Air cushion vehicles (ACVs) have operated successfully on commercial routes for about twenty years. The routes are normally quite short; the craft are equipped with radar and radio navigation aids and maintain continu...
详细信息
Air cushion vehicles (ACVs) have operated successfully on commercial routes for about twenty years. The routes are normally quite short; the craft are equipped with radar and radio navigation aids and maintain continuous contact with their terminals. Navigation of these craft, therefore, does not present any unusual difficulty. The introduction of air cushion vehicles into military service, however, can present a very different picture, especially when external navigation aids are not available and the craft must navigate by dead reckoning. This paper considers the problems involved when navigating a high-speed air cushion vehicle by dead reckoning in conditions of poor visibility. A method is presented to assess the ACV's navigational capability under these circumstances. A figure of merit is used to determine the sensitivity of factors which affect navigation such as the range of visibility, point-to-point distance, speed, turning radius and accuracy of onboard equipment. The method provides simplistic but adequate answers and can be used effectively to compare the-capability and cost of alternative navigation concepts.
A two-dimensional kinetic theory analysis is used to determine distribution functions in high-temperature mirror plasmas in which both Coulomb and nuclear elastic scattering are important. The discrete nature of nucle...
A two-dimensional kinetic theory analysis is used to determine distribution functions in high-temperature mirror plasmas in which both Coulomb and nuclear elastic scattering are important. The discrete nature of nuclear scattering and the continuous nature of Coulomb scattering are incorporated. The distribution functions are used to obtain the energy deposition and energy and particle loss rates for fusion reaction products such as alpha particles and protons in the central-cell plasma of a tandem mirror. The confinement time for neutral-beam-injected ions in the plug of a tandem mirror or in a single-cell mirror is also determined. Large-angle scattering losses are found to depend more strongly on mirror ratio than losses due to small-angle scattering, although including the motion of background ions reduces the effects of nuclear scattering. For d-t reactor parameters, the effects of nuclear scattering are not significant. For d-d reactors, however, the confinement time for 700 keV plug neutral beams is found to decrease by 20%.
作者:
BAITIS, AEAPPLEBEE, TRMCNAMARA, TMA. Erich Baitis:
a native of Germany came to the David W. Taylor Naval Ship R&D Center in 1957 as a cooperative student/trainee and received his B.S. degree in physics from Virginia Polytechnic Institute. As a 32-year-old naval architect in 1971 he received both the Vietnam Honor Service Medal and the Navy's Meritorious Civilian Service Award for his eight months as liaison with the Vietnamese Navy's ferro-cement program. As head of the Seakeeping and Stabilization Group of the Surface Ship Dynamics Branch his work has led to the development of a new standard Ship Motion Computer Program and the application of ship motions to ship habitability operability and survivability problems. A major area of this work has been the ship-aircraft interface which is particularly sensitive to ship motions wind and other environmental factors. He is a member of the American Society of Naval Engineers and was awarded the Solberg Award for 1982 “in recognition of significant engineering research and development contributions in the area of improved helicopter operations from a ship in a seaway.” Terrence A. Applebee:is currently a naval architect at the David W. Taylor Naval Ship R&D Center in the Surface Ship Dynamics Branch. he came to the Center after earning a B.S. degree in ocean engineering from Florida Institute of Technology in 1973. Since that time
he has worked in the areas of seakeeping performance evaluation ship-helicopter interfacing and human factor considerations. He is a member of the American Society of Naval Engineers and the Society of Naval Architects and Marine Engineers. Thomas M. McNamara:is an employee of the John Hopkins University Applied Physics Laboratory in the ocean data acquisition program. From 1979 to 1983
he worked at David W. Taylor Naval Ship R&D Center in the Surface Ship Dynamics Branch. His expertise has focused on the development of computer models for human factor evaluations as well as motion stabilization systems. He has participated in the development of advanced stabilizat
The FFG 7/LAMPS MK III Operator Guidance Manual (OGM) was developed for all FFG-7 class frigates which are not fin stabilized or are operating with the fins off. The OGM was developed to assis the ship operators of th...
The FFG 7/LAMPS MK III Operator Guidance Manual (OGM) was developed for all FFG-7 class frigates which are not fin stabilized or are operating with the fins off. The OGM was developed to assis the ship operators of the FFG-7 class in choosing ship speed and heading combinations which will minimize ship motion-related problems during various phases of the LAMPS deployment. Crew safety and performance were major concerns in the development of the OGM. This paper reviews the effect of human factors on ship operations during helicopter recovery, maintenance, and transit to and from the hangar.
作者:
PAIGE, KKCONVERSE, RAUSNLCdr. Kathleen K. Paige
USN:graduated with a BA from the University of New Hampshire in 1970. She received her commission from Officer Candidate School in April 1971 and performed her first tour of duty with VFP-63 NAS Miramar. LCdr. Paige then received her MS from the Naval Post Graduate School in June 1976 and returned to San Diego to serve as Head Support Software Division at the Fleet Combat Direction System Support Activity. In May 1981 she reported to NA VSEA (PMS-408) where she served initially as Chairman of the NAVMAT Software Engineering Environment Working Group. She has been assigned as Deputy AN/UYK-43 Acquisition Manager since October 1981. LCdr. Paige was designated a fully qualified Engineering Duty Officer in December 1983. Robert A. Converse:is presently the Acquisition Manager for the Ada Language System/Navy (ALS/N) for the Naval Sea Systems Command Tactical Embedded Computer Resources Project. As such
he is responsible for the definition and development of the ALS/N to be provided as a Navy standard computer programming system for Navy mission critical applications. Mr. Converse received a Bachelor of Science degree in Physics from Wheaton College Wheaton II. He spent fourteen years with the Naval Underwater Systems Center Newport Rhode Island during which time he designed and developed the Fortran compiler for the Navy Standard AN/UYK-7 computer. Also during that period he received a Master of Science degree in Computer Science from the University of Rhode Island. His thesis for that degree was entitled “Optimization Techniques for the NUSC Fortran Cross-Compiler”. Mr. Converse started his involvement with the Ada program in 1975 with the initial “Strawman” requirements review. Subsequently he was named as the Navy Ada Distinguished Reviewer and was intimately involved in the selection and refinement of the Ada language as it evolved to become ANSI/MIL-STD-1815A.
The U.S. Navy introduced the use of digital computers in mission critical applications over a quarter of a century ago. Today, virtually every system in the current and planned Navy inventory makes extensive use of co...
The U.S. Navy introduced the use of digital computers in mission critical applications over a quarter of a century ago. Today, virtually every system in the current and planned Navy inventory makes extensive use of computer technology. computers embedded in mission critical Navy systems are integral to our strategic and tactical defense capabilities. Thus, the military power of the U.S. Navy is inextricably tied to the use of programmable digital computers. The computerprogram is the essential element that embodies the system “intelligence”. In addition, it provides the flexibility to respond to changing threats and requirements. However, this very flexibility and capability poses a host of difficulties hindering full realization of the advantages. This paper describes the lessons learned about computerprogram development over the past twenty five years and discusses a software engineering process that addresses these lessons. It then describes how Ada and its related Ada programming Support and Run-Time Environments foster this software engineering process to improve computerprogram productivity and achieve greater system reliability and adaptibility. Finally, the paper discusses how the use of Ada and its environments can enhance the interoperability and transferability of computerprograms among Navy projects and significantly reduce overall life cycle costs for Navy mission critical computerprograms.
A ship design methodology is presented for developing hull forms that attain improved performance in both seakeeping and resistance. Contrary to traditional practice, the methodology starts with developing a seakeepin...
A ship design methodology is presented for developing hull forms that attain improved performance in both seakeeping and resistance. Contrary to traditional practice, the methodology starts with developing a seakeeping-optimized hull form without making concessions to other performance considerations, such as resistance. The seakeeping-optimized hull is then modified to improve other performance characteristics without degrading the seakeeping. Presented is a point-design example produced by this methodology. Merits of the methodology and the point design are assessed on the basis of theoretical calculations and model experiments. This methodology is an integral part of the Hull Form Design System (HFDS) being developed for computer-supported naval ship design. The modularized character of HFDS and its application to hull form development are discussed.
In this experiment, the charge state distribution resulting from atomic rearrangement following the creation of the inner shell vacancies in krypton atoms has been recorded. Intense, highly collimated, monochromatic a...
详细信息
In this experiment, the charge state distribution resulting from atomic rearrangement following the creation of the inner shell vacancies in krypton atoms has been recorded. Intense, highly collimated, monochromatic and tunable X-ray radiation available at the CHESS synchrotron radiation facility at Cornell was used to photionize krypton atoms in a gas jet target, and a time-of-flight spectrometer was used to record the ions in different charge states formed after photoionization. Charge state spectra were recorded below, at the 'peak' in the K edge and above the edge. Below the edge, charge states plus 4 to plus 7 were observed with appreciable intensity, while at, and above the edge, the charge states ranged from plus 4 to plus 10.
The objective of the program reported in this paper was to assess the explosion and fire hazard associated with the crude-oil offloading facility proposed for the Deep Water Port, Galveston, Texas. Explosion damage es...
详细信息
The objective of the program reported in this paper was to assess the explosion and fire hazard associated with the crude-oil offloading facility proposed for the Deep Water Port, Galveston, Texas. Explosion damage estimates were made for two conditions;the ″worst case,″ which involved 36 percent of the tanks of the largest tanker. Fire effects were investigated on the basis of six fire scenarios. Fire-control techniques were postulated and equipment characteristics and quantities were defined. The inert-gas system (IGS) was evaluated in terms of operational characteristics, reliability, failure modes and effects, and controls.
The potential use of rudders as anti-roll devices has long been recognized. However, the possible interference of this secondary function of the rudder with its primary role as the steering mechanism has prevented, fo...
The potential use of rudders as anti-roll devices has long been recognized. However, the possible interference of this secondary function of the rudder with its primary role as the steering mechanism has prevented, for many years, the development of practical rudder roll stabilizers. The practical feasibility of rudder roll stabilization has, however, in recent years been demonstrated by two systems designed and developed for operational evaluation aboard two different U.S. C oast G uard Cutters, i.e., Jarvis and Mellon of the 3,000-ton, 378-foot HAMILTON Class. The authors describe the major components of the rudder roll stabilization (RRS) system, along with the design goals and methodology as applied to these first two prototypes. In addition, a brief history of the hardware development is provided in order to show some of the lessons learned. The near flawless performance of the prototypes over the past four years of operational use in the North Pacific is documented. Results from various sea trials and reports of the ship operators are cited and discussed. The paper concludes with a discussion of the costs and benefits of roll stabilization achieved using both a modern anti-roll fin system, as well as two different performance level RRS systems. The benefits of roll stabilization are demonstrated by the relative expansion in the operational envelopes of the USS OLIVER HAZARD PERRY (FFG-7) Class. The varying levels of roll stabilization suggest that the merits of fins and RRS systems are strongly dependent on mission requirements and the environment. The demonstrated performance of the reliable RRS system offers the naval ship acquisition manager a good economical stabilization system.
作者:
FROSCH, RAPresidentAmerican Association of Engineering Societies
Inc Dr. Robert A. Frosch born in New York City on 22 May 1928
attended Columbia University from which he received his B.A. degree in 1947 his M.A. degree in 1949 and his Ph.D. degree in 1952 all in the field of Theoretical Physics. While completing his studies for his doctorate he joined Columbia's Hudson Laboratories in 1951 and worked on naval research projects as a Research Scientist until 1958 when he became the Director Hudson Laboratories a post he held until 1963. From 1965 to 1966
he was Deputy Director Advanced Research Projects Agency (APRA) Department of Defense (DOD) having first joined ARPA in 1963 as the Director for Nuclear Test Detection the position he held until 1965. Since 1969 he also has served as the DOD member of the Committee for Policy Review National Council of Marine Resources and Engineering Development and in 1967 and 1970 as the Chairman of the U.S. Delegation to the Intergovernmental Oceanographic Commission meetings at UNESCO in Paris. In addition he was the Assistant Secretary of the Navy for Research & Development from 1966 to 1973 Assistant Executive Director of the United Nations Environment Program
with the rank of Assistant Secretary General of the United Nations from 1973 to 1975 and Assistant Director for Applied Oceanography at the Woods Hole Oceanographic Institution from 1975 until mid-1977.In June 1977
he became the Administrator of the National Aeronautics and Space Agency (NASA) the position he held prior to joining the American Association of Engineering Societies (AAES) Incorporated. On 20 January 1981 he was elected to his present post as President AAES. Additionally he was the Sea Grant Lecturer for the Massachusetts Institute of Technology in 1974 and currently is a National Lecturer for Sigma Xi. During his distinguished career
Dr. Frosch has been the recipient of numerous awards among which are the Arthur S. Flemming Award in 1966 the Navy Distinguished Public Service Award in 1
暂无评论