Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 2000. / Includes bibliographical references (leaf 66). / Model testing to date has not incorporated the simulation of realistic propulsion in the testing of closed loop control of ships. The development of a DDG-51 hull model for these tests is described, and the preliminary data from the sensor suite to be used for feedback control is analyzed. Based on the short duration of tests, the angular rate sensors are relied upon to correct for gravitational contributions in pitch while stabilized roll is used for sway correction. Signal noise, integration errors and sensor drift are bandpass filtered out in selected sensor channels. The preliminary results of double integrated position in global coordinates correlate well with experimental observations, and recommendations for continued development of the ship model are made. / by Albert Wu. / S.M.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 2000. / Includes bibliographical references (leaves 84-86). / In this thesis, I designed and tested a supervisory control scheme for the Odyssey II-class Autonomous Underwater Vehicles that relies on a very-low-data-rate acoustic communication link. A human supervisor communicates with the AUV over a combination radio/acoustic network. The supervisor radios commands from shore to data repeater nodes moored at strategic locations on the ocean surface. Utility Acoustic Modems mounted on the moorings rebroadcast the binary data into the sea in the 12-17 kHz frequency band. The moving AUV detects the transmission, decodes the message, and carries out the command contained within. The operator's commands are implemented in the context of a behavior-based layered control software architecture. The supervisory control scheme was tested and verified during the Synaptic Internal Tide Experiment, which took place in Monterey Bay during August and September, 1999. / by William Ryan Kreamer. / S.M.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1997. / Includes bibliographical references (p. 155-160). / by Sean Patrick McKenna. / M.S.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1999. / Includes bibliographical references (leaves 118-119). / by Chin-Swee Chia. / S.M.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 2002. / Includes bibliographical references (leaves 133-136). / A method for coupling a Reynolds-averaged Navier-Stokes (RANS) computer code with an inviscid panel code to predict the maneuvering characteristics of submarines operating near the free-surface has been developed. The RANS code calculates the flow field immediately surrounding and in the wake of the body where viscous effects are important. The panel code calculates the fluid flow in the far field including the free-surface where viscous effects are negligible. The computational domains used by each code overlap, and it is this overlap that enables their coupling. The evolution of the free-surface boundary condition is linked to the evolution of the bulk flow through a novel iteration technique that first computes the viscous flow near and in the wake of the body, and then computes the potential flow outside the viscous region including at the free-surface. Calculated and measured vertical force and pitching moment are in excellent agreement for conditions where free-surface effects are minimal. In addition calculated vertical plane maneuvering coefficients are presented. There is no known experimental force and moment data available for submarine bodies where free-surface effects are significant, and therefore only qualitative statements pertaining to validation of the method can be made under such conditions. Five submarine geometries operating at five depths, seven Froude numbers and several pitch angles have been simulated to obtain relationships between these parameters and the vertical force and pitching moment on the bodies. Iterative and grid convergence have been demonstrated. / by Michael J. Griffin. / Ph.D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 2001. / Includes bibliographical references (leaves 122-126). / Recently, waterjet propulsion has gained great commercial interest as the shipping industry trends toward faster passenger ferries and other fast transport vessels. The work presented in this thesis was part of a larger effort to improve the capabilities and performance of a mixed flow marine waterjet used in such high speed marine applications. An experimental test faciity was constructed and employed in the testing of a mixed flow marine waterjet rotor, stator and housing set. Full description of the facility and waterjet test procedures are discussed. The pumpset was designed using a coupled Lifting Surface/RANS procedure by Taylor et.al.[35] and was built and tested as part of the work presented in this research. Detailed measurements of the pump performance is described including pump curves, tipgap studies, inlet, midstage and outlet velocity and pressure profiles in an axisymmetric inflow. Full accounting for losses including rotor and stator loss profiles as well as a full pumpset energy balance is presented. From the results of the experiment, dominant losses were found near the tip/duct junction casing along with a large and unexpected increase in swirl in this region. Detailed numerical modelling of this pumpset was performed using both a Lifting Surface/RANS procedure and a Lifting Surface/Euler solver. Effects of losses were modelled as well as tipgap effects. Prior work had developed these coupling procedures but the computationally efficient Euler coupling lacked the introduction of loss and drag induced swirl. This loss coupling was added to the model and the analysys results are discussed. Also, a model to align the wakesheet with the local flowfield in the Lifting Surface solver was developed and these results are discussed. / by Richard Warren Kimball. / Ph.D.

Thesis (S.M. in Naval Architecture and Marine Engineering)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 2001. / Includes bibliographical references (leaves 97-99). / by Caspar Andri Largiadèr. / S.M.in Naval Architecture and Marine Engineering

Thesis (Ocean. E.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1994. / Includes bibliographical references (leaves 74-76). / by Gökhan Göktuğ. / Ocean.E.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1994. / Includes bibliographical references (p. 42-43). / by Aria Landstrom. / M.S.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1995. / Includes bibliographical references (p. 87-89). / by Roberto E. Soto. / M.S.