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

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

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

Design, construction, and operation of an unmanned underwater vehicle

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2009.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Includes bibliographical references (leaf [62]).The practical usage of unmanned underwater vehicles (UUVs) is limited by vehicle and operation cost, difficulty in accurate navigation, and communication between the vehicle and operator. The "Rex 2" UUV employs a system design where a submersible is connected to a float at the water's surface by means of a tether. By maintaining a surface expression, high-bandwidth radio communication to the operator becomes possible, and GPS may be used for accurate navigation. This arrangement allows the freedom of movement characteristic of untethered autonomous underwater vehicles (AUVs), while maintaining the live operator control and communication found with tethered remotely operated vehicles (ROVs). Expanding on the design and field experiences with the MIT AUV Lab's first Reef Explorer UUV, Rex 2 was designed to be inexpensive, easy to deploy, adaptable to various payloads, and simple to use. Rex 2 was designed, built, and operated in a number of ocean field tests, validating the utility of the vehicle and system concept.by Dylan Owens.S.M

Hydromodus: An Autonomous Underwater Vehicle

Hydromodus is a student-led multidisciplinary project conceived by Jordan Read designed to provide a low-cost modular hardware and software solution for researchers and scientists. For the scope of the Senior Project class, it is designed to be a baited remote underwater vehicle (BRUV), but the platform is highly modifiable and open-source

Underwater Vehicles

For the latest twenty to thirty years, a significant number of AUVs has been created for the solving of wide spectrum of scientific and applied tasks of ocean development and research. For the short time period the AUVs have shown the efficiency at performance of complex search and inspection works and opened a number of new important applications. Initially the information about AUVs had mainly review-advertising character but now more attention is paid to practical achievements, problems and systems technologies. AUVs are losing their prototype status and have become a fully operational, reliable and effective tool and modern multi-purpose AUVs represent the new class of underwater robotic objects with inherent tasks and practical applications, particular features of technology, systems structure and functional properties

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

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

Modular high maneuverability autonomous underwater vehicle

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2009.Includes bibliographical references (p. 111-115).The design and construction of a modular test bed autonomous underwater vehicle (AUV) is analyzed. Although a relatively common stacked-hull design is used, the state of the art is advanced through an aggressive power plant, with capability to support azimuthing thrusters and a 2DOF front sensor assembly. Through an application of lean principles to developmental hardware, the notion of a delayed differentiation is isolated as a key to minimizing rework and creating essentially transparent electronic hardware. Additionally, the use of bus-modular structural and electronic interconnects facilitates reconfiguration of the vehicle across a large range of components, allowing the rapid development of new sensors, control algorithms, and mechanical hardware. Initial wet tests confirm basic data acquisition capabilities and allowed sensor fusion of scanning sonar returns at the beam level with data from an IMU for an orientation-corrected sonar mosaic.by Daniel G. Walker.S.M