that the Newport, Rhode Island Editor, the Dean of Naval Warfare Studies, and the Center for Naval Warfare Studies President of the Naval War College consider of particular Newport Paper Number Sixteen interest to policy makers, scholars, and analysts. Candidates 2003 for publication are considered by an editorial board under the auspices of the Dean of Naval Warfare Studies. President, Naval War College Rear Admiral Rodney P. Rempt, U.S. Navy Published papers are those approved by the Editor of the Press, the Dean of Naval Warfare Studies, and the President Provost, Naval War College Professor James F. Giblin of the Naval War College. Dean of Naval Warfare Studies The views expressed in The Newport Papers are those of the Professor Alberto R. Coll authors and do not necessarily reflect the opinions of the Naval War College or the Department of the Navy. Naval War College Press Editor: Professor Catherine McArdle Kelleher Correspondence concerning The Newport Papers may be Managing Editor: Pelham G.
    [Show full text]
  • State of the Art in Swath Bathymetry Survey Systems
    International Hydrographie Review, Monaco, LXV(2), July 1988 STATE OF THE ART IN SWATH BATHYMETRY SURVEY SYSTEMS by Christian de MOUSTIER (*) Paper originally presented at the symposium on ‘Current Practices and New Technology in Ocean Engineering’ held by the American Society o/ Mechanical Engineers (ASME) in New Orleans, Louisiana, 10-13 January 1988, and reprinted with the hind authorization of the symposium’s organizers. Abstract In the last decade, advances in real-time computing and data storage capabilities have led to significant improvements in bathymetric survey systems and the single point echo-sounder has now been replaced by a variety of high- resolution swath mapping sounding systems. This paper reviews the state of the art in the non-military swath bathymetry mapping systems. Such systems are typically multi narrow beam echo-sounders or interferometric side-looking sonars with swath width capabilities ranging from 0.75 to 7 times the water depth. The paper compares the design characteristics and the echo processing methods used in a number of these systems manufactured in Japan, Finland, Norway, the U.K., the U.S.A. and West Germany. 1. INTRODUCTION The outcome of a bathymetric survey is a map of water depths in a geographic reference frame. In rivers, estuaries, navigational channels, harbors and in shallow coastal waters, concerns for navigational safety underscore the need for such surveys. In tne open ocean, the incentive for bathymetric surveys is mostly of an exploratory nature, although seamounts are potentially hazardous to submarine navigation. Knowledge of seafloor relief helps marine geologists draw inferences on the dynamic processes that shape the Earth.
    [Show full text]
  • Enabling Shallow-Water Sidescan Sonar Surveys: Using
    Enabling Shallow-Water Sidescan Sonar Surveys: Using Across-Track Beamforming on Receive to Suppress Multipath Interference by Stephen K. Pearce M.A.Sc., Simon Fraser University, 2010 B.S., Washington State University, 2006 a Thesis submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the School of Engineering Science Faculty of Applied Sciences c Stephen K. Pearce 2014 SIMON FRASER UNIVERSITY Summer 2014 All rights reserved. However, in accordance with the Copyright Act of Canada, this work may be reproduced without authorization under the conditions for \Fair Dealing." Therefore, limited reproduction of this work for the purposes of private study, research, criticism, review and news reporting is likely to be in accordance with the law, particularly if cited appropriately. APPROVAL Name: Stephen K. Pearce Degree: Doctor of Philosophy Title of Thesis: Enabling Shallow-Water Sidescan Sonar Surveys: Using Across- Track Beamforming on Receive to Suppress Multipath Inter- ference Examining Committee: Dr. Carlo Menon, Associate Professor Chair Dr. John Bird, Professor, Senior Supervisor Dr. Ivan Bajic, Associate Professor, Supervisor Dr. Paul Ho, Professor, Supervisor Dr. Jie Liang, Associate Professor, Internal Examiner Dr. Jonathan Preston, External Examiner, Adjunct Professor School of Earth and Ocean Sciences University of Victoria Date Approved: June 25, 2014 ii Partial Copyright Licence iii Abstract Sidescan sonars are used to provide a high resolution 2D image of the seafloor, but when used in shallow water these side-looking systems are vulnerable to multipath interference. In some cases, this interference affects image interpretation and downstream processing such as target recognition or bottom classification.
    [Show full text]
  • A CTFM Synthetic Aperture Sonar 101 6.1.1 Projector Radiation Pattern 101 6.1.2 Hydrophone Response 103 X
    CT M s THE C u E Michael P. Hayes, B.E. (Hons) A thesis presented for the degree of Doctor of Philosophy in Electrical and Electronic Engineering, at the University of Canterbury, Christchurch, New Zealand. September 1989. ENGINEERING L1~f\AP-Y iii st Thls thesis describes the theory and operation of a seafloor imaging Synthetic Aper­ ture Sonar (SAS), based on broadband Continuous Tone Frequency Modulation (CTFM). Narrowband synthetic aperture techniques are reviewed, and some of the limita­ tions of using such techniques in sonar applications are described. Aperture under­ sampling is a particular problem when towing single-beam sonars at realistic speeds. However, the mapping rate constraints may be relaxed by using broadband signals, but at the expense of increased self-clutter (or background). One such broadband signal that is suitable for synthetic aperture operation is CTFM. The signal processing requirements for the CTFM signal are investigated, and are shown to be considerably simplified by decomposing each echo sweep into an ensemble of narrowband components. Images reconstructed from each of these components may be combined in a variety of ways. The relative merits of these differing methods are examined using a computer simulation of a side-scan CTFM sonar. The temporal phase stability of the acoustic environment is vital to the formation of a synthetic aperture. An experiment was performed whlch indicates that the phase stability is much better than anticipated, and certainly adequate for the formation of undersea synthetic apertures. Thls prediction was confirmed by another experiment in which the prototype CTFM sonar was moved along a fixed cableway under realistic operating conditions.
    [Show full text]
  • Dynamic Towed Array Models and State Estimation for Underwater Target Tracking
    Calhoun: The NPS Institutional Archive Theses and Dissertations Thesis Collection 2013-09 Dynamic towed array models and state estimation for underwater target tracking Stiles, Zachariah H. Monterey, California: Naval Postgraduate School http://hdl.handle.net/10945/37725 NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS DYNAMIC TOWED ARRAY MODELS AND STATE ESTIMATION FOR UNDERWATER TARGET TRACKING by Zachariah H. Stiles September 2013 Thesis Co-Advisors: Robert G. Hutchins Xiaoping Yun Approved for public release; distribution is unlimited THIS PAGE INTENTIONALLY LEFT BLANK REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188 Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instruction, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302, and to the Office of Management and Budget, Paperwork Reduction Project (0704-0188) Washington DC 20503. 1. AGENCY USE ONLY (Leave blank) 2. REPORT DATE 3. REPORT TYPE AND DATES COVERED September 2013 Master’s Thesis 4. TITLE AND SUBTITLE 5. FUNDING NUMBERS DYNAMIC TOWED ARRAY MODELS AND STATE ESTIMATION FOR UNDERWATER TARGET TRACKING N/A 6. AUTHOR(S) Zachariah H. Stiles 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION Naval Postgraduate School REPORT NUMBER Monterey, CA 93943-5000 9. SPONSORING /MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10.
    [Show full text]
  • Signature Redacted- Hesis Supervisor a Ccep Ted by
    Evaluation by Simulation of an Acoustic Array Composed of Multiple Autonomous Vehicles by Kerry Noonan Bosch6 B.S., United States Naval Academy (2005) M.S., Naval Postgraduate School (2006) Submitted to the Department of Mechanical Engineering in partial fulfillment of the requirements for the degrees of ARCHES0 Naval Engineer MASSACHUSETTS INSTITUTE OF TECHNOLOLGY and 0 Master of Science in Mechanical Engineering JUL 3 2015 at the LIBRARIES MASSACHUSETTS INSTITUTE OF TECHNOLOGY June 2015 @2015 Kerry Noonan Bosch6, All Rights Reserved. The author hereby grants to MIT permission to reproduce and to distribute publicly paper and electronic copies of this thesis document in whole or in part in any medium now known or hereafter created. Author .. Signature redacted.............. Department of Mechanical Engineering -2 May 21, 2015 Certified by......Signature redacted................ Henrik Schmidt Professor Signature redacted- hesis Supervisor A ccep ted by ... .. - - - - - -- - - - ................ David Hardt Chairman, Department Committee on Graduate Students 2 Evaluation by Simulation of an Acoustic Array Composed of Multiple Autonomous Vehicles by Kerry Noonan Bosch6 Submitted to the Department of Mechanical Engineering on May 21, 2015, in partial fulfillment of the requirements for the degrees of Naval Engineer and Master of Science in Mechanical Engineering Abstract Ship-towed arrays have been integral to Navy combatant operations for many decades. The continual advancement of towed array technology has been continually driven by the need for high sensitivity, low self-noise, and response across a wide range of fre- quencies. Robotic autonomy, as applied to acoustic sensors, is currently operationally limited to deployment of traditional arrays from semi-submersible tow vehicles. while such a configuration facilitates flexibility in array placement and a measure of stealth, it is an intermediate step toward fully-submerged, autonomous arrays.
    [Show full text]
  • USCGC Icebreaker Healy (WAGB-20) US Law of the Sea Cruise to Map
    CRUISE REPORT USCGC Icebreaker Healy (WAGB-20) U.S. Law of the Sea cruise to map the foot of the slope and 2500-m isobath of the US Arctic Ocean margin CRUISE HEALY 1102 August 15 to September 28, 2011 Barrow, AK to Dutch Harbor, AK Larry A. Mayer Center for Coastal and Ocean Mapping/Joint Hydrographic Center University of New Hampshire Durham, NH 03824 Andrew A. Armstrong National Oceanic and Atmospheric Administration Joint Hydrographic Center University of New Hampshire Durham, NH 03824 September 28, 2011 HLY1102 Cruise Report Table of Contents Introduction and Background ......................................................................... 3 HEALY-1102 Cruise Overview ................................................................... 16 Scientific Party .............................................................................................. 22 Science Systems Report ................................................................................ 23 Chief Scientist Log ....................................................................................... 66 CTD Log ..................................................................................................... 129 XBT Log ..................................................................................................... 134 APPENDIX A USN METOC Operations Log ........................................... 165 APPENDIX B National Ice Center Report ................................................. 168 APPENDIX C GeoCamera Project ...........................................................
    [Show full text]
  • Methods for Acoustical Analysis of Bat Echolocation and Computational Modeling of Biosonar Signal Processing
    Bio-Inspired Broadband Sonar: Methods for Acoustical Analysis of Bat Echolocation and Computational Modeling of Biosonar Signal Processing By Jason E. Gaudette M.S., University of Rhode Island, May 2005 B.S., Worcester Polytechnic Institute, May 2003 Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Center for Biomedical Engineering at Brown University Providence, Rhode Island May 2014 © Copyright 2014 by Jason E. Gaudette This dissertation by Jason E. Gaudette is accepted in its present form by the Center for Biomedical Engineering as satisfying the dissertation requirement for the degree of Doctor of Philosophy. Date James A. Simmons, Advisor Recommended to the Graduate Council Date Elie L. Bienenstock, Reader Date Rodney J. Clifton, Reader Date Diane Hoffman-Kim, Reader Date Sherief Reda, Reader Date John R. Buck, External Reader Approved by the Graduate Council Date Peter M. Weber, Dean of the Graduate School iii Curriculum Vitae Jason E. Gaudette was born on October 9th, 1980 and raised with his younger sister Renee in Raynham, Massachussets to Edward and Mary Gaudette. Graduating from Bridgewater-Raynham High School in 1999, he continued on to Worcester Polytech- nic Institute to pursue a degree in Electrical Engineering. While an undergraduate Jason studied abroad on three occasions in Madrid, Spain; San Juan, Puerto Rico; and Limerick, Ireland. He received his Bachelor of Science in 2003 with distinction, a concentration in Computer Engineering, and a minor in International Studies. Imme- diately following graduation, Jason began his career at the Naval Undersea Warfare Center in Newport, RI as an Electrical Engineer.
    [Show full text]
  • The Sonar Simulation Toolset, Release 4.6: Science, Mathematics, and Algorithms
    Approved for public release; distribution is unlimited. The Sonar Simulation Toolset, Release 4.6: Science, Mathematics, and Algorithms by Robert P. Goddard Technical Report APL-UW TR 0702 October 2008 Applied Physics Laboratory University of Washington 1013 NE 40th Street Seattle, Washington 98105-6698 ONR Contracts N00014-07-G-0557, N00014-01-G-0460, and N00014-98-G-0001 UNIVERSITY OF WASHINGTON • APPLIED PHYSICS LABORATORY Acknowledgments The Sonar Simulation Toolset was developed with sponsorship from several U.S. Navy sources, most recently ONR Codes 333 (Donald McDowell) and 321US (John Tague and Michael Vaccaro). Earlier sponsors included the Naval Surface Warfare Center, Carderock (William Beatty) and the Naval Underwater Systems Center, New London, CT (Walter Hauck and Thomas Wheeler). The SST development team at APL-UW consists of the author, Bill Kooiman, Keith Wiley, John Pyle, Mike Boyd, and Julia Hsieh. Jim Luby, Warren Fox, and Chris Eggen have provided guidance, testing, and leadership. Earlier team members included Beth Kirby, Kou-Ying Moravan, Pete Brodsky, Brandon Smith, Don Perci- val, Patrick Tewson, Megan Hazen, Gordon Bisset, and undergraduates Pat Lasswell and Jason Smith. Kou-Ying Moravan and Pierre Mourad supplied the original For- tran implementations from which several of the boundary models started. Mike Boyd, Warren Fox, Greg Anderson, and Chris Eggen have contributed CASS expertise. The REVGEN project, where SST got its start, was led by Dave Princehouse. The Comprehensive Acoustic System Simulation (CASS) program is available through the support of the Naval Undersea Warfare Center, Newport (NUWCDI- VNPT). Permission to use and distribute CASS and GSM is granted by NUWC (Emily McCarthy).
    [Show full text]
  • MXP-1(D)(NAVY)(AIR) Multi-National Submarine and Anti-Submarine Exercise Manual
    NATO-UNCLASSIFIED MXP-1(D)(NAVY)(AIR) MXP-1(D)(NAVY)(AIR) MULTI-NATIONAL SUBMARINE AND ANTI-SUBMARINE EXERCISE MANUAL The information contained in this document shall not be released to a nation outside NATO without following procedured contained in C-M(2002)60. 2002 MAY BE CARRIED IN MILITARY AIRCRAFT 1(Reverse Blank) ORIGINAL NATO-UNCLASSIFIED INTENTIONALLY BLANK INTENTIONALLY BLANK NATO-UNCLASSIFIED MXP-1(D)(NAVY)(AIR) RECORD OF RESERVATIONS CHAPTER RECORD OF RESERVATIONS BY NATIONS 1 NONE 2 NONE 3 FRA 4 GBR 5 NONE 6 NONE Non-acceptance of the term “coastal TUR waters” re International Law. V ORIGINAL NATO-UNCLASSIFIED NATO-UNCLASSIFIED MXP-1(D)(NAVY)(AIR) RECORD OF RESERVATIONS (Cont’d) NATION RECORD OF RESERVATIONS BY NATIONS RESERVATIONS FRA During NATO exercises, French SUBOPAUTHs will not approve Relaxation 8 starred NOVEMBER (8*N) and French ships equipped with VDS will receive the order not to stop their sonar while they are trailing their VDS. GBR CASEX S-11. Procedures Para 1b. The purpose of the safety zone is unclear. If it is to provide separation to the OPFOR and FRNFOR submarines when they are both shallow, then 4nm is considered excessive. Suggest the safety area is reduced to 1nm. If it is not for this purpose then clarification should be provided. If the authors of CASEX S-11 or nations are unwilling to amend the safety area dimensions, then GBR should apply a reservation so as to reduce the width to 1nm for GBR use. The reservation is based on the fact that a FRNFOR submarine could potentially be 16nm from an area where it could go shallow or surface.
    [Show full text]
  • Open Nicholaslabarbera.Pdf
    The Pennsylvania State University The Graduate School College of Engineering A COMPARISON OF MODELING APPROACHES OF A HIGH ASPECT CYLINDER IN AXIAL FLOW A Thesis in Engineering Science and Mechanics by Nicholas LaBarbera © 2015 Nicholas LaBarbera Submitted in Partial Fulfillment of the Requirements for the Degree of Master of Science December 2015 The thesis of Nicholas LaBarbera was reviewed and approved∗ by the following: Jonathan S. Pitt Research Associate, Applied Research Laboratory Assistant Professor of Engineering Science and Mechanics Thesis Advisor Robert L. Campbell Research Associate, Applied Research Laboratory Assistant Professor of Mechanical Engineering Judith A. Todd P.B. Breneman Department Chair Department of Engineering Science and Mechanics ∗Signatures are on file in the Graduate School. ii Abstract Simulating a fully-coupled fluid-structure interaction system from first-principles can be very computationally expensive especially for use in design-level analyses; therefore, it is advantageous to explore less computationally expensive methods. By making assumptions about the relevant physics of the problem, simplifications to the governing equations can be applied. These simplifications result in a reduced- order model that can significantly decrease the computational cost; however, the governing equations simplifications result in the reduced-order model neglecting to take into account all the physics of the system. Ideally, the neglected physics would have little to no impact on the dynamics of the system; however, this is not always the case for all input parameters. Therefore, it is important to determine the parameter space for which a reduced order model is valid. In this thesis, numerical simulations of a slender cylinder in axial flow were performed using two different methods.
    [Show full text]