45 research outputs found

    Research on the Heat Dissipation Characteristics of Lithium Battery Spatial Layout in an AUV

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    To meet the power demand requirements of autonomous underwater vehicles (AUVs), the power supply is generally composed of a large number of high-energy lithium battery groups. The lithium battery heat dissipation properties not only affect the underwater vehicle performance but also bring some security risks. Based on the widespread application of lithium batteries, lithium batteries in an AUV are taken as an example to investigate the heat dissipation characteristics of the lithium battery spatial layout in an AUV. With the aim of increasing the safety of lithium batteries, a model is developed for the heat transfer process based on the energy conservation equation, and the battery heat dissipation characteristics of the spatial layout are analyzed. The results indicate that the most suitable distance between the cells and the cross arrangement is better than the sequence arrangement in terms of cooling characteristics. The temperature gradient and the temperature change inside the cabin with time are primarily affected by the navigation speed, but they have little relationship with the environmental temperature

    Fuel cell systems for marine applications

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    The aim of this work is the assessment of the most suitable hydrogen solution for ship applications and the definition of the role of hydrogen as alternative fuel for shipping. The importance of the \u201cHydrogen Technologies\u201d for ships comes from the most important social challenge that is driving innovation in the shipping sector: Environmental Challenge. The PhD research project encountered important development both from the industrial and the academic side that brought to the construction of a joint laboratory between Fincantieri and the Polytechnic School of the University of Genoa, the: HI-SEA laboratory, dedicated to the study of fuel cell system for marine application. Moreover the simulation modelling and experimental results developed during the PhD research on the PEM fuel cell and MH hydrogen storage systems, found an application in the nautical sector. The former brought to a patent and the creation of a dedicated start-up company named H2Boat, that was recognised as University spin-off. The first part of the study define the role of hydrogen as alternative energy vector (fuel) for marine application, analysing the complex context in which it is supposed to be used. In part 2.1 a detailed assessment of the characteristics of different alternative fuels have been conducted. The complexity of work brought to the construction of comparative models, descripted in part 2.2 that have been used to analyse the characteristic of various alternative solution. An analysis of the PEM FCS state of the art is presented in part 2.3 together with the definition of FCS design for marine application in part 2.4. The study of the hydrogen technologies considered also the definition of simulation models of fuel cell systems and metal hydride hydrogen storage system 3.2. The former has also been assessed towards experimental tests, presented in part 3.3. The models have been used to develop larger laboratory, to define correct operative parameters and FCS design. Finally a number of application developed during the PhD study are proposed in part 4 to show the goal of the research that is still under development

    Final Technical Report For The Enhancement Of Autonomous Marine Vehicle Testing In The South Florida Testing Facility Range

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    The purpose of this grant was to carry out the six scientific experiments on the South Florida Testing Facility (SFTF) Range. In addition to the enhancements to the range, work was performed on all six with some being successfully completed while research continues on the long term tasks

    Scientific challenges and present capabilities in underwater robotic vehicle design and navigation for oceanographic exploration under-ice.

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    This paper reviews the scientific motivation and challenges, development, and use of underwater robotic vehicles designed for use in ice-covered waters, with special attention paid to the navigation systems employed for under-ice deployments. Scientific needs for routine access under fixed and moving ice by underwater robotic vehicles are reviewed in the contexts of geology and geophysics, biology, sea ice and climate, ice shelves, and seafloor mapping. The challenges of under-ice vehicle design and navigation are summarized. The paper reviews all known under-ice robotic vehicles and their associated navigation systems, categorizing them by vehicle type (tethered, untethered, hybrid, and glider) and by the type of ice they were designed for (fixed glacial or sea ice and moving sea ice). © 2020 by the authors

    RRS James Cook Expedition JC237, 6 AUGUST – 4 SEPTEMBER 2022. CLASS – Climate-linked Atlantic Sector Science Whittard Canyon and Porcupine Abyssal Plain Fixed Point Observatories

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    JC237 was one of the main expeditions of the CLASS National Capability programme funded by NERC (UK). Delayed by two years as a result of the COVID-19 pandemic, the expedition combined two important pieces of observational work for the CLASS programme. The main aim of the cruise was to revisit key sites, last surveyed on JC125 in 2015, in the Whittard Canyon system on the Celtic Margin. This submarine canyon, and its protected area (The Canyons Marine Conservation Zone in English waters) is one of the long-term benthic time-series locations of the CLASS programme. The goal of the survey was to increase our understanding of benthic ecosystem change and recovery in the deep sea, under either natural (e.g. sediment flows, flank collapses) or anthropogenic (e.g. bottom trawling) environmental disturbance. Furthermore, the new datasets expand the general knowledge on the geological framework, sediment dynamics, current regimes and habitat distributions in land-detached submarine canyons – important connecting pathways between shelf and deep sea. The second CLASS-related aim was to carry out photographic surveys at the Porcupine Abyssal Plain Sustained Observatory (PAP-SO) – the longest-running deep-water observatory worldwide. Annual observations at this location create an invaluable record. The availability of an ROV (first time for the PAP-SO site) and a deep-water AUV (only second visit) during JC237 opened new opportunities for detailed sampling and extensive imaging of the benthic community. In addition, JC237 also had a technical demonstrator/development component: it was the first science expedition for the brand-new Autosub5 deep-water AUV and for the DeepGlider from MARS (the Marine Autonomous and Robotics Systems division at NOC). Furthermore, the Autosub5 was equipped with the new RoCSI eDNA sampler, enabling in-situ sampling and preservation of eDNA at depths up to 4500m. This demonstrator was part of the iAtlantic project. Overall, the expedition was a great success, with an extensive amount of data and samples collected (15 AUV missions with >250,000 photographs, 700k sidescan & multibeam, 60 RoCSI samples; 17 ROV dives, 45 days of DeepGlider observations, 21 CTD casts, 5 megacores, 12 gravity cores, 4 CPR transects and 10s of km2 of shipboard multibeam data collected). First interpretations have already illustrated coral expansion in some locations in the canyon, while geomorphological change seems limited

    Delivering sustained, coordinated and integrated observations of the Southern Ocean for global impact

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    The Southern Ocean is disproportionately important in its effect on the Earth system, impacting climatic, biogeochemical, and ecological systems, which makes recent observed changes to this system cause for global concern. The enhanced understanding and improvements in predictive skill needed for understanding and projecting future states of the Southern Ocean require sustained observations. Over the last decade, the Southern Ocean Observing System (SOOS) has established networks for enhancing regional coordination and research community groups to advance development of observing system capabilities. These networks support delivery of the SOOS 20-year vision, which is to develop a circumpolar system that ensures time series of key variables, and delivers the greatest impact from data to all key end-users. Although the Southern Ocean remains one of the least-observed ocean regions, enhanced international coordination and advances in autonomous platforms have resulted in progress toward sustained observations of this region. Since 2009, the Southern Ocean community has deployed over 5700 observational platforms south of 40°S. Large-scale, multi-year or sustained, multidisciplinary efforts have been supported and are now delivering observations of essential variables at space and time scales that enable assessment of changes being observed in Southern Ocean systems. The improved observational coverage, however, is predominantly for the open ocean, encompasses the summer, consists of primarily physical oceanographic variables, and covers surface to 2000 m. Significant gaps remain in observations of the ice-impacted ocean, the sea ice, depths >2000 m, the air-ocean-ice interface, biogeochemical and biological variables, and for seasons other than summer. Addressing these data gaps in a sustained way requires parallel advances in coordination networks, cyberinfrastructure and data management tools, observational platform and sensor technology, two-way platform interrogation and data-transmission technologies, modeling frameworks, intercalibration experiments, and development of internationally agreed sampling standards and requirements of key variables. This paper presents a community statement on the major scientific and observational progress of the last decade, and importantly, an assessment of key priorities for the coming decade, toward achieving the SOOS vision and delivering essential data to all end-users.Fil: Newman, Louise. University of Tasmania; AustraliaFil: Heil, Petra. Australian Antarctic Division; Australia. Antarctic Climate And Ecosystems Cooperative Research Centre; AustraliaFil: Trebilco, Rowan. Australian Antarctic Division; Australia. Antarctic Climate And Ecosystems Cooperative Research Centre; AustraliaFil: Katsumata, Katsuro. Japan Agency For Marine earth Science And Technology; JapónFil: Constable, Andrew J.. Antarctic Climate And Ecosystems Cooperative Research Centre; Australia. Australian Antarctic Division; AustraliaFil: Wijk, Esmee van. Commonwealth Scientific And Industrial Research Organization; Australia. Antarctic Climate And Ecosystems Cooperative Research Centre; AustraliaFil: Assmann, Karen. University Goteborg; SueciaFil: Beja, Joana. British Oceanographic Data Centre; AustraliaFil: Bricher, Phillippa. University of Tasmania; AustraliaFil: Coleman, Richard. University of Tasmania; AustraliaFil: Costa, Daniel. University of California; Estados UnidosFil: Diggs, Steve. University of California; Estados UnidosFil: Farneti, Riccardo. The Abdus Salam; Italia. The Abdus Salam. International Centre for Theoretical Physics; ItaliaFil: Fawcett, Sarah. University of Cape Town; SudáfricaFil: Gille, Sarah. University of California; Estados UnidosFil: Hendry, Katharine R.. University of Bristol; Reino UnidoFil: Henley, Sian F.. University of Edinburgh; Reino UnidoFil: Hofmann, Eileen. Old Dominion University; Estados UnidosFil: Maksym, Ted. University of California; Estados UnidosFil: Mazloff, Matthew. University of California; Estados UnidosFil: Meijers, Andrew J.. British Antartic Survey; Reino UnidoFil: Meredith, Michael. British Antartic Survey; Reino UnidoFil: Moreau, Sebastien. Norwegian Polar Institute; NoruegaFil: Ozsoy, Burcu. Istanbul Teknik Üniversitesi; TurquíaFil: Robertson, Robin. Xiamen University; ChinaFil: Schloss, Irene Ruth. Universidad Nacional de Tierra del Fuego; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Schofield, Oscar. State University of New Jersey; Estados UnidosFil: Shi, Jiuxin. Ocean University Of China; ChinaFil: Sikes, Elisabeth L.. State University of New Jersey; Estados UnidosFil: Smith, Inga J.. University of Otago; Nueva Zeland

    Summary of Research 1994

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    The views expressed in this report are those of the authors and do not reflect the official policy or position of the Department of Defense or the U.S. Government.This report contains 359 summaries of research projects which were carried out under funding of the Naval Postgraduate School Research Program. A list of recent publications is also included which consists of conference presentations and publications, books, contributions to books, published journal papers, and technical reports. The research was conducted in the areas of Aeronautics and Astronautics, Computer Science, Electrical and Computer Engineering, Mathematics, Mechanical Engineering, Meteorology, National Security Affairs, Oceanography, Operations Research, Physics, and Systems Management. This also includes research by the Command, Control and Communications (C3) Academic Group, Electronic Warfare Academic Group, Space Systems Academic Group, and the Undersea Warfare Academic Group
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