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Twenty-Second Symposium on Naval Hydrodynamics Twenty-Second Symposium on NAVAL HYDRODYNAMICS Opening Remarks
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Twenty-Second Symposium on Naval Hydrodynamics Dr. Fred E.Saalfeld Deputy Chief of Naval Research/Technical Director Ladies and gentlemen, welcome to the Twenty-Second Symposium on Naval Hydrodynamics. I hope that our participants from across the United States and from abroad have had time over the past couple of days to enjoy some of the sights in our nation’s capital. First-time visitors will find that there is plenty to see and do, and visitors who have already been here are well aware that Washington is a city to be rediscovered over and over. The technical program for this symposium is outstanding. A reading of the titles of the papers suggests excitement in the naval hydrodynamics community. Frequently used terms such as “fully nonlinear,” “unstructured grids,” “verification,” and “validation” indicate the extent to which naval hydrodynamics has pushed back frontiers. The papers in this symposium document the state of the art for ship hydrodynamics. Once again the symposium on naval hydrodynamics has asserted its international importance by providing a technical forum and, through the published proceedings, archival documentation of progress in the field. This symposium is a biennial event that began in 1956. It is an international conference dedicated to the archiving and dissemination of the state of the art in naval hydrodynamics, and in particular ship hydrodynamics. The organizing committee consists of representatives from the United States, Europe, and the Far East. The location for the symposium rotates through these three geographical regions. This year the symposium is sponsored by the Office of Naval Research, the National Research Council, and the Naval Surface Warfare Center, Carderock Division. Our official host is the Naval Surface Warfare Center. This institution has undergone many name changes over the years, and most of you know it by the name, David Taylor Model Basin. David Taylor Model Basin, known internationally as DTMB, has a prestigious history and is now celebrating its centennial. Last night at the opening reception in the Washington Navy yard you had the opportunity to visit the Experimental Model Basin, the forerunner of the current facilities at Carderock, just outside Washington, and where you will be touring on Wednesday afternoon. When you visit the facilities at David Taylor Model Basin, I would like you to keep in mind that naval hydrodynamics is undergoing a revolution in the way that ship hydrodynamics are predicted and evaluated. I am using the word “revolution” cautiously. In the world of ship hydrodynamics nothing changes very fast; hence any notable change could be classified as a revolution. And that revolution is the incorporation of computational methods, using the world’s largest supercomputers, to complement and greatly expand the utility of the towing tank. Traditionally, naval hydrodynamicists have relied on small ship models (around 20 feet in length) pulled by large moving vehicles of sorts in a long basin of water, the towing tank. You will see these at David Taylor Model Basin. Measurements using the models are used to predict the performance of actual full-scale ships. The advent of super-computers has promised an alternative way to obtain data, namely by numerically solving the equations for the hydrodynamics using supercomputers. The practical result is that the research community is rapidly approaching the state in which the computations can be benchmarked, or calibrated, with highly accurate towing tank measurements. The computer can then be efficiently used to greatly expand the database and to extrapolate the model-scale information to the full-scale case. The procedures to do this are only now being formulated and tested. In this symposium you will hear from researchers whose papers describe the application of computational methods, the analysis of experimental and numerical uncertainty, and the results of new measurement techniques necessary to produce the highly accurate towing tank calibrations. I am pleased to note that the symposium ends with sessions dedicated to this process, and I look forward to the next symposium, at which I expect to see numerous papers implementing complementary experimental and computational techniques. In the United States there is a movement toward implementing computational ship hydrodynamics for preliminary design of naval ships at the shipyards. It is necessary that the science and technology community, represented by this symposium, produce verified and validated software so that computers can be optimally utilized in the initial design and evaluation of ships. This week you are fortunate to be able to hear several distinguished lectures by international experts. These plenary sessions are featured each morning and will set the pace for the papers to be
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Twenty-Second Symposium on Naval Hydrodynamics presented through the remainder of each day. The lecture on Wednesday morning is the Weinblum Lecture, which is an annual event jointly sponsored by the United States and Germany. And, for the first time, there will be a poster session, which is scheduled for Thursday afternoon. At this session participants will be able to interact directly and personally with the presenters as they describe their results. I should also mention the social activities that surround this symposium, which started with the excellent reception at the Navy yard yesterday evening. I also know that numerous technical committees are meeting around the symposium schedule, such as International Towing Tank Conference committees and Society of Naval Architects and Marine Engineers panels. All of these activities, including presentations of more than 60 papers and the involvement of more than 200 participants, promise to produce a memorable Twenty-Second Symposium on Naval Hydrodynamics. I wish you a stimulating meeting. Thank you.
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Twenty-Second Symposium on Naval Hydrodynamics CAPT John Preisel, USN Commanding Officer Naval Surface Warfare Center, Carderock Division Ladies and gentlemen, it is my great pleasure to welcome you to the Twenty-Second Symposium on Naval Hydrodynamics. I am CAPT John Preisel, and Dick Metrey and I are here to represent the host organization, the Carderock Division of the Naval Surface Warfare Center, or the David Taylor Model Basin, as many of you know it. We are especially honored to be hosts because this is the centennial year of the U.S. Navy’s Experimental Model Basin, the forerunner of the David Taylor Model Basin. Admiral David Taylor, a young naval constructor, built the U.S. Navy’s first towing tank 100 years ago at the Navy yard directly across from the Navy Museum where we had the reception last evening. The building is still there. You may have noticed it. That towing tank was built to serve the U.S. Navy and the maritime industry and address hydrodynamic problems. One hundred years later the Navy is still addressing hydrodynamic problems, and the problems are still attracting worldwide interest. This symposium continues the wonderful tradition of the exchange of naval hydrodynamics research. This tradition was started 42 years ago in this very building at the First Symposium on Naval Hydrodynamics. That symposium honored CAPT Harold E.Saunders, USN, for his work in constructing the David Taylor Model Basin and the high standards he set for research in naval hydrodynamics. As the commanding officer of the Carderock Division, I am concerned with the progress of a broad range of science and technology areas. Hydrodynamics is a core technology for the Carderock Division. It is core because we are a ships platform laboratory, not a weapons or communications laboratory. Our large hydrodynamic facilities are a major investment by the Navy and the nation. The Navy recognizes hydrodynamics as a core technology because fundamentally the U.S. Navy is about ships at sea. It is essential because crucial problems in hydrodynamics exist to this day. Your papers and discussions are proof that progress is being made. But no one would say that all fundamental areas have been closed and the final textbook is ready to be written. The Navy and other major institutions around the world are facing tremendous pressure to reduce costs. I see signs that the reduction is cutting into the science and technology base, namely our basic and applied research programs. This is happening when more sophisticated physical testing is required to validate CFD codes and design methods. On top of this there is the continuing problem of maintaining facilities. Some of them are beginning to show their age. Another concern is that we, as a scientific community, have an aging and retiring work force. We are facing a significant loss of senior people in the next 5 to 10 years. Look around you this morning and note the graying heads. I was surprised and disappointed to learn that there are only nine students registered for this symposium. I extend a special welcome to these students and hope that they use this opportunity to make contacts with the giants in their field of specialization. I hope to have an opportunity to meet each of them. In the future, I would like to see sponsoring organizations explore ways to help more students attend these symposia. Part of our job is to inspire young people to join our profession. In honor of the centennial we have completed a history of the Carderock and Annapolis laboratories. The centennial gave us a chance to look back and put the current issues that are facing us in perspective. It is interesting to note that the Navy and our laboratory have faced similar problems before. We serve as the steward of the technology essential to a viable Navy both today and in the future. Stewardship requires that we be willing to team with organizations worldwide to mutually contribute strength. Stewardship requires that we keep proficient in core technical areas such as hydrodynamics. Stewardship requires that we continually evaluate technologies and replace them with better technologies. Stewardship sometimes means keeping an important Navy technology, even when commercial and academic interest is gone. We know that in this day and age, no one can go it alone with such a demanding task. We must work closely with one another, and this is the importance of symposia such as this. I believe that it is most appropriate that we host this symposium on our centennial. I extend a warm welcome to you on this symposium opening and also hope to see you during the tour and the picnic this Wednesday at our Carderock base and at the banquet on Thursday evening. I hope that you participate in the activities to the fullest extent possible, both technically and socially. The result will be a week that is both stimulating and rewarding.
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Twenty-Second Symposium on Naval Hydrodynamics VADM Albert J.Baciocco, Jr., USN (retired) Naval Studies Board Good morning. I am very pleased to be here—and very pleased to see that the agenda for the Twenty-Second Symposium on Naval Hydrodynamics continues to fulfill the founding objective set for this forum in 1956, “…to provide an international forum for the exchange of ideas and research results in the field of ship hydrodynamics.” I would like to offer just a few comments, hopefully of some value, from my perspective as a former Chief of Naval Research (1978–1981, during the time of the 12th and 13th symposia); as the former Director of Navy RDT&E (OP-098) (1983–1987, during the time of the 15th and 16th symposia); as a former naval person for some 11 years now, a period during which, in 1996, I had the privilege of serving as chair of a milestone independent study for the Department of the Navy Secretariat which scrutinized and assessed the technology base for our newest attack submarine design, the NSSN; and today as a current member of the Naval Studies Board. Throughout my naval career as a submarine officer, and in my assignments with the science and technology community, I have maintained a continuing strong interest in naval hydrodynamics, in the funding that was allocated to this important technical discipline, and in the expectations for technical results to be achieved and then applied from these sustained efforts. I was therefore somewhat stunned when my 1996 submarine technology assessment study found that the Navy’s technology base in ship hydrodynamics (for submarines at least, arguably with the possible exception of the propulsor area) was weak if not non-existent, lacking support, and virtually bereft of bold, forward-looking research initiatives. (Other areas were found to be weak as well, but they are not the subject of this symposium.) There was little support for the few remaining outstanding hydrodynamics researchers within the Navy, and thus little incentive for bright new researchers to come on board. This vital technical area was not being viewed as an important continuum. There was no evidence of a focused, continuing, and long-term programmatic commitment to R&D investment and to results in this area so critical to our Navy’s submarines (and I think I could safely state that the situation differed little in the surface ship area). Happily, as a result of this study, a commitment to increased and sustained funding for submarine research and development, and especially for hydrodynamics, was made by the Department of the Navy and strongly supported by the Congress. Funding was, at least initially, increased measurably, even in the face of a severely constrained defense budget. Today, that commitment to hydrodynamics, indeed to science and technology funding overall, while still espoused by many, appears to have waned somewhat as overall Department of the Navy resources continue to be reduced relative to current-day operational needs. A bleak outlook for R&D, S&T,…and indeed for hydrodynamics! How could this happen? What to do? Some thoughts…. I noted some written comments from a credible participant in the recent international symposium on seawater drag reduction (technically a younger cousin of this forum) conducted just last month at the Naval Undersea Warfare Center in Newport, Rhode Island. The comments related a summary historical overview of past and general assessment of current work, and included the following excerpt, “…work continues at a low level, mostly in the European community, Japan, and the former Soviet Union. The lack of practical results has eroded support for drag reduction research. The community does not yet have a firm grasp on the underlying physical phenomena. Recent advances in experimental and numerical methods may lead to a fundamental understanding if sufficiently supported.” Could it be that this comment holds a clue to the reason that all aspects of naval hydrodynamics, including those to be discussed in this forum, are not being supported as strongly as those of us in this audience feel it should? Think about it. Think about it in the context of the current research funding environment where, increasingly, greater portions of the R&D enterprise are becoming requirements driven, and near-term, useful results are demanded. Inexplicably, less tolerance is afforded the idea of research efforts, i.e., advancing the frontier of scientific knowledge. Increasingly, we note examples where even the most dedicated research manager is forced to predict the timing and application of research results, to have objectives that meet current requirements, that fit the business plan. Not true research, many say, but apparently the model that more and more programs are being forced to follow. Maybe, if one believes the quoted sound bite from that “other symposium,” the current environment is, in part, the product of past performance by
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Twenty-Second Symposium on Naval Hydrodynamics the naval hydrodynamics community itself. Consider the following: What is fundamentally different in today’s agenda from that material presented at this symposium during the 1960s? the 1970s? the 1980s? Why has hydrodynamics not advanced like other disciplines, such as materials and information technology? Certainly the excellence of the principal investigators and the community is there. And there is no lack of interest or need either in the military or in the commercial maritime world, where transportation costs are an important factor in the international market. Where are the enduring proven concepts for advanced warships and for improved ship types such as high-speed interoceanic military (fast sealift) and commercial transports (a “maritime fedex”?)? Review of this symposium’s agenda indicates a look at important parts of such challenges, but a more systematic approach to the hydrodynamic issues of such challenges is not clearly evident. While specific technical topics of scientific interest and accomplishment are covered, there is only scant evidence of relationships between technologies, or the contribution of one discipline to a system of disciplines. In my view, it is time for the hydrodynamics community to recognize and to acknowledge the need and embrace a more multi- and interdisciplinary approach to their investigations. It is time for the community to consider hydrodynamics in the full context of the systems in which this vital science plays. Take a true systems approach. Make hydrodynamics research clearly a more cost-effective investment—with efforts directed at combinations of technologies, where the synergy of otherwise marginal returns of individual technologies may significantly improve the end product, and consider including efforts with the ship design engineer, the physical chemist, the biologist, the molecular physicist,…and don’t forget the objective futurist. The hydrodynamics community has a responsibility to educate and knowledgeably articulate the ultimate benefits of their science. For example, in a military scenario, the application of improved hydrodynamics to reduce submarine flow noise attacks the problem at its source and perhaps has the potential to radically reduce the cost of sonar signal processing. Traditional solutions would generally work only to enhance listening capability, but a hydrodynamic solution could provide a cumulative benefit in that the mechanisms that reduce the energy expended to create the flow noise also reduce the power required to propel the platform. This, in turn, serves to reduce the inherent self-noise and signature generated by the platform. You, the community, need to demonstrate that the smart application of hydrodynamics can provide more complete and cost-effective solutions to such multifaceted, complex problems. As you go forward with the agenda of this symposium, I ask you to ponder what I have suggested. I am strongly in favor of continuing healthy support for basic and applied research, especially in hydrodynamics, and for the objective of advancing the frontiers of scientific knowledge. However, I firmly believe that the community needs to recognize the vagaries of today’s environment and embrace a bit more vigorously the need to recognize and to practice the “systems engineering” aspects of their science and to seek to embark on a few bold, multidisciplinary efforts that have the clear potential to reward the maritime customers of the world with opportunities for early applications of truly innovative and paradigm-shifting technologies. As you of the hydrodynamics community set sail into the new millennium, let me offer a few points of wise guidance and encouragement, appropriately nautical, to guide your voyage into a challenging and exciting future: Set your sights high—be bold—pick a star to steer by; Always heed and respect the power and beauty of Mother Nature; Give any rocks and shoals you may encounter a wide berth; and, ’Though the seas, at times, be rough, maintain a firm grip on the helm, a steady course—and fear not! To all of you, then—good luck, every success, and bon voyage! I have appreciated the opportunity to share these few moments with you this morning, and I wish your symposium great success. Thank you.
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Representative terms from entire chapter: