Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1998. / Includes bibliographical references (leaves 132-137). / by Sungeun Kim. / Ph.D.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 2004. / Includes bibliographical references (leaves 115-119). / On June 5, 1920, the Merchant Marine Act of 1920, also known as the Jones Act, became law. The Jones Act, a cabotage law, restricts American waterborne domestic trade to vessels flagged in the United States, owned by citizens of the United States, operated by citizens of the United States, and built in the United States. This highly restrictive law has become an integral part of American maritime policy. A brief history of the maritime policies of the United States and the Merchant Marine Act of 1920 is followed by an evaluation of the effects of the act on the maritime and shipbuilding industries, an evaluation of the effects on the American economy, and an evaluation of the political debate surrounding the act. Conclusions are made regarding the effects of the act and recommendations are made for the future of the act. / by Richard A. Smith. / S.M.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 2001. / Includes bibliographical references (p. 267-275). / This dissertation extends the use of the dynamic stiffness and transfer matrix methods in marine riser vibration. Marine risers possess a predominant chain topology. The transfer matrix method is appropriate for the analysis of such structures. Wave transmission and reflection matrices are formulated in terms of transfer-matrix elements. The delta-matrix method is introduced to deal with numerical problems associated with very long beams and high frequencies. The general internal relationships between the transfer matrix and dynamic stiffness methods are derived and applied to the problem of a non-uniform beam with discontinuities. An implicit transfer matrix of a general non-uniform beam is derived. The vibration analysis of non-uniform marine risers is addressed by combining the procedure of the dynamic stiffness method with the WKB theory. The WKB-based dynamic stiffness matrix is derived and the frequency-dependent shape function is expressed implicitly. The Wittrick-Williams algorithm is extended to the analysis of a general non-uniform marine riser, allowing automatic computation of natural frequencies. Marine riser models with complex boundary conditions are analyzed. The WKB-based dynamic stiffness method is improved and applied to a non-uniform beam system with discontinuities. A dynamic stiffness library is created. Dynamic vibration absorbers and wave-absorbing terminations are investigated as a means of suppressing vibration. The optimal tuning of multiple absorbers to a non-uniform beam system under varying tension is investigated. The properties of wave-absorbing terminations of a beam system are derived. The vibration of two concentric cylinders coupled by the annulus fluid and by periodic centralizers is modeled. The effects of coupling factors on vibration are numerically evaluated. It is shown that a properly designed inner tubular member may be used to damp the flow-induced vibration of the outer cylinder. / by Weigang Chen. / Ph.D.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 2002. / Includes bibliographical references (leaves 56-59). / by Alexandros Gorgias. / S.M.

Thesis (Ocean E.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1995. / Includes bibliographical references (leaves 80-81). / by Platon Michael Velonias. / Ocean E.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1990. / Includes bibliographical references (leaves 241-247). / by Chirdpun Vitooraporn. / Ph.D.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 2004. / Includes bibliographical references (leaf 132). / The purpose of this thesis is to expand and analyze the decisions that are constantly being made by shipping companies concerning acquisition of newbuildings, the construction of newbuildings, operational aspects as well as financial issues concerning a shipping company. The issues that shall be analyzed and discussed have been deduced after extended discussions with technical directors of some of the major Greek Shipping Companies. Once all issues at hand have been deduced, this thesis shall provide a general introduction, and consequently an analysis of each and every major event at hand, indicating Shipping Company's various options. The next step shall be to analyze the results of all the interviews, and then finally give further comments and suggestions concerning each and every major event at hand shall be indicated. / by Vasileios Maroulis. / S.M.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1998. / Includes bibliographical references (leaf 91). / The U.S. Navy has changed many of its acquisition practices. One of these changes is from performing the early design work primarily in-house, to contracting private shipyards to do the design. This change has shifted the government's role in design to a predominantly review function. Therefore, the government needs to decide what level of review should be performed, and how much this will cost in the future. This research examines the Strategic Sealift acquisition program, which was one of the first programs that employed this new acquisition strategy. The costs of the design stages are identified, and the level of review is described. This research can be compared to later programs, and possibly used as a benchmark for future programs. / by Andrew T. Speirs. / S.M.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 2001. / Includes bibliographical references (leaves 129-132). / One of the main problem affecting modern propulsor design engineers is the ability to quantitatively predict unsteady propeller forces for modern, multi-blade row, ducted propulsors operating in highly contracting flowfields. Current algorithms provide valuable insight into qualitative trendlines for these modern designs. This thesis has focused on the more accurate quantitative force prediction by introducing more physical modeling into the numerical computations, using more accurate analytical representation of continuous physical phenomena, whilst not increasing the usage complexity for the desktop engineer. This thesis developed several novel algorithms and techniques and applied them to build an evolutionary, general vortex-lattice lifting-surface propeller code. First, a general method to track the trajectory of individual wake singularity sheets and compute their influence velocities was evolved which reduces computation time, and dramatically increases the accuracy of the unsteady blade loading problem. To improve the general coupling technique between potential-based propeller codes and volumetric Reynolds-Averaged Navier-Stokes codes, a general analytic method based upon an elliptic integral method for the velocity induced by a vortex ring of unsteady harmonic strength to compute of the time-averaged induced velocities in the swept volume of the propeller was introduced which is more accurate, as demonstrated in model problems, and more robust, as indicated by improved convergence and accuracy in a fully three dimensional propeller code. / (cont.) A discretized geometric technique was also created to internalize the coupling routines, making the code more robust, while decreasing the computation burden over currect methods. Finally, a higher order quadratic influence function technique was implemented within the wake to more accurately define the induction velocity at the trailing edge which has suffered in the past due to lack of discretization. These propeller propgram enhancements were fitted into a fully functional version of the Propeller Unsteady Forces (PUF)-series code, and coupled with a three dimensional RANS code. / Ph.D.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1991. / Includes bibliographical references (leaves 140-146). / by Ravikumar Ramiah Nagabushanam. / M.S.