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1
Frumen, А. y C. Mednikov. "Multihull underwater vessel: design challenges". Transactions of the Krylov State Research Centre S-I, n.º 2 (28 de diciembre de 2020): 266–71. http://dx.doi.org/10.24937/2542-2324-2020-2-s-i-266-271.
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This paper discusses practicability of a large-diameter hull for an underwater vehicle as a totality of cylindrical shells with parallel axes forming a “global” cylinder (polyhull). Structural design is justified by analytical and numerical (FE) calculations of strength, structural stability and compression, with corresponding conclusions and recommendations.
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Gao, Feng, Jian Guo Zhang y Fang Fang Yang. "Stress Analysis and Optimization Design of Pressure Vessel of Underwater Gamma Spectrometer". Applied Mechanics and Materials 518 (febrero de 2014): 275–78. http://dx.doi.org/10.4028/www.scientific.net/amm.518.275.
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Pressure vessel makes the underwater gamma spectrometer can operation in underwater environment. In this paper, a kind of cylindrical pressure vessel has been simulated and analyzed using CAD software named Solidworks. Analysis results show the end covers are much thicker than the side wall to satisfy the same design safety factor and the centers of the end covers are the stress concentration areas. Further more, a 2× 2 LaBr3: Ce scintillation detector and a series of pressure vessels with various design safety factors and same inner space have been simulated by Monte Carlo code MCNP. Calculation indicates that the thicker the shell, the lower the detection efficiency. Further more, calculation shows the impact of the pressure vessel on detection efficiency of underwater gamma spectrometer varies with the photon energy. The law is that the higher the photon energy, the lower the influence on the detection efficiency.
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Li, Lin Na, Dong Wang Zhong y Chao Zhang. "Engineering Design of Underwater Explosive Containment Vessels". Applied Mechanics and Materials 303-306 (febrero de 2013): 2831–34. http://dx.doi.org/10.4028/www.scientific.net/amm.303-306.2831.
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Underwater explosion vessel is the main equipment to experimentally study the law of underwater explosion by small quantity of explosive. It is the main equipment of explosive metalworking. In order to the safe using of underwater explosion container and the efficiency, we must accurately determine the strength of the container. Based on the actual engineering design, the brief summary about engineering design method of 10gTNT equivalent deep water explosion vessel has carried on.
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Chukwunazo Joseph, Ezeofor y Georgewill Oyengiye Moses. "Prototype development of tethered underwater robot for underwater vessel anchor release". IAES International Journal of Robotics and Automation (IJRA) 9, n.º 3 (1 de septiembre de 2020): 196. http://dx.doi.org/10.11591/ijra.v9i3.pp196-210.
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<p>Tethered underwater robot (TUR) for underwater vessel anchor release is presented. In off-shore oil and gas enviromnment, there has been series of reported cases on stuck vessel anchors after mooring operations and divers are sent to release these anchors for the vessels to be in motion. The use of divers to perform such function is very risky because of human limitation and some divers have been reported dead on the process due to high pressure underwater or being attacked by underwater wide animals. This has caused very serious panic to the vessel owners and hence, this work is aimed to develop TUR that would be used by the vessel operators instead of divers to release the stuck anchor without loss. The underwater robot system comprises of three basic sections namely graphical user control interface (GUCI) that would be installed in the operator’s laptop, the WiFi LAN router for network connection, and TUR system hardware and software. Each of these sections was strictly designed. Various high-level programming languages were employed to design the GUCI and code the interface buttons, robot controller program codes etc. The implementation carried out and the prototype system tested in the University of Port Harcourt’s swimming pool of 6m depth for validation. The robot performed extremely good in swimming and release of constructed anchor underwater.</p>
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Morrissey, George R. y Michael C. Stone. "Diving Support Vessel Concept Design". Marine Technology and SNAME News 34, n.º 02 (1 de abril de 1997): 148–55. http://dx.doi.org/10.5957/mt1.1997.34.2.148.
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This paper describes the preliminary process for designing a 250 ft dynamically positioned, Diving Support Vessel. This is to serve the offshore oil industry as a platform for underwater intervention. Enlisting the use of the latest technological advances, the vessel will support both remotely operated vehicles and human divers. We will trace the development of this design with a well-defined agenda. Beginning with an analysis of the existing fleet, a practical hull form is created, which leads to solid estimations for hydrostatics, stability, resistance, powering and preliminary arrangements. We will also discuss the steps that will follow over the next several months.
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MacGillivray, Alexander O., Laurie M. Ainsworth, Joanna Zhao, Joshua N. Dolman, David E. Hannay, Héloïse Frouin-Mouy, Krista B. Trounce y Derek A. White. "A functional regression analysis of vessel source level measurements from the Enhancing Cetacean Habitat and Observation (ECHO) database". Journal of the Acoustical Society of America 152, n.º 3 (septiembre de 2022): 1547–63. http://dx.doi.org/10.1121/10.0013747.
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Measurements of the source levels of 9880 passes of 3188 different large commercial ships from the Enhancing Cetacean Habitat and Observation (ECHO) program database were used to investigate the dependencies of vessel underwater noise emissions on several vessel design parameters and operating conditions. Trends in the dataset were analyzed using functional regression analysis, which is an extension of standard regression analysis and represents a response variable (decidecade band source level) as a continuous function of a predictor variable (frequency). The statistical model was applied to source level data for six vessel categories: cruise ships, container ships, bulk carriers, tankers, tugs, and vehicle carriers. Depending on the frequency band and category, the functional regression model explained approximately 25%–50% of the variance in the ECHO dataset. The two main operational parameters, speed through water and actual draft, were the predictors most strongly correlated with source levels in all of the vessel categories. Vessel size (represented via length overall) was the design parameter with the strongest correlation to underwater radiated noise for three categories of vessels (bulkers, containers, and tankers). Other design parameters that were investigated (engine revolutions per minute, engine power, design speed, and vessel age) had weaker but nonetheless significant correlations with source levels.
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Ćorak, Maro, Zdenko Šperanda, Juvel Čokić, Marin Palaversa y Joško Parunov. "Finite Element Simulations of Novel Submersible Design Based on the ASME Design-by-Analysis Approach". Journal of Marine Science and Engineering 11, n.º 2 (25 de enero de 2023): 275. http://dx.doi.org/10.3390/jmse11020275.
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Tourist submersibles are a new class of underwater vehicles where new materials and innovative structural concepts are used. Because of the lack of experience with these innovative vessels, prescribed rules of classification societies are not directly applicable in their structural design. Thus, a novel design-by-analysis approach, as given in the Boiler and Pressure Vessel Code of ASME, is employed for dimensioning structural components. Design-by-analysis stands for a consistent set of loads, boundary conditions, modelling principles, failure modes, and safety factors if the finite element analysis is performed instead of using rule formulas. The approach has been used until now in the structural design and optimization of unconventional pressure vessels, while in this paper it is for the first time employed in structural design of the underwater vehicle. This study can serve as guidance for future applications of design-by-analysis in the development of the innovative structures exposed predominantly to the pressure loading.
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Li, Lin Na, Dong Wang Zhong y Chao Zhang. "Design and Research on 1kgTNT Equivalent Explosion Vessel". Advanced Materials Research 655-657 (enero de 2013): 648–51. http://dx.doi.org/10.4028/www.scientific.net/amr.655-657.648.
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In order to the safe using of underwater explosion container and the efficiency, we must accurately determine the strength of the container. In the paper, researching on the design of 1kgTNT equivalent cylindrical explosion vessel it is indicate that strength calculation to explosion vessel using the dynamic coefficient method is accuracy. Experimental results also show that the security of the explosion vessel has reached the design requirements.
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Tang, Ting, Li Jun Wang y Jin Bo Ma. "Optimal Design of Double Bottom Structure Filled with Liquid Resisting Underwater Explosion". Applied Mechanics and Materials 105-107 (septiembre de 2011): 907–11. http://dx.doi.org/10.4028/www.scientific.net/amm.105-107.907.
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Liquid filled double bottom structure is a usual type for large surface vessel, so the optimal design of which has important significance for viability of vessels in war. Appling a FEM process of MSC.Dytan, and changing the depth of liquid cabins, the thickness of bottoms and the thickness of stiffening, the response of different double bottom structures to underwater explosion were studied. After comparing and analyzing the deformation, the optimal design method of double bottom structures filled with liquid resisting underwater explosion was achieved. The best depth of water in water cabins is 90%, the best ratio of thickness of inner bottom and outer bottom is 11/9, and the stiffening should be thicker than outer bottom and thinner than inner bottom.
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Lerch, D. W. "An Application of Oil Spill Recovery Technology to Response Vessel Design—The Burrard Cleaner No. 9". Marine Technology and SNAME News 30, n.º 03 (1 de julio de 1993): 172–77. http://dx.doi.org/10.5957/mt1.1993.30.3.172.
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Part 1 examines the fate of crude oil spilled at sea and develops the design philosophy for the response recovery vessel. Part 2 describes the model testing, design details and construction of a 75-foot tractor design, modern oil recovery vessel for open water and coastal operation. Part 3 reviews the underwater appendage design, the problems and solutions.
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Pavan Kumar, GVV, V. V. S. Prasad y B. H. Nagesh. "Measurement of small vessel machinery vibration induced acoustic signature levels". Journal of Naval Architecture and Marine Engineering 16, n.º 2 (26 de diciembre de 2019): 87–98. http://dx.doi.org/10.3329/jname.v16i2.42030.
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Ship vibrations, airborne and underwater noise levels have always been a challenging topic from a performance point of view in ship design, building and operation. The measurement shall help in monitoring the self-noise and the technical state of their machinery mechanism. The vibration levels on the main engine and auxiliary Genset foundation, airborne noise levels of the engine room and underwater self-noise levels of a small mechanized fishing trawler was measured at the jetty in idling condition. The vibration levels on the foundation measured the average value of 0.207 mm/s for the main engine and 1.36 mm/s for auxiliary Genset. The airborne noise levels measured 99 dB (A) in the engine room. The peak underwater sound pressure levels measured 162 dB re 1µPa. The response spectra indicate the peak vibration and noise levels in the lower frequency region <1.2 kHz. The machinery excitation forces transferred to the hull surface as pressure fluctuations which generated the airborne and underwater noise levels. Though the measurement limited to jetty conditions, detailed analysis can be useful for detection, classification, and tracking of small vessels.
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Sunaryo y Pradhana Shadu Imfianto. "Electrical System Design of Solar-Powered Electrical Water Recreational and Sport Vessel". E3S Web of Conferences 130 (2019): 01029. http://dx.doi.org/10.1051/e3sconf/201913001029.
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Indonesia is the world’s largest archipelago with more than 17 000 islands, and the best marine tourism destination due to its beautiful beaches and underwater scenery, but Indonesia is also the most vulnerable country to be affected by climate change due to the greenhouse effect. Besides industry, the transportation sector is the highest contributor to the global greenhouse effect. In order to reduce the source of the greenhouse effect, the Indonesian Government has committed to using new and renewable energy as an alternative to fossil-based fuel. In an attempt to contribute to the Government’s efforts and to advance the national marine tourism, the research is aimed to design water recreational and sport vessel that powered by a solar generated electric engine, as further development of Universitas Indonesia’s solar boat participated in International Solar-boat Challenge competition in the Netherlands. The research is focused on the effective use of solar energy as the main source for powering the vessel’s electrical engine, based on the existing optimum shape and dimensions of the boat. Information and data regarding the arrangement of the vessel, solar electric generation processes and vessel powering system obtained from literature study, discussion with experts, and on the spot surveys of various recreational vessels were used as input for the calculation and simulation of the vessel being investigated. The research results are expected could be further developed for other related usages such as fish farming, coastal fishing rig, floating restaurant, etc.
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Huang, Tao Wei, Di Xiang Chen y Cheng Guang Fan. "Simulation and Design of Portable Underwater Acoustic Transducer Test Device". Applied Mechanics and Materials 599-601 (agosto de 2014): 445–50. http://dx.doi.org/10.4028/www.scientific.net/amm.599-601.445.
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In this paper, a portable underwater acoustic transducer sensitivity test device is designed to overcome the disadvantages of traditional test methods, such as the bigger size of anechoic pool, and single function of the vibrating column of liquid method. This new design has the advantage of small size, easy to carry and implement. A model of this device is constructed based on the finite element analyse software COMSOL Multiphysics. By calculating the sound field distribution of the test device model, the optimization size of the piezoelectric ceramic can be determined. Also the effect of some other key parameters, such as the material of vessel and thickness, are considered. All these results can provide the theoretical basement of the design of portable underwater acoustic transducer in practice.
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Blintsov, Vladimir S., Konstantin S. Trunin y Wiesław Tarełko. "Determination of Additional Tension in Towed Streamer Cable Triggered by Collision with Underwater Moving Object". Polish Maritime Research 27, n.º 2 (1 de junio de 2020): 58–68. http://dx.doi.org/10.2478/pomr-2020-0027.
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AbstractThe paper deals with issues connected with the behaviour of a streamer cable towed by a survey seismic vessel when the cable undergoes a strike triggered by collision with an underwater moving object. The consequences of such collisions may be both threat to the life of marine animals or damage to underwater units and large economic losses suffered by vessel owners. The risk of such collisions has increased over the last years as a result of increased offshore seismic survey operations. Therefore, a towed streamer should be very robust. To assure its robustness, we should know the deformation mechanism of a single streamer cable. This in turn requires the development of an appropriate mathematical model of such a phenomenon.In particular, the paper presents the characteristics of seismic survey vessels and streamers; an analysis of collisions that have occurred in the past; a statement of the problem, and a computer-aided system supporting simulation of the cable behaviour. To obtain all the necessary design parameters regarding the deformation mechanism of a streamer cable, we set up a dedicated computer-aided system that supports their calculation.
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Chou, Chun-Feng, Cheng-Mu Tsai, Chao-Hsien Chen, Yung-Hao Wong, Yi-Chin Fang, Chan-Chuan Wen, Hsiao-Yi Lee, Hien-Thanh Le, Shun-Hsyung Chang y Hsing-Yuan Liao. "Optical Design and Optimization with Genetic Algorithm for High-Resolution Optics Applied to Underwater Remote-Sensing". Applied Sciences 11, n.º 21 (30 de octubre de 2021): 10200. http://dx.doi.org/10.3390/app112110200.
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In fields such as biology, archeology, and industry, underwater photogrammetry can be achieved using consumer-grade equipment. However, camera operations underwater differ considerably from those on land because underwater photogrammetry involves different optical phenomena. On the basis of the requirements and specifications of the marine vessel Polaris, we developed a novel underwater camera with prime and zoom lenses and a high resolving power. The camera can be used in the spectrum in shallow water and the blue–green spectrum in deep water. In the past, ordinary cameras would be placed in waterproof airtight boxes for underwater photography. These cameras were not optimized to the underwater spectrum and environment, resulting in no breakthroughs in resolving power. Furthermore, the use of the blue spectrum greatly increases during underwater and particularly deep-water surveying. Chromatic aberration and focus-point displacement generated by the shift from the shallow-water spectrum to the blue–green spectrum in deep water makes universal underwater photography even more difficult. Our proposed optical design aimed to overcome such challenges for the development of a high-resolution underwater surveying camera. We designed a prime lens and a zoom lens. We adopted a waterproof dome window on the outer surface as the basic structure and optimized it in accordance with the conditions of different water depths and spectra to obtain distortion within ±2% and high-resolution underwater imaging quality. For the zoom lens design, we employed a genetic algorithm in Zemax to attenuate chromatic aberration as a kind of extended optimization. This novel optical design that can be used in all waters is expected to greatly reduce the volume and weight of conventional underwater cameras by more than 50% and 60%, respectively, and increase their resolving power by 30–40%.
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MacGillivray, Alexander O. y Laurie Ainsworth. "Quantifying uncertainty of shipping source levels for marine soundscape modeling". Journal of the Acoustical Society of America 151, n.º 4 (abril de 2022): A66. http://dx.doi.org/10.1121/10.0010679.
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Soundscape modeling is increasingly being used in assessments of marine habitat quality and to inform marine spatial planning. In most locations of interest, noise from shipping traffic and other marine vessels is the dominant anthropogenic contributor to the underwater soundscape. The noise contributions of marine vessels are typically calculated using tracking data from sources such as the automated identification system (AIS) and the vessel monitoring system (VMS). However, source levels of individual vessels in these datasets are often highly uncertain and must be estimated from incomplete information using data-driven models. Such models may be used to reliably predict mean source levels for large aggregations of vessels, but comparisons with real datasets show substantial statistical variability about the mean. Recent work, carried out using a large database of vessel noise measurements from the Enhancing Cetacean Habitat and Observation (ECHO) Program, has been used to develop statistical models that predict source levels based on ship type, design characteristics, and operating conditions. These models include a predictive component, based on observed trends, as well as a random component based on the residual variability of the data. This random component can be used to quantify the uncertainty of vessel noise emissions for soundscape modeling.
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Park, Eun-Young y Jungho Choi. "The Performance of Low-Pressure Seawater as a CO2 Solvent in Underwater Air-Independent Propulsion Systems". Journal of Marine Science and Engineering 8, n.º 1 (3 de enero de 2020): 22. http://dx.doi.org/10.3390/jmse8010022.
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Air-independent propulsion systems have improved the performance and decreased the vulnerability of underwater weapon systems. Reforming systems, however, generates large amounts of water and CO2. The recovery or separation of CO2, a residual gas component generated in vessels, entails considerable cost and energy consumption. It is necessary to understand the characteristics of the interaction between CO2 and seawater under the conditions experienced by underwater weapon systems to design and optimize a CO2 treatment process for dissolving CO2 in seawater. In this study, numerical analysis was conducted using the derived experimental concentration and MATLAB. The diffusion coefficient was derived as a function of temperature according to the CO2 dissolution time. Experiments on CO2 dissolution in seawater were conducted. The concentration of CO2 according to the reaction pressure and experimental temperature was obtained. The diffusion coefficient between CO2 and seawater was found to be 6.3 × 10−5 cm2/s at 25 °C and 7.24 × 10−5 cm2/s at 32 °C. CO2 concentration could be estimated accurately under vessel operating conditions using the derived CO2 diffusion coefficients. Optimal design of the residual gas treatment process will be possible using the derived seawater–CO2 diffusion coefficients under the actual operating conditions experienced by underwater weapon systems.
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YOSHIMURA, Yasuo y Yasunari KOYANAGI. "Design of a Small Fisheries Research Vessel with Low Level of Underwater-Radiated Noise". Journal of the Marine Acoustics Society of Japan 31, n.º 3 (2004): 137–45. http://dx.doi.org/10.3135/jmasj.31.137.
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Lee, Minuk, Soung-Jea Park, Tae-Kyeong Yeu, Hyong-Woo Ki, Sup Hong, Su-Gil Cho, Jun-Yong Jang, Tae Hee Lee y Jong-Su Choi. "Optimum Design of Underwater Connector Hole Arrangement for Deep-sea Pressure Vessel Cover Plate". Transactions of the Korean Society of Mechanical Engineers A 36, n.º 12 (1 de diciembre de 2012): 1627–33. http://dx.doi.org/10.3795/ksme-a.2012.36.12.1627.
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Takemura, Fumiaki, Reyes Tatsuru Shiroku, Kuniaki Kawabata y Shinichi Sagara. "Development of Easy-Removable Underwater Manipulator Unit with Built-in Controller". Journal of Robotics and Mechatronics 25, n.º 5 (20 de octubre de 2013): 778–84. http://dx.doi.org/10.20965/jrm.2013.p0778.
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In recent years, coral cover has been decreased by the impact of bleaching due to high water temperature, red-soil runoff, water pollution, and coral-eating starfish outbreak. It is necessary to appropriately measure, observe, and sample seawater. To succeed in these tasks, underwater robots should have a function of responds flexibly in solving problems. Underwater tasks are summarized as follows: (1) acquiring images and environmental information using cameras and sensors, (2) collecting objects and other necessary work using robot hands. Manipulator should be attached quickly to underwater robots as needed. So we have been developing “an easy-removable underwater manipulator.” The manipulators is easy to maintain because all electric components – DC motors, motor controllers, etc. – are in a pressure-resistant vessel, the manipulator has only one cable, and the manipulator is easy to attach and detach. In this paper, we illustrate the manipulator design and performance test results.
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Regina, Bruno A., Leonardo M. Honório, Antônio A. N. Pancoti, Mathaus F. Silva, Murillo F. Santos, Vitor M. L. Lopes, Accacio F. Santos Neto y Luis G. F. Westin. "Hull and Aerial Holonomic Propulsion System Design for Optimal Underwater Sensor Positioning in Autonomous Surface Vessels". Sensors 21, n.º 2 (15 de enero de 2021): 571. http://dx.doi.org/10.3390/s21020571.
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Acoustic Doppler Current Profiler (ADCP) sensors measure water inflows and are essential to evaluate the Flow Curve (FC) of rivers. The FC is used to calibrate hydrological models responsible for planning the electrical dispatch of all power plants in several countries. Therefore, errors in those measures propagate to the final energy cost evaluation. One problem regarding this sensor is its positioning on the vessel. If placed on the bow, it becomes exposed to flowing obstacles, and if it is installed on the stern, the redirected water from the boat and its propulsion system change the sensor readings. To improve the sensor readings, this paper proposes the design of a catamaran-like Autonomous Surface Vessel (ASV) with an optimized hull design, aerial propulsion, and optimal sensor placement to keep them protected and precise, allowing inspections in critical areas such as ultra-shallow waters and mangroves.
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Lowes, Gavin James, Jeffrey Neasham, Richie Burnett, Benjamin Sherlock y Charalampos Tsimenidis. "Passive Acoustic Detection of Vessel Activity by Low-Energy Wireless Sensors". Journal of Marine Science and Engineering 10, n.º 2 (12 de febrero de 2022): 248. http://dx.doi.org/10.3390/jmse10020248.
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This paper presents the development of a low-energy passive acoustic vessel detector to work as part of a wireless underwater monitoring network. The vessel detection method is based on a low-energy implementation of Detection of Envelope Modulation On Noise (DEMON). Vessels produce a broad spectrum modulated noise during propeller cavitation, which the DEMON method aims to extract for the purposes of automated detection. The vessel detector design has different approaches with mixtures of analogue and digital processing, as well as continuous and duty-cycled sampling/processing. The detector re-purposes an existing acoustic modem platform to achieve a low-cost and long-deployment wireless sensor network. This integrated communication platform enables the detector to switch between detection/communication mode seamlessly within software. The vessel detector was deployed at depth for a total of 84 days in the North Sea, providing a large data set, which the results are based on. Open sea field trial results have shown detection of single and multiple vessels with a 94% corroboration rate with local Automatic Identification System (AIS) data. Results showed that additional information about the detected vessel such as the number of propeller blades can be extracted solely based on the detection data. The attention to energy efficiency led to an average power consumption of 11.4 mW, enabling long term deployments of up to 6 months using only four alkaline C cells. Additional battery packs and a modified enclosure could enable a longer deployment duration. As the detector was still deployed during the first UK lockdown, the impact of COVID-19 on North Sea fishing activity was captured. Future work includes deploying this technology en masse to operate as part of a network. This could afford the possibility of adding vessel tracking to the abilities of the vessel detection technology when deployed as a network of sensor nodes.
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Zhang, Jiarui, Zhixun Xia, Liya Huang y Likun Ma. "Predicted performance of a two-phase underwater ramjet with a Laval nozzle". Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment 233, n.º 3 (21 de septiembre de 2018): 937–48. http://dx.doi.org/10.1177/1475090218795585.
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To predict engine performance and further instruct the integral engine design, a more reasonable and accurate numerical model of the two-phase underwater ramjet was introduced in this article by considering the bubble formation process. Two-fluid model was used to examine the bubbly flow in the nozzle and its mathematical model was solved by a fourth-order Runge–Kutta method. Subsequently, the influences of vessel velocity, gas mass flow rate, navigational depth, and orifice diameter of the bubble injector on the performance of the engine were discussed. Results show that, compared with convergent nozzle, Laval nozzle is proved to improve the thrust of the engine, especially at relatively high velocity and gas mass flow rate. With the other conditions fixed, there is an optimum vessel velocity for the ramjet, in which maximum thrust is generated. And a smaller orifice diameter always promotes the engine performance, while this promotion is negligible when the orifice diameter is smaller than 1 mm. Besides, increasing backpressure will cause serious performance drop, which means that the the two-phase underwater ramjet is only efficient for shallow depths.
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Brown, Hunter C., Liza K. Jenkins, Guy A. Meadows y Robert A. Shuchman. "BathyBoat: An Autonomous Surface Vessel for Stand-alone Survey and Underwater Vehicle Network Supervision". Marine Technology Society Journal 44, n.º 4 (1 de julio de 2010): 20–29. http://dx.doi.org/10.4031/mtsj.44.4.5.
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AbstractExploration of remote environments, once the domain of intrepid adventurers, can now be conducted in relative safety using unmanned vehicles. This article describes the joint University of Michigan (UMich) and Michigan Tech Research Institute’s project to design and to build a new autonomous surface vessel (ASV) for use in research, education, and resource management as well as in the commercial sector.Originally designed to assist with bathymetric surveys in the wilderness of northern Alaska, the BathyBoat has become a test-bed platform for new research in collaborative heterogeneous underwater robotic search and survey missions in ports, harbors, lakes, and rivers. The UMich Marine Hydrodynamics Laboratories are actively researching autonomous technologies such as cooperative navigation, surface vessel control, and multivehicle search and survey using the BathyBoat and the UMich Perceptual Robotics Laboratory’s Iver2 autonomous underwater vehicles.This article presents an overview of these research topics and highlights relevant real-world testing and recent missions involving the BathyBoat ASV on Alaska’s North Slope, the harbors of Illinois, and various riverine environments in Michigan.
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Zhu, Chenyang, Tomaso Gaggero, Nicholas C. Makris y Purnima Ratilal. "Underwater Sound Characteristics of a Ship with Controllable Pitch Propeller". Journal of Marine Science and Engineering 10, n.º 3 (25 de febrero de 2022): 328. http://dx.doi.org/10.3390/jmse10030328.
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The time-dependent spectral characteristics of underwater sound radiated by an ocean vessel has complex dependencies on ship machinery, propeller dynamics, hydrodynamics of ship exhaust and motion, as well as ship board activities. Here the underwater sound radiated by a ship equipped with a controllable pitch propeller (CPP) is analyzed and quantified via its (i) power spectral density for signal energetics, (ii) temporal coherence for machinery tonal sound, and (iii) spectral coherence for propeller amplitude-modulated cavitation noise. Frequency-modulated (FM) tonal signals are also characterized in terms of their frequency variations. These characteristics are compared for different propeller pitch ratios ranging from 20% to 82% at fixed propeller revolutions per minute (RPM). The efficacy and robustness of ship parameter estimation at different pitches are discussed. Finally, analysis of one special measurement is provided, when ship changes speed, propeller pitch and RPM over the duration of the measurement. The 50% pitch is found to be a crucial point for this ship about which tonal characteristics of its underwater radiated sound attain their peak values, while broadband sound and associated spectral coherences are at a minimum. The findings here elucidate the effects of pitch variation on underwater sound radiated by ships with controllable pitch propellers and has applications in ship design and underwater noise mitigation.
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Azarsina, Farhood, Mohammad Shahabadi y Arash Shadlaghani. "Numerical Derivation of Hydrodynamic Forces and Invention of a New Diving Technique for the Batoid Underwater Robot". Marine Technology Society Journal 50, n.º 5 (1 de septiembre de 2016): 59–73. http://dx.doi.org/10.4031/mtsj.50.5.7.
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AbstractAs part of a design project for a batoid-inspired underwater robot, its dive to a predetermined depth is questioned here. Previously, the vehicle was designed with a streamlined hull shape that resembles a Dasyatis batoid fish, and the fish locomotion was imitated using undulating fins at each side. We did not, however, provide a buoyancy engine or any fins to turn the vessel in the vertical plane and conduct diving maneuvers. We expect to leave the vessel on the water surface, and it dives to a desired depth and then maintains a constant pitch angle and a constant forward speed. A new technique is invented here: the thrust forces of the two fins are shifted off the central top-bottom symmetry plane of the hull, therefore producing a pitching moment on the vessel. An initial trim is also introduced by shifting the center of mass forward the center of buoyancy. Therefore, the vessel is initially bowed down and, by its out-of-plane thrust force, adjusts its pitch attitude. The question is whether a final balance between the thrust force and the hydrodynamic forces will be feasible. The hydrodynamic forces at such forward speeds and attack angles were numerically derived using the computational fluid dynamics powerful software ANSYS-CFX.
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Liu, Hanlin, Fuxian Gong y Oscar Curet. "Unleashing the Potential of Undulating Fin Propulsion Using a Biomimetic Robotic Vessel". Marine Technology Society Journal 51, n.º 5 (1 de septiembre de 2017): 79–93. http://dx.doi.org/10.4031/mtsj.51.5.7.
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AbstractUndulating fins are an excellent propulsion model for highly maneuverable underwater vehicles, due to their rich locomotor capabilities and high efficiency at moderate speed. In this study, we designed, developed, and tested a self-contained, free-swimming robotic device, the KnifeBot, to emulate the locomotor behaviors of knifefish, a typical fish that excels in using this type of propulsion. This novel biomimetic underwater vehicle uses an elongated ribbon-like fin composed of 16 fin rays interconnected by a compliant membrane as the propulsor. It features a slender 3D printed hull, 16 DC motors for actuating the fin rays, 2 Li-Ion batteries for providing power, wireless radio communication, and various sensors to measure acceleration, orientation, inside temperature, pressure and to detect leakage. We used this robotic device in two experimental sets: (1) the robot without pectoral fins to perform forward swimming, reversed swimming, and hovering maneuvers and (2) the robot with a pair of pectoral fins with fixed angle of attack (−5°) to perform forward swimming. In this paper, we focus on the design, implementation, and control of the robot. We also present the results of forward swimming velocity, power consumption, and Euler orientation angles of the robot with and without pectoral fins. Our results show that the cost of transport follows a V-shape trend with the lowest point at low swimming speed, indicating the undulating fin propulsion is more efficient at low speeds. For the cases studied, the Strouhal number, St, ranges from 0.5 to 0.2 with the best cost-of-transport corresponding to St = 0.2. We found that the airfoil-like pectoral fins at small negative angles of attack slightly slow down the speed of the robotic vessel and reduce its pitch angle. The robot can take advantage of the pectoral fins to control its maneuver from swimming at the water surface to rapid diving. Our findings demonstrate that undulating fin-based propulsion has the potential to enhance the mobility and performance of underwater vehicles navigating in complex environments.
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Siqueira Nóbrega de Freitas, Artur, Alexander Alfonso Alvarez, Roberto Ramos y Ettore Apolonio de Barros. "Buckling Analysis of an AUV Pressure Vessel with Sliding Stiffeners". Journal of Marine Science and Engineering 8, n.º 7 (14 de julio de 2020): 515. http://dx.doi.org/10.3390/jmse8070515.
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The structure of an autonomous underwater vehicle (AUV), usually composed of a cylindrical shell, may be exposed to high hydrostatic pressures where buckling collapse occurs before yield stress failure. In conventional submarines, welded stiffeners increase the buckling resistance, however, in small AUVs, they reduce the inner space and cause residual stresses. This work presents an innovative concept for the structural design of an AUV, proposing the use of sliding stiffeners that are part of the structure used to accommodate the electronics inside it. Since the sliding stiffeners are not welded to the shell, there are no residual stresses due to welding, the AUV fabrication process is simplified, enabling a reduction of the manufacturing cost, and the inner space is available to accommodate the equipment needed for the AUV mission. Moreover, they provide a higher buckling resistance when compared to that of an unstiffened cylindrical shell. A comparative analysis of the critical buckling loads for different shell designs was carried out considering the following: (i) the unstiffened shell, (ii) the shell with ring stiffeners, and (iii) the shell with sliding stiffeners. Results evidenced that major advantages were obtained by using the latter alternative against buckling.
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Aktas, Batuhan, Naz Yilmaz, Mehmet Atlar, Noriyuki Sasaki, Patrick Fitzsimmons y David Taylor. "Suppression of Tip Vortex Cavitation Noise of Propellers using PressurePoresTM Technology". Journal of Marine Science and Engineering 8, n.º 3 (1 de marzo de 2020): 158. http://dx.doi.org/10.3390/jmse8030158.
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This study aims to demonstrate the merits of pressure-relieving holes at the tip region of propellers, which is introduced as “PressurePoresTM” technology as a retrofit on marine propellers to mitigate tip vortex cavitation noise for a quieter propeller. Shipping noise originates from various sources on board a vessel, amongst which the propeller cavitation is considered to dominate the overall radiated noise spectrum above the inception threshold. Thus, by strategically introducing pressure-relieving holes to modify the presence of cavitation, a reduction in the overall cavitation volume can be achieved. This mitigation technique could consequently result in a reduction of the radiated noise levels while maintaining the design efficiency as much as possible or with the least compromise. The strategic implementation of the holes was mainly aimed to reduce the tip vortex cavitation as this is one of the major contributors to the underwater noise emissions of a ship. In this paper, the details and results of a complementary numerical and experimental investigation is presented to further develop this mitigation concept for underwater radiated noise (URN) and to validate its effectiveness at model scale using a research vessel propeller. An overall finding from this study indicated that a significant reduction in cavitation noise could be achieved (up to 17 dB) at design speed with a favourable strategic arrangement of the pressure pores. Such a reduction was particularly evident in the frequency regions of utmost importance for marine fauna while the propeller lost only 2% of its efficiency.
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Celik, Fahri y Mesut Guner. "An Improved Lifting Line Model for the Design of Marine Propellers". Marine Technology and SNAME News 43, n.º 02 (1 de abril de 2006): 100–113. http://dx.doi.org/10.5957/mt1.2006.43.2.100.
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This paper describes a procedure for the design of marine propellers where more realistic representation of the slipstream shape by the trailing vortex system is taken into account. The slipstream shape behind the propeller is allowed to deform and to align with the direction of local velocity, which is obtained by the sum of the inflow velocity and induced velocities due to the trailing vortices. In classical lifting line approaches, that deformation is neglected. Applications for an autonomous underwater vehicle (AUV) and a fishing vessel are carried out to demonstrate propeller design and the effect of the slipstream contraction. Furthermore, a computational fluid dynamics (CFD) analysis based on the finite volume method and experimental validation of the method are carried out for the propellers. CFD analysis and experimental results are compared with the results obtained from present method.
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Zou, Chun-Ping, Duan-Shi Chen y Hong-Xing Hua. "Investigation of Ship Structural Vibration and Underwater Radiation Noise". Journal of Ship Research 47, n.º 04 (1 de diciembre de 2003): 275–89. http://dx.doi.org/10.5957/jsr.2003.47.4.275.
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Underwater radiation noise is a very important factor for most ships, such as fishing boats, warships, and so forth. The magnitude of its energy depends on the vibration of the hull in contact with water. The vibration of the hull caused by the power plant, while the vessel is cruising, is the dominant source of underwater radiation noise, which is the subject of our investigation. In this paper, the coupled finite element/boundary element method is used to investigate ship structural vibration and underwater radiation noise. The finite element method (FEM) is employed to analyze modes and vibration responses of an entire ship for different kinds of excitations in consideration of fluid-structure interaction. The boundary element method (BEM) is used to analyze the underwater radiation noise. A FEM model is first constructed by using 30 geometric parameters and five kinds of finite elements. Then, the reduced matrix method is used to eliminate the local modes in order to obtain the overall bending and torsional modes of the ship. Last, vibration displacements of the hull are treated as the velocity boundary condition of BEM to calculate underwater radiation noise. Numerical results show thatthe calculated sound-pressure levels of underwater radiation noise are in a good agreement with experimentally measured results;although the vibration isolator is used, the propulsion diesel engine is the dominant source of the underwater radiation noise among all machines in the engine room and the maximum sound-pressure levels increase as the sailing speed of the ship increases;the underwater radiation noise of the ship with gearbox excitation is greater than that of the ship with diesel generator set excitation, which should be noticed by the ship designers during the design stage.
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Azarsina, Farhood. "Designing a Hydrodynamic Shape and Thrust Mechanism for a Batoid Underwater Robot". Marine Technology Society Journal 50, n.º 5 (1 de septiembre de 2016): 45–58. http://dx.doi.org/10.4031/mtsj.50.5.6.
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AbstractGiven the facts that a vast area of the earth is covered by water and the average depth of the oceans is more than 3,000 m, the issue of the unknowns beneath the water surface is a challenging and questionable one. It has been a few decades since remotely operated vehicles as well as untethered underwater robots have appeared and elevated the level of complex engineering. In this category, underwater robots that mimic fish and aquatic creatures open new horizons. In this article, imitating the body shape, kinematics, and swimming mechanism of a batoid fish (Dasyatidae), a vessel is designed that can swim at an acceptable speed with a limited amount of power. The hull shape is based on a cardioid curve, and drag force is calculated using fundamentals of fluid mechanics. Propulsion of the robot-fish is two wings at starboard and port that are undulating backward; thrust is approximated versus shaft speed. Finally, the power for swimming at the design speed is evaluated and compared with the available data of similar orders of magnitude.
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Codiga, Daniel L. "A Marine Autonomous Surface Craft for Long-Duration, Spatially Explicit, Multidisciplinary Water Column Sampling in Coastal and Estuarine Systems". Journal of Atmospheric and Oceanic Technology 32, n.º 3 (marzo de 2015): 627–41. http://dx.doi.org/10.1175/jtech-d-14-00171.1.
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AbstractThe Surveying Coastal Ocean Autonomous Profiler (SCOAP) is a large catamaran marine autonomous surface craft (MASC) for unattended weeks-long, spatially explicit, multidisciplinary oceanographic water column profile sampling in coastal/estuarine waterbodies. Material transport rates/pathways, crucial to understanding these ecosystems, are typically poorly known. SCOAP addresses demanding spatiotemporal sampling needs and operational challenges (strong currents, open coastal sea states, complex bathymetry, heavy vessel traffic). Its large size (11-m length, 5-m beam) provides seaworthiness/stability. The average speed of 2.5 m s−1 meets the representative goal to traverse an 18-km transect, sampling 10 min at each of 10 stations 2 km apart, nominally 4 times daily. Efficient hulls and a diesel–electric energy system can provide the needed endurance. The U.S. Coast Guard guidelines are followed: lighting, code flags, the Automatic Identification System (AIS), and collision avoidance regulations (COLREGs)-based collision avoidance (CA) by onboard autonomy software. Large energy reserves obviate low-power optimization of sensors, enabling truly multidisciplinary sampling, and provide on-demand propulsion for effective CA. Vessel stability facilitates high-quality current profile observations and will aid engineering/operation of the planned winched profiling system, performance of an anticipated radar system to detect/track non-AIS vessels, and potential research-quality meteorological sensor operation. A Narragansett Bay test deployment, attended by an escort vessel, met design goals; an unattended open coastal deployment is planned for Rhode Island Sound. Scientific and operational strengths of large catamaran MASCs suggest they could be an important cost-effective complement to other sampling platforms (e.g., improved spatiotemporal coverage and resolution, extending farther inshore, with a broader range of sensors, compared to underwater gliders) in coastal/estuarine waters.
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Xie, Chao, Lan Wang, Ning Yang, Casey Agee, Ming Chen, Jinrong Zheng, Jun Liu et al. "A Compact Design of Underwater Mining Vehicle for the Cobalt-Rich Crust with General Support Vessel Part A: Prototype and Tests". Journal of Marine Science and Engineering 10, n.º 2 (20 de enero de 2022): 135. http://dx.doi.org/10.3390/jmse10020135.
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This paper proposed a compact design of the subsea cobalt-rich crust mining vehicle with a general purpose support vessel for subsea resource exploration, sample collection, and research. The necessary functions were considered in the concept design, including walk, crushing/mining, sample collection, cutter head adaptation, vehicle orientation, crust texture measurement, awareness, positioning, and navigation. The prototype was tested in both tank and subsea environment. The sea trials were carried out with the support of a general purpose support vessel. The track design worked well in both the tank and subsea environment and the mining vehicle walked smoothly in the sea trial. The crust was crushed to the size of 2 mm and 10 mm with different cutting parameters and successfully collected by the jet pump, 6 kg in total. The crust texture was measured by the onboard sonar successfully and can be used for cutting parameter selection. The cameras captured the images of the subsea environment, but the actions of crushing and sample collection produced plumes, which blocked the camera vision. In the situation, the front image sonar can be used to keep the vehicle away from big rocks. The mining vehicle is not limited to the mining and sampling of subsea cobalt-rich crust. Most of the subsea solid resources on the seabed can be considered to use the compact mining vehicle for sampling and related research. The only issues to be considered are the crushing ability and sample size required.
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Grządziela, Andrzej y Marcin Kluczyk. "Preliminary Calculations for Minehunter's Genset Foundations". Transactions on Maritime Science 8, n.º 1 (20 de abril de 2019): 54–61. http://dx.doi.org/10.7225/toms.v08.n01.006.
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The requirements for the foundations of naval vessel engines are based on classification rules devised by classification societies or/and military standardization rules. A class guideline was published, defining the requirements, acceptance criteria and machinery seating methods. There is also a schedule of basic calculation procedures for cast resin or rubber chocks which facilitates the process of machinery foundation design, preloading force calculation, the establishment of boundary conditions etc. In case of naval vessels, typical procedures do not meet tactical requirements due to potential explosion loads. Since minehunters are mainly deployed at sea, handling active, naval mines, the shock resistance calculation for the entire machinery, including the Genset, is required. The paper presents preliminary MatLab calculation methods which can be used to analyse the type, number and location of rubber or elastomer chocks. The procedure consists of input data such as UNDEX pressure and technical data of the Genset used in the Polish Navy. Calculation results include the analysis of the dynamic interaction between the Genset and the foundation, as well as the damping effect generated by the UNDEX (UNDerwater EXplosion) shock pulse.
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Pan, Shou Li y Qiang Zhou. "Natural Supercavitation Characteristic Simulation of Small-Caliber Projectile". Applied Mechanics and Materials 488-489 (enero de 2014): 1243–47. http://dx.doi.org/10.4028/www.scientific.net/amm.488-489.1243.
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Based on the multiphase model of FLUENT 6.3,a underwater projectile cavitation model is established for a new designed underwater projectile which have a disc cavitator.Then the cavitation number influence on cavitation form is concerned and contrast with the empirical formula of cavitation form.The conclusion is：with the increase of cavitation number,the drag coefficient will increase non-linear;the cavitation slenderness radio is greater,the drag coefficient is smaller. Supercavitation phenomenon is that when a object moves in water and it’s speed increases constantly, according to Bernoulli's equation, this will make the hydrostatic pressure that it bears drop. And when the pressure down to the vaporization pressure of water at that temperature, the surface moisture of the object will change into steam, form bubbles and wrap it. Due to the density of water and steam has magnitude deviation, the viscous resistance acting on the underwater moving object will reduce greatly, that can make the performance of underwater weapon enhance markedly. In the military applications, there are represented by Russia, the torpedo of “snowstorm” used the ventilation supercavitation theory and, represented by USA, the “20mm Supercavitation projectile” used the nature supercavitation theory. Facing the daily intelligentized contrail guided torpedo and mine, the small caliber supercavitation projectile technology has provided a new method for the short-range defense of surface vessel. As the nature supercavition projectile is a kind of uncontrolled, unpowered underwater weapon, the formation and stability of cavitation are more significative for performing the properties of projectile. The paper has done same simulate calculation for a new designed subcaliber supercavitation projectile, focused on the cavitation morphology and drag reduction ability under several different projectile velocity circumstance. This research can provide same basis for reasonable structure design of new projectiles.
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Varshney, Nidhi, Siva Rajesh, Anantha Padmanabhan Aarthi, Narayanmurthy Renganayahi Ramesh, Narayanswamy Vedachalam, Gidugu Ananda Ramadass y Malayath Aravindakshan Atmanand. "Estimation of Reliability of Underwater Polymetallic Nodule Mining Machine". Marine Technology Society Journal 49, n.º 1 (1 de enero de 2015): 131–47. http://dx.doi.org/10.4031/mtsj.49.1.4.
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AbstractThis paper presents the reliability analysis carried out on the subsystems of the underwater polymetallic nodule mining machine developed by National Institute of Ocean Technology, India, which is being enhanced for polymetallic nodule mining technology demonstration at 6,000-m water depth in the Central Indian Ocean Basin, where manganese nodules are available in abundance. The mining machine, which is a tracked vehicle, was successfully demonstrated at a water depth of 512 m, wherein the nodules are collected, crushed, and pumped to the mother vessel. Reliable long-term operation at 6,000 m is the key factor, as retrieval of the system to the top side for rectification is costly and time-consuming. It is identified that the reliability of the 6,000-m-rated mining machine subsystems could be improved by the use of localized control power, redundant electronics, and hydraulic systems. It is estimated that, with the suggested improvements, the probability of failure of the systems involved in vehicle maneuvering, mineral crushing, and pumping could be reduced from 91%, 88.8%, and 84.59% to 68%, 57%, and 39%, respectively, when the systems are operated for a period of 1,460 h in a year. The results serve as a guideline for 6,000-m-depth-rated mining machine system design with a trade-off on size, weight, and required level of reliability.
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Yang, D., XQ Lv y YL Xiong. "A computational fluid dynamics study on the solid mineral particles-laden flow in a novel offshore agitated vessel". Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment 233, n.º 2 (25 de mayo de 2018): 622–31. http://dx.doi.org/10.1177/1475090218776143.
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Most seabeds are unexplored and rich in mineral deposits, making offshore mining a promising activity. However, offshore operation brings in great challenges from technical equipment to physical space. For instance, an offshore agitated vessel is supposed to stabilize the solids concentration from the underwater mining and make little impact on the stability of the platform or ship. For this reason, we proposed a novel offshore agitated vessel. The whole system based on the arrangement of the mineral processing platform and the slurry mix flow rate is obtained from the previous design stage. Large-scale unsteady computational fluid dynamics simulations are performed to calculate its effectiveness. The simulation model equipped with two pitched blade turbines and inlets/outlets is investigated. A classical Eulerian multiphase model and a modification of the standard k-ε eddy-viscosity turbulence model are adopted to simulate the dense solid–liquid suspension dynamics. Computational fluid dynamics results were found to be in satisfactory agreement with the theoretical predictions. The agitated system obtained was found to be effective to stabilize the solid particle concentration. In order to achieve a higher concentration at outlets and lower power consumption, further improvement was made and validated by computational fluid dynamics simulations. The proposed offshore mechanical agitated vessel could be equipped on offshore mining.
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Haq, Mazhar Ul, Zhao Gang, Shaban Usman, Anees Ur Rehman y S. M. Aftab. "Forward Kinematic Analysis of IPMC Actuated Three Link Mechanism for Fin Actuation of Fish Like Micro Device". Journal of Biomimetics, Biomaterials and Biomedical Engineering 23 (junio de 2015): 67–75. http://dx.doi.org/10.4028/www.scientific.net/jbbbe.23.67.
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IPMC is becoming an increasingly popular material among scholars, engineers and scientists due to its inherent properties of low activation voltage, large bending strain, flexibility, softness, suitable response time which make them a strong candidate to be applied as artificial muscle in biomimetic land and underwater applications. The applications of IPMC have been growing due to progression in its manufacturing techniques, development of more accurate response models and control techniques, and recently more sophisticated IPMC actuator applications have been performed. In this paper, a new application of IPMC is proposed to actuate aileron fins of a micro scanning device towed underwater by a surface vessel to control its depth and to stabilize it against roll motion that can mimic pectoral fins of fish that steer them up and down by changing their angle of rotation and their dorsal fins that keep them upright against roll. Same is applicable for autonomous underwater vehicles. Secondly, a three link mechanism is presented to actuate aileron fin through IPMC actuator. Three dimensional model of the mechanism is developed in Pro-Engineer CAD software tool and its kinematic analysis is performed. Thirdly, forward kinematic model of proposed mechanism, based on geometric coordinate, is presented. Lastly, results of kinematic analysis of proposed mechanism are compared to that of model to verify its design and kinematics. Encouraging results decoy the research team to manufacture the mechanism and to perform experiments for its practical application.
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Rowinski, Lech y Maciej Kaczmarczyk. "Evaluation of Effectiveness of Waterjet Propulsor for a Small Underwater Vehicle". Polish Maritime Research 28, n.º 4 (1 de diciembre de 2021): 30–41. http://dx.doi.org/10.2478/pomr-2021-0047.
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Abstract The goal of the project described is to replace the existing propulsion system of a small underwater vehicle with a solution less prone to mechanical damage and ensuring a lower risk of the entanglement of fibrous objects suspended in the body of water. Four typical marine screws are utilised in the current design of the vehicle. One possible solution of the problem is the application of waterjet propulsors located inside the body of the vehicle instead. The general condition of the application of the new solution was to secure at least the same motion control capabilities of the vehicle while the basic capability is its propulsion effectiveness at the required speed. Specific features of the considered waterjet propulsor, when compared with their application in surface vessel propulsion, are the lack of the head losses and the low significance of cavitation issues. One of the difficulties in the considered case is the small diameter of the propulsor in comparison to commercially available waterjet units, which have diameters between 0.1 [m] and 1.0 [m]. There is very little data regarding the design and performance of devices in the 0.02 to 0.05 [m] range. Methods utilised to forecast the performance of the new propulsion system are presented and results compared. These were semi-empirical calculations, numerical calculations and tests of real devices. The algorithm that is based on semi-empirical calculations is of particular interest while it offers possibility quick assessment of performance of a propulsor composed of several well defined components. The results indicate the feasibility of modification of the propulsion system for the considered vehicle if all the existing circumstances are taken into account.
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Joung, Tae-Hwan, Jae-Hwan Lee, In-Sik Nho, Chong-Moo Lee, Pan-Mook Lee, Taro Aoki y Tadahiro Hyakudome. "A study on the pressure vessel design, structural analysis and pressure test of a 6000 m depth-rated unmanned underwater vehicle". Ships and Offshore Structures 3, n.º 3 (22 de agosto de 2008): 205–14. http://dx.doi.org/10.1080/17445300802204371.
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Haq, Mazhar Ul, Zhao Gang, Fazl E. Ahad, Anees Ur Rehman y Muhammad Hussain. "Inverse Kinematic Analysis of Three Link Mechanism for Fin Actuation of Fish Like Micro Device". Journal of Biomimetics, Biomaterials and Biomedical Engineering 24 (julio de 2015): 77–81. http://dx.doi.org/10.4028/www.scientific.net/jbbbe.24.77.
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In this paper, inverse kinematic analysis of a proposed three link mechanism of a bio-inspired micro scanning device towed underwater by a surface vessel to actuate its aileron fins for its depth control and for its stabilization against roll is performed. Mechanism is actuated by IPMC actuators. To speed up the design verification process, computer aided simulations are used to perform motion analysis of the proposed IPMC actuated mechanism through Pro/Mechanism tool. Inverse kinematic analysis is performed to find out the joint variables of the mechanism to realize fin actuation along desired path. Displacements, velocities and accelerations of the links constructing mechanism are found out to establish their interrelationship. Results are analysed for the study of mechanism efficacy and for sizing the IPMC actuators. This paper contributes to introduce a new approach of virtual prototyping using advanced simulation tools for analysis and design verification of IPMC actuated mechanisms for biomimetic applications before moving into functional prototype stage.
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Nsalo Kong, Darryl Franck, Chong Shen, Chuan Tian y Kun Zhang. "A New Low-Cost Acoustic Beamforming Architecture for Real-Time Marine Sensing: Evaluation and Design". Journal of Marine Science and Engineering 9, n.º 8 (12 de agosto de 2021): 868. http://dx.doi.org/10.3390/jmse9080868.
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This paper mainly studies the performance of an acoustic beamforming technique applied to a low-cost hydrophone in a linear array of two to four elements for the detection and localization of underwater acoustic sound waves. It also evaluates the integration of the array in an energy-efficient real-time monitoring system architecture, allowing marine sensing to be conducted without human intervention. Such architecture would consist of vertical linear arrays of two or four RHSA-10 hydrophones models attached to a buoy or a vessel for sound detection; a frequency domain beamformer (FDB) technique implemented in a Xilinx Spartan-7 field programmable gate array (FPGA) for sound source localization; a LoRa wireless sensor network mote to provide convenient access from a base center. The architecture aims to alleviate sea traffic control for countries that lack the financial resources to properly address illegal fishing or piracy issues, mostly committed in small fast motorized boats. In our experiment, the sound waves emitted by a small motorized boat were successfully detected and tracked by three data acquisitions at a 1 km range. It is demonstrated that a system using a small number of hydrophones is capable of producing robust accuracy over a large band frequency in the presence of noise interference.
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Chen, Chen-Wei y Yi-Fan Lu. "Computational Fluid Dynamics Study of Water Entry Impact Forces of an Airborne-Launched, Axisymmetric, Disk-Type Autonomous Underwater Hovering Vehicle". Symmetry 11, n.º 9 (2 de septiembre de 2019): 1100. http://dx.doi.org/10.3390/sym11091100.
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An autonomous underwater hovering vehicle (AUH) is a novel, dish-shaped, axisymmetric, multi-functional, ultra-mobile submersible in the autonomous underwater vehicle (AUV) family. Numerical studies of nonlinear, asymmetric water entry impact forces on symmetrical, airborne-launched AUVs from conventional single-arm cranes on a research vessel, or helicopters or planes, is significant for the fast and safe launching of low-speed AUVs into the target sea area in the overall design. Moreover, a single-arm crane is one of the important ways to launch AUVs with high expertise and security. However, AUVs are still subject to a huge load upon impact during water entry, causing damage to the body, malfunction of electronic components, and other serious accidents. This paper analyses the water entry impact forces of an airborne-launched AUH as a feasibility study for flight- or helicopter-launched AUHs in the future. The computational fluid dynamics (CFD) analysis software STAR-CCM+ solver was adopted to simulate AUH motions with different water entry speeds and immersion angles using overlapping grid technology and user-defined functions (UDFs). In the computational domain for a steady, incompressible, two-dimensional flow of water with identified boundary conditions, two components (two-phase flow) were modeled in the flow field: Liquid water and free surface air. The variations of stress and velocity versus time of the AUH and fluid structure deformation in the whole water entry process were obtained, which provides a reference for future structural designs of an AUH and appropriate working conditions for an airborne-launched AUH. This research will be conducive to smoothly carrying out the complex tasks of AUHs on the seabed.
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Matthews, Michael L., Jeff Bos, Jacquelyn M. Crebolder y Sharon McFadden. "Modeling the Effectiveness of Tools to Assist Sonar Operators". Proceedings of the Human Factors and Ergonomics Society Annual Meeting 49, n.º 12 (septiembre de 2005): 1124–28. http://dx.doi.org/10.1177/154193120504901205.
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The task of building the underwater picture from sonar data is made complex by high volumes of noise and multiple data that arrive from a variety of acoustic sources detected at great distances by modern, sonar equipment. Typically, acoustic sources from ships have a complex spectrum consisting of several base frequency components and related harmonics. The task for operators is to analyse the data to determine if there is a pattern that represents the signature of a known source, thereby leading to identification of a vessel. Since the task can be highly labour intensive automated decision aids may be of value to the operator. This project addresses how to predict and optimise the impact of new technologies in system re-design by using a modeling/simulation approach to operator-system functionality. A generic sonar analysis process was simulated and the effectiveness of a decision aid evaluated. The improvement in performance predicted by the aid was then validated experimentally.
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Kraft, Martin, Michael Jakusch, Manfred Karlowatz, Abraham Katzir y Boris Mizaikoff. "New Frontiers for Mid-Infrared Sensors: Towards Deep Sea Monitoring with a Submarine FT-IR Sensor System". Applied Spectroscopy 57, n.º 6 (junio de 2003): 591–99. http://dx.doi.org/10.1366/000370203322005256.
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A sub-sea deployable fiber-optic sensor system for the continuous determination of a range of environmentally relevant volatile organic compounds in seawater has been developed. The prototype of a robust, miniaturized Fourier transform infrared (FT-IR) spectrometer for in situ underwater pollution monitoring was designed, developed, and built in our research group. The assembled instrument is enclosed in a sealed aluminium pressure vessel and is capable of maintenance-free operation in an oceanic environment down to depths of at least 300 m. The whole system can be incorporated either in a tow frame or a remotely operated vehicle (ROV). A suitable fiber-optic sensor head was developed, optimized in terms of sensitivity and hydrodynamics, and connected to the underwater FT-IR spectrometer. Due to a modular system design, various other sensor head configurations could be realized and tested, ensuring facile adaptation of the instrument to future tasks. The sensor system was characterized in a series of laboratory and simulated field tests. The sensor proved to be capable of quantitatively detecting a range of chlorinated hydrocarbons and monocyclic aromatic hydrocarbons in seawater down to the low ppb (μg/L) concentration range, including mixtures of up to 6 components. It has been demonstrated that varying amounts of salinity, turbidity, or humic acids, as well as interfering seawater pollutants, such as aliphatic hydrocarbons or phenols, do not significantly influence the sensor characteristics. In addition, the sensor exhibits sufficient long-time stability and a low susceptibility to sensor fouling.
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Liestøl, Gunnar, Michael Bendon y Elpida Hadjidaki-Marder. "Augmented Reality Storytelling Submerged. Dry Diving to a World War II Wreck at Ancient Phalasarna, Crete". Heritage 4, n.º 4 (11 de diciembre de 2021): 4647–64. http://dx.doi.org/10.3390/heritage4040256.
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Underwater heritage and archaeology is, in general, limited to the few who have permission, and the means to actually dive on location and experience the submarine sites. Dry dive technologies such as Augmented Reality (AR) now offer unprecedented opportunity to change this situation. This paper explores the use of AR storytelling with regard to a World War II landing craft at Phalasarna, Greece. Tank Landing Craft A6 (TLC) was sunk by German aircraft while evacuating Allied troops from Crete in 1941. Its remains still lie just off the coast in a few metres of water. This project revolves around the development of a 3D–animation to make the site more accessible to those who cannot dive. By visually reconstructing the dramatic event of the craft’s final moments under German attack before it settled to the seabed, as well as the site’s present condition, visitors can experience and learn more about both the vessel itself and the historical context. The Indirect AR simulation contains two main modes: a dry dive reconstruction of the wreck as it looks today with detailed multimodal explanations based on historical and archaeological research, and an animation sequence that reconstructs the actual German attack on the ship. This article presents detailed descriptions of the site’s historical background, of the vessel and the design challenges involved in the production process of the app itself. Feedback provided by visitors who recently tested the AR simulation on location is also reported here.
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M R, Subash Chandrabose, Shan Victor Pereira, Jayakumar B y Ebenezer D. D. "Metal Ceramic Segmented Ring Transducer under Deep Submergence Conditions". Defence Science Journal 67, n.º 6 (6 de noviembre de 2017): 612. http://dx.doi.org/10.14429/dsj.67.11201.
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<p class="p1">Segmented ring transducers are widely used for low frequency, broadband, deep submergence applications. These transducers can be made out of piezoceramic wedges or slabs and metallic wedges. Higher diameter, low frequency transducers are generally made out of piezoceramic slabs and metal wedges due to ease of manufacture and low cost. In this paper, metal ceramic segmented ring transducers are modelled using ATILA, a finite element software for the design of underwater transducers. Transducer variants were modelled with different wedge and piezoceramic materials. Transducers modelled were manufactured, assembled and tested. Various stages of manufacture like piezoceramic stacking, transducer assembly, pre-stressing with fibre winding, and encapsulation are explained. Acoustic performances of the transducers manufactured were measured in an open tank and inside a pressurised vessel from 10 bar to 70 bar. Performance parameters like resonance frequency, transmitting voltage response and directivity were measured. Results indicate that the transducer has usable bandwidth of about two octaves and stable response. One of the transducers was also tested in a high pressure test facility at 600 bar to check its pressure withstanding capability.</p>
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Klis, Pawel, Shuaishuai Wang y Yihan Xing. "Technical and Economic Feasibility Analysis of a Conceptual Subsea Freight Glider for CO2 Transportation". Journal of Marine Science and Engineering 10, n.º 8 (12 de agosto de 2022): 1108. http://dx.doi.org/10.3390/jmse10081108.
Texto completoResumen
This study analyses the technical and economic aspects of a novel subsea freight glider (SFG). The SFG is an excellent replacement for tanker ships and submarine pipelines transporting liquefied CO2. The main aim of the SFG is to ship CO2 from an offshore facility to an underwater well where the gas can be injected; as an advantage, the SFG vehicle may be used to transport all kinds of cargo. The SFG travels below the sea surface, making the vessel weather-independent. The research is divided into two steps. Firstly, the technical feasibility analysis is performed by designing a baseline design with a length of 56.5 m, a beam of 5.5 m, and a cargo volume of 1194 m3. The SFG is developed using DNVGL-RU-NAVAL-Pt4Ch1, which was initially created for military submarine designs. Two additional half-scaled 469 m3 and double-scaled 2430 m3 models are created when the baseline design fulfils the technical requirements. Secondly, the economic analysis is carried out using the freely accessible MUNIN D9.3 and ZEP reports. The economic feasibility analysis is illustrated through a case study with a CO2 transport capacity range of 0.5 to 2.5 mtpa (million tons per annum) and a transport length range of 180 km to 1500 km. The prices of CO2 per ton for the SFG, crew and autonomous tankers, and offshore pipelines are comprehensively compared. According to the results, SFGs with capacities of 469 m3, 1194 m3, and 2430 m3 are technically possible to manufacture. Moreover, the SFGs are competitive with a smaller CO2 capacity of 0.5 mtpa at distances of 180 and 500 km and a capacity of 1 mtpa at a distance of 180 km.
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Fang, Yin-Ying, Chi-Fang Chen y Sheng-Ju Wu. "Feature identification using acoustic signature of Ocean Researcher III (ORIII) of Taiwan". ANZIAM Journal 59 (25 de julio de 2019): C318—C357. http://dx.doi.org/10.21914/anziamj.v59i0.12655.
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Underwater acoustic signature identification has been employed as a technique for detecting underwater vehicles, such as in anti-submarine warfare or harbour security systems. The underwater sound channel, however, has interference due to spatial variations in topography or sea state conditions and temporal variations in water column properties, which cause multipath and scattering in acoustic propagation. Thus, acoustic data quality control can be very challenging. One of challenges for an identification system is how to recognise the same target signature from measurements under different temporal and spatial settings. This paper deals with the above challenges by establishing an identification system composed of feature extraction, classification algorithms, and feature selection with two approaches to recognise the target signature of underwater radiated noise from a research vessel, Ocean Researcher III, with a bottom mounted hydrophone in five cruises in 2016 and 2017. The fundamental frequency and its power spectral density are known as significant features for classification. In feature extraction, we extract the features before deciding which is more significant from the two aforementioned features. The first approach utilises Polynomial Regression (PR) classifiers and feature selection by Taguchi method and analysis of variance under a different combination of factors and levels. The second approach utilises Radial Basis Function Neural Network (RBFNN) selecting the optimised parameters of classifier via genetic algorithm. The real-time classifier of PR model is robust and superior to the RBFNN model in this paper. This suggests that the Automatic Identification System for Vehicles using Acoustic Signature developed here can be carried out by utilising harmonic frequency features extracted from unmasking the frequency bandwidth for ship noises and proves that feature extraction is appropriate for our targets.
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