Thesis (M.S. in Mechanical Engineering) Naval Postgraduate School, June 2000. / Thesis advisor, Healey, Anthony J. "June 2000." Includes bibliographical references (p. 83). Also available in print.

Thesis (Master of Engineering in Mechanical Engineering)--Cape Peninsula University of Technology, 2018. / Underwater glider wings are the lifting surfaces of unmanned underwater vehicles UUVs depending on the chosen aerofoil sections. The efficiency as well as the performance of an underwater glider mostly depends on the hydrodynamic characteristics such as lift, drag, lift to drag ratio, etc of the wings. Among other factors, the geometric properties of the glider wing are also crucial to underwater glider performance. This study presents an opportunity for the numerical investigation to improve the hydrodynamic performance by incorporating curvature at the trailing edge of a wing as oppose to the standard straight or sharp trailing edge. A CAD model with straight leading edge and trailing edge was prepared with NACA 0016 using SolidWorks 2017. The operating conditions were setup such that the inlet speed varies from 0.1 to 0.5 m/s representing a Reynolds number 27.8 x 10ᵌ and 53 x 10ᵌ. The static pressure at different angles of attack (AOA) which varies from 2 to 16degrees at the increment of 2degrees for three turbulent models (K-Ԑ-standard, K-Ԑ-RNG and K-Ԑ-Realizable), was computed for upper and lower surfaces of the modified wing model using ANSYS Fluent 18.1. Thereafter the static pressure distribution, lift coefficient, drag coefficient, lift to drag ratio and pressure coefficient for both upper and lower surfaces were analysed. The findings showed that the lift and drag coefficient are influenced by the AOA and the inlet speed. If these parameters change the performance of the underwater glider changes as depicted by figure 5.6 and figure 5.7. The hydrodynamics of the underwater glider wing is optimized using the Cʟ/Cᴅ ratio as function of the operating conditions (AOA and the inlet speed). The investigation showed that the optimal design point of the AOA of 12 degrees and a corresponding inlet speed of 0.26m/s. The critical AOA matched with the optimal design point AOA of 12 degrees. It was also observed that Cp varies across the wing span. The results showed the Cp is higher closer to the fuselage while decreasing towards the mid-span and at the tip of the wing. This showed that the wing experiences more stress close to the fuselage than the rest of the wing span which implies that a higher structural rigidity is required close to the fuselage. The results of the drag and lift curves correspond to the wing characteristics typical observed for this type of aerofoil.

Acoustic modems are the basis for emerging undersea wireless communications networks. US Navy Seaweb technology offers an opportunity to perform undersea navigation and tracking by virtue of node-to-node ranging measurements acquired as a by-product of the acoustic communications protocol. A simple localization algorithm is developed and verified with synthetic data and is then tested with an Unmanned Undersea Vehicle (UUV) during an experiment at sea.

Thesis (M.S. in Engineering Acoustics)--Naval Postgraduate School, December 2003. / Thesis advisor(s): Thomas J. Hofler, Joseph A. Rice. Includes bibliographical references (p. 53-54). Also available online.

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Thesis (Ph. D.)--Joint Program in Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Dept. of Ocean Engineering; and the Woods Hole Oceanographic Institution), 2005. / Includes bibliographical references (p. 173-187).

Thesis (M.S. in Electrical Engineering and M.S. in Engineering Acoustics) Naval Postgraduate School, December 1996. / Thesis advisor(s): Monique P. Fargues and Ralph Hippenstiel. "December 1996." Includes bibliographical references (p. 99-101). Also available online.

Thesis (M.S. in Engineering Acoustics)--Naval Postgraduate School, June 2005. / Thesis Advisor(s): Joseph A. Rice, Joseph A. Rice. Includes bibliographical references (p. 47). Also available online.

The zooplankton communities off the north east coast of Scotland, Wee Bankie sand-banks, were studied with traditional net samples and for the first time, for this area, with acoustic methods. A series of zooplankton samples were collected during June 2010 and March/June 2011 together with a set of physical parameters of the water column. Taxonomic analysis of the collected samples enabled the characterisation of zooplankton communities. Neritic communities with oceanic influence were found along the north east coast of Scotland and over the Wee Bankie with spatial variability associated with higher densities of zooplankton inshore. Temporal variability was associated with the expected succession of dominant copepods from spring to summer. An appropriate scattering model, Distorted Wave Born Approximation, was used to predict the target strength of the major zooplanktonic groups and so solve the forward problem to verify a plankton separation algorithm. The algorithm isolated weak scattering targets of zooplankton using three frequencies (38, 120 and 200 kHz) and was used to study the zooplankton spatial distribution during June 2008-2011 in relation to the physical characteristics of the water column. Model predicted target strength for the major zooplanktonic groups was sensitive to orientation for large organisms and material properties for both copepods and euphausiids. The Wee Bankie waters were thermally stratified, with June 2011 the least stratified of all years. Depths of observed maximum backscatter varied in relation to the pycnocline depth and tended to be deeper in offshore stations. The estimated biomass from the observed backscatter increased from 2008 to 2011 but spatial patterns varied from year to year. Although, estimated biomass across years reduced with increasing maximum fluorescence and surface to bottom temperature difference, the same relationship was not evident within year.

published_or_final_version / Physics / Doctoral / Doctor of Philosophy