Date of Award

7-2018

Document Type

Dissertation - Open Access

Degree Name

Doctor of Philosophy in Mechanical Engineering

Department

Mechanical Engineering

Committee Chair

Eric J. Coyle, Ph.D.

First Committee Member

Brian K. Butka, Ph.D.

Second Committee Member

Patrick N. Currier, Ph.D.

Third Committee Member

Charles F. Reinholtz, Ph.D.

Abstract

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.

Share

COinS