Improving Seaglider Efficiency: An Analysis of Wing Shapes, Hull Morphologies, and Propulsion Methods

Autonomous underwater gliders are a family of autonomous underwater vehicles used for long-term observation of oceanic environments. These gliders leverage changes in buoyancy and the resulting vertical motion, to generate forward locomotion via hydrodynamic surfaces. In order to function for extended periods, these systems operate in a low-speed, low-drag regime. This research examines factors impacting the operational efficiencies of gliders, including morphological changes, configuration changes, and propulsion. An interesting question arises when considering the operational efficiencies of conventionally propelled systems at the operating speeds typical of gliders. Can a conventional propulsion system match the efficiency of an underwater glider buoyancy engine? A first-principles, energy-based approach to glider operations was derived and verified using real world data. The energy usage for buoyancy driven propulsion was then compared to conventional propulsion types. The results from these calculations indicate that a conventionally propelled autonomous underwater vehicle can compete with and in some cases outperform a buoyancy driven system given the proper propulsive efficiency

Developing an underwater glider for educational purposes

Buoyancy-driven underwater gliders (UGs) have proven to be quite effective for long-range, long-term oceanographic sampling. However, current off-the-shelf UGs are large, heavy, expensive, and difficult to modify, both in hardware and software, which prevents their frequent use for lake observations and limits researchers\u27 ability to perform multi-vehicle coordination experiments. Our current research goal is to develop UGs that would share the buoyancy-driven concept with the first generation of gliders, but are smaller in size, lighter in weight, and lower in price. Our future research goal is to design and develop an underwater glider fleet that will result in novel and transformative research capabilities in coordinated control. Along with advancing research and broadening data collection ability, UGs provide a hands-on tool for engaging students in sophisticated STEM learning. This paper describes in detail the design, manufacturing, and modeling of our inexpensive Glider for Underwater Problem-solving and Presentation in Education (GUPPIE). GUPPIE was developed using practical components such as syringes for buoyancy control and a hull made of acrylic for easy analysis. The design is both affordable and easy-to-duplicate. GUPPIE\u27s pedagogical platform provides hands-on learning applications that demonstrate glider mechanics, mechatronics, hydrodynamics, trimming, diving and surfacing performance, and mobility in water. © 2013 IEEE