Thesis (Nav. E.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1994, and Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1994. / Includes bibliographical references (leaves 145-147). / by Gregory Robert Thomas. / M.S. / Nav.E.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering; and, (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2001. / Includes bibliographical references (leaf 89). / It is estimated that 70 to 85 percent of a naval ship's life-cycle cost is determined during the concept exploration phase which places an importance in the methodology used by the designer to select the concept design. But trade-off studies are guided primarily by past experience, rules-of-thumb, and designer preference. This approach is ad hoc, not efficient and may not lead to an optimum concept design. Even worse, once the designer has a "good" concept design, he has no process or methodology to determine whether a better concept design is possible or not. A methodology is required to search the design space for an optimal solution based on the specified preferences from the customer. But the difficultly is the design space, which is non-linear, discontinuous, and bounded by a variety of constraints, goals, and thresholds. Then the design process itself is difficult to optimize because of the coupling among decomposed engineering disciplines and sub-system interactions. These attributes prevent application of mature optimization techniques including Lagrange multipliers, steepest ascent methods, linear programming, non-linear programming, and dynamic programming. To further improve submarine concept exploration, this thesis examines a statistical technique called Response Surface Methods (RSM). The purpose of RSM is to lead to an understanding of the relationship between the input (factors) and output (response) variables, often to further the optimization of the underlying process. The RSM approach allows the designers to find a local optimal and examine how the design factors affect the response in the region around the generated optimal point. RSM can be applied to submarine concept exploration and provide a methodology to: determine the optimal concept design based on customer preference, efficiently perform trade-off studies, determine the feasible design space, and the ability to determine in advance if a specified concept design is feasible and meets all the customer thresholds and constraints. / by David A. Goggins. / S.M.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1997, and Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1997. / Includes bibliographical references (leaves 123-124). / by James Taylor Czarnowski. / M.S.

Thesis (Nav. E.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1997, and Thesis (M. Eng)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1997. / Includes bibliographical references (leaves 104-107). / by Christopher S. Trost. / M.Eng / Nav.E.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1997, and Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1997. / Includes bibliographical references (p. 229-236). / by Hideki Shimizu. / M.S.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering; and, (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2004. / Includes bibliographical references (leaves 88-89). / The Lagrange multiplier theorem and optimal control theory are applied to a continuous shape optimization problem for reducing the wave resistance of a submerged body translating at a steady forward velocity well below a free surface. In the latter approach, when the constraint formed by the boundary conditions and the Laplace's governing equation is adjoined to the objective functional to construct the Lagrangian, the dependence of the state on the control is disconnected and they are treated as independent variables; whereas in the first approach, dependences are preserved for the application of Lagrange multiplier theorem. Both methods are observed to yield identical solutions and adjoint equations. Two alternative ways are considered for determining the variation of the objective functional with respect to the state variable which is required to solve the adjoint equation defined on the body boundary. Comparison of these two ways also revealed identical solutions. Finally, a free surface boundary is included in the optimization problem and its effect on the submerged body shape optimization problem is considered. / (cont.) Noting that the analytical solution to the local optimization problem holds for any initial body geometry, it is therefore concluded that the above study will provide theoretical background for an efficient hydrodynamic shape optimization module to be coupled with up-to-date flow solvers currently available such as SWAN. / by Onur Geçer. / S.M.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering; and, (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2005. / Includes bibliographical references (leaves 87-88). / Field studies have demonstrated that the Non-Intrusive Load monitor (NILM) can provide real-time indication of the condition of electro-mechanical systems on board naval vessels. Results from data collected from engineering systems on board USCGC SENECA (WMEC-906), a 270-foot U.S. Coast Guard cutter, indicate that the NILM can effectively identify faults, failures and deviations from normal operating conditions on numerous shipboard engineering systems. Data collected from the sewage system identified metrics that can be applied, for example, to cycling systems (high pressure air, hydraulic systems, etc.) to differentiate between periods of heavy usage and fault conditions. Sewage system variability and randomness was minimized by employing a MATLAB simulation designed to permit exploration of system behavior that might not have been exposed during other conditions. Simulation data suggests that the presence, location and magnitude of a spike in the pump run distribution indicated the presence of a leak. Data from the actual shipboard system, when subjected to a quantifiable leak, displayed the same behavior. Data collected from the Auxiliary Seawater (ASW) System indicated that the NILM is able to predict the failure of a flexible coupling linking the pump and motor components. / (cont.) The ASW motor-pump system was modeled using a 5th order induction motor simulation to explore the electro-mechanical relationships between the motor, coupling and pump. Changes to the mechanical parameters of the coupling were captured in the electrical signature of the motor in both the simulation and shipboard data. Frequency domain analysis of the ASW System data also suggested that the clogging of a heat exchanger on a critical shipboard system can be identified with the NILM, although the extent of diagnosis is dependent on the system flow patterns. Further development of hardware and software, along with continued research into the behavior of shipboard systems, will allow the NILM to augment existing monitoring systems and potentially serve as a stand-alone indicator of critical system performance. / by Thomas W. DeNucci. / S.M.

Thesis (Nav. E.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1989 and Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1989. / Title as it appears in the M.I.T. Graduate List, June 1989: A cooling motion apparatus for hydrodynamic model testing in a non-planar cross-flow. / Includes bibliographical references (leaves 80-81). / by David Craig Johnson. / M.S. / Nav.E.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering; and, (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2000. / Includes bibliographical references (leaves 38-40). / by Peter W. Gooding. / S.M.

Thesis (Nav.E.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering; and, (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2002. / Includes bibliographical references (p. 60). / by Shelly L. Price. / Nav.E. / S.M.