Thesis (M.S. in Naval Architecture and Marine Engineering and M.S. in Civil and Environmental Engineering)--Massachusetts Institute of Technology, 2002. / Includes bibliographical references (leaves 64-65). Also available online.

Thesis: M.S., Massachusetts Institute of Technology, Department of Ocean Engineering, 1977 / Bibliography : leaves 166-167. / M.S. / M.S. Massachusetts Institute of Technology, Department of Ocean Engineering

CIVINS / The United States Navy has taken a new interest in tumblehome hulls. While the stealth characteristics of these hull forms make them attractive to the Navy, their sea keeping characteristics have proven to be problematic. Normal approximations of sea keeping characteristics using linear differential equations with constant coefficients predict a very stable platform, while observations in model tests show a ship that is prone to extreme roll transients. This thesis examines a simple method of producing a non-linear simulation of roll motion using a tumblehome hull provided by the Office of Naval Research. This research demonstrates the significant difference that a variable restoring coefficient introduces into a hull's seakeeping characteristics. / Contract number: N62271-97-G-0026 / CIVINS

Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1979. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Bibliography: leaves 67-68. / by M. Bradham Brewster. / B.S.

Thesis (Nav.Arch)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1975. / Bibliography: leaves 152-157. / Nav.Arch

This thesis looks at how the GPU¡¦s processing of objects can be simplified (from the programmer¡¦s point of view) and improved (from the run-time point of view). We propose both software and hardware modifications for automatic occlusion detection to avoid rendering occluded objects. We also consider subobjects. The method takes advantage of partial occlusion opportunities and also allow for parts of an object to self-occlude other parts of the same object. Their rendering sequence can be dynamically reordered at minimal cost, thereby increasing the self-occlusion opportunities within the object. In addition, this thesis investigates methods of automatic hull creation and subobject creation.

Ship-shaped hulls have often been found to be subject to excessive roll motions, and therefore, inhibit their use as a stable production platform. To solve the problem, bilge keels have been widely adopted as an effective and economic way to mitigate roll motions, and their effectiveness lies in their ability to damp out roll motions over a range of frequencies. In light of this, the present research focuses on roll motions of shipshaped hulls. A finite volume method based two-dimensional Navier-Stokes solver is developed and further extended into three dimensions. The present numerical scheme is implemented for modeling the flow around ship-shaped hulls in roll motions and for predicting the corresponding hydrodynamic loads. Also conducted are studies on the hydrodynamic performance of ship-shaped hull sections in prescribed roll motions and in transient decay motions. Systematic studies of the grid resolutions and the effects of free surface, hull geometries and amplitude of roll angle are performed. Predictions from the present method compare well to those of other methods, as well as to measurements from experiments. Non-linear effects, due to flow viscosity, were observed in small as well as in large roll amplitudes, particularly in the cases of hulls with sharp corners. The study also shows that it is inadequate to use a linear combination of added-mass and damping coefficients to represent the corresponding hydrodynamic loads. As a result, it also makes the calculation of the hull response in time domain inevitable. Finally, the capability of the present numerical scheme to apply to fully three-dimensional ship motion simulations is demonstrated. / text

This thesis is based on an industry project with Teekay Shipping Co ., which is an international transportation service provider for oil companies, refiners and traders. Teekay is interested in knowing which factors contribute most to its operating incidents and accidents. Based on available data, namely vessel name, team, type, hull, and age, as well as incident and accident records, we quantified in this thesis the effects of these factors on the incident and accident frequency. The thesis presented the technical details of the Poisson regression analysis, which we used for quantifying the risk factors. Teekay is also interested in having a consistent method to present Teekay's overall risk picture, and to indicate best investment areas for its risk reducing purpose. Teekay has already implemented an Online Root Cause Analyses (ORCA) system, which collects the direct cause and root cause soon after an incident happens. We reviewed the ORCA system and made suggestions about certain parts of the system which were subsequently revised. Furthermore, we designed a bubble chart tool to present the overall risk faced by Teekay. The bubble chart tool has the capacity to indicate best investment areas clearly, and it is consistent over time, thereby enabling Teekay to evaluate easily the risk mitigation effect of its earlier investment in risk management. Finally, we designed a continuous monitoring tool, which allows Teekay managers to interactively explore the relationships among near misses, incidents and accidents, and to compare event frequencies of various vessel groups, such as vessel team, age, type and hull structure. The powerful continuous monitoring tool provides Teekay managers a full- range view of the risks the company faces. The design and the sample usage of this continuous monitoring tool are discussed in this thesis.

Thesis(M.S.)--Auburn University, 2005. / Abstract. Includes bibliographic references.

Thesis (Ph. D.)--University of Texas at Austin, 2008. / Vita. Includes bibliographical references.