Thesis: S.M., Massachusetts Institute of Technology, Engineering Systems Division, 2014. / Thesis: Nav. E., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2014. / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 163-164). / Modern Naval Architects use a variety of computer design tools to explore feasible options for clean sheet ship designs. Under the Naval Sea Systems Command (NAVSEA), the Naval Surface Warfare Center, Carderock Division (NSWCCD) has created computer tools for ship design and analysis purposes. This paper presents an overview of some of these tools, specifically the Advanced Ship and Submarine Evaluation Tool (ASSET) version 6.3 and the Integrated Hull Design Environment (IHDE). This paper provides a detailed explanation of a ship design using these advanced tools and presents methods for optimizing the performance of the hullform, the selection of engines for fuel efficiency, and the loading of engines for fuel efficiency. The detailed ship design explores the design space given a set of specific requirements for a cruiser-type naval vessel. The hullform optimization technique reduces a ships residual resistance by using both ASSET and IHDE in a Design of Experiments (DoE) approach to reaching an optimum solution. The paper will provide a detailed example resulting in a 12% reduction in total ship drag by implementing this technique on a previously designed hullform. The reduction of drag results in a proportional reduction in the amount of fuel used to push the ship through the water. The engine selection optimization technique uses MATLAB to calculate the ideal engines to use for fuel minimization. For a given speed-time or power-time profile, the code will evaluate hundreds of combinations of engines and provide the optimum engine combination and engine loading for minimizing the total fuel consumption. This optimization has the potential to reduce fuel consumption of current naval warships by upwards of 30%. / by Adam T. Jones. / S.M. / Nav. E.

Thesis (Nav. E.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering; and, (S.M. in Engineering and Management)--Massachusetts Institute of Technology, Engineering Systems Division, 2010. / Paged in Arabic numerals except p. 1-8 and p. 89-90, which are in Roman numerals. Cataloged from PDF version of thesis. / Includes bibliographical references (p. lxxxix (89)-xc (90)). / Alternative methods for cost estimation are important in the early conceptual stages of a design when there is not enough detail to allow for a traditional quantity takeoff estimate to be performed. Much of the budgeting process takes place during the early stages of a design and it is important to be able to develop a budget quality estimate so a design is allocated the necessary resources to meet stakeholder requirements. Accurate project cost estimates early in the planning and design processes can also serve as a cost-control measure to assist in managing the design process. With an understanding of the most significant engineering decisions that affect project costs, project team members and stakeholders can proactively make cost-effective decisions during the design process rather than after construction begins and it is too late to prevent going over budget. This research examines the potential of Artificial Neural Networks (ANNs) as a tool to support the tasks of cost prediction, mapping costs to engineering decisions, and risk management during the early stages of a design's life-cycle. ANNs are a modeling tool based on the computational paradigm of the human brain and have proved to be a robust and reliable method for prediction, ranking, classification, and interpretation or processing of data. / Kristopher David Netemeyer. / S.M.in Engineering and Management / Nav.E.

Thesis (Nav. E.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering; and, (S.M. in Engineering and Management)--Massachusetts Institute of Technology, Engineering Systems Division, System Design and Management Program, 2010. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 71-72). / Early stage ship design decisions continue to be a challenge for naval architects and engineers. The complex interactions between the different elements of the ship and the broad spectrum of disciplines required in ship design make it difficult to fully realize the effects and limitations early decisions place on design flexibility. Naval ship design has primarily focused on using point based design methods that do not necessarily produce the most cost effective, innovative, and high quality designs. Recognizing these shortcomings, U.S Navy design is exploring the use of Set Based Design (SBD) principles and methodology in designing the fleet for the 21st century. Existing research has shown the merits of SBD in other industries; however, research on the use of SBD in naval design does not exist. The thesis explores how to execute SBD in light of the recent restructuring of the U.S. Navy acquisition process calling for the use of SBD in pre-preliminary design. This is undertaken using the knowledge gained from exploration of the Ship-to-Shore Connector (SSC) program, the first use of SBD in a new start acquisition program. The thesis concludes by applying the derived information to an early stage submarine concept design. This effort focused on how to develop submarine design parameters and exploration of how to create and reduce integrated concepts. / Matthew C. Frye. / S.M.in Engineering and Management / Nav.E.

Thesis: S.M., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 2014. / Thesis: S.M. in Technology and Policy, Massachusetts Institute of Technology, Engineering Systems Division, 2014. / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 209-218). / This thesis is concerned with the design of complex artificial systems. For such systems, there is a growing need to deliver value to stakeholders beyond the initial functional requirements and to cope with rapidly changing outer environments. This thesis presents a conceptual framework and a structured approach for thinking about and designing systems that can exhibit the emergence of desirable lifecycle properties (i.e., ilities). To set the ground for the research contributions, a literature overview on (1) complex sociotechnical systems, (2) uncertainty in such systems, and (3) ways to cope with such uncertainty is given. Furthermore, the larger research effort concerning a method for architecting Systems of Systems with ilities is discussed to frame the remainder of the thesis. The dynamic system perspective for design is discussed, as well as a formal way of modeling the space of possibilities for designers of complex systems (i.e., what the system can be, as well as what its outer environment and expectations can be). In this perspective, uncertainty is modeled as perturbations, which are operators on these spaces of possibilities. Similarly, ility-driving elements (IDEs) are introduced and modeled as operators on such spaces as well. Two main types of ility-driving elements are discussed and formally defined: change options and resistance properties. The former, akin to real options in business, enable the system to change over time so as to cope with perturbations and sustain (or enhance) value delivery. The latter, on the other hand, impede undesired changes in system value delivery. Lastly, IDE Analysis - a structured approach for generating, evaluating and selecting ility-driving elements - is introduced, and demonstrated on a running case application to a Maritime Security System of Systems. This approach requires an initial baseline design concept, and considers a set of relevant perturbations as a starting point. The thesis ends with general discussions around applicability of research and possible areas for future research, as well as conclusions regarding key contributions. / by Nicola Ricci. / S.M. / S.M. in Technology and Policy

Thesis (Nav. E.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering; and, (S.M. in Engineering and Management)--Massachusetts Institute of Technology, Engineering Systems Division, 2010. / Page 166 blank. Cataloged from PDF version of thesis. / Includes bibliographical references (p. 77-80). / The U.S. Navy designs and operates the most technologically advanced ships in the world. These ships incorporate the latest in weapons technology, phased array antennas, composite structures, signature reduction, survivability, modularity, power systems, computing systems, and automation. The modem day warship is an exceptionally complex system and the design process is long and intricate, spanning several years from feasibility studies to detailed design. The plethora of new technologies being introduced in any single ship design increases the complexity of the ship design process making it ever more challenging to meet the needs of the stakeholder in terms of capability, cost, and risk. Systems architecture provides a way to understand, design, and manage this complexity by representing the system as an abstraction of elements and the relationships between those elements. Model-Based Systems Engineering (MBSE) has been a recent initiative in the systems engineering community to enhance the systems engineering process by streamlining requirements traceability and improving communication amongst the various stakeholders. MBSE methods have been used in industry to develop systems architecture in a robust and comprehensive manner. In the ship design process, there is a significant need to ensure that the architecture is not only well-defined, but also addresses the needs of the stakeholders. This thesis explores the use of MBSE to develop systems architecture with application to Navy ship design and acquisition. / by Nadia A. Tepper. / S.M.in Engineering and Management / Nav.E.

Thesis (Nav. E.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering; and, (S.M. in Engineering and Management)--Massachusetts Institute of Technology, Engineering Systems Division, 2010. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 63-64). / Could transparency between current disparate methods improve efficiency in early stage submarine design? Does the lack of transparency between current design methods hinder the effectiveness of early stage submarine design? This thesis proposes that coordinating data and design methods from current disparate sources would improve the initial early stage submarine design process. Improvements achieved through knowledge capture include: " the making available of options in determining key naval architecture values, " the ability to compare and contrast said options, both by results and underlying principles/assumptions, " and an overall process for developing key naval architecture values, to be used in later stages of design, that is easily expandable to incorporate further unleveraged design processes or newly developed data. The designer is encouraged through this approach to critically evaluate the data, customer requirements, and design philosophy they are bringing to the design. Capturing the knowledge of multiple design traditions means the decisions and calculations made while stepping through a design are no longer locked into a single frame of reference. The appropriateness of each decision is better understood within the context of the greater knowledge of submarine design. This flexibility in approach allows decision making such that the assumptions made during design best reflect the design scenario. Use of an open architecture to map how key naval architecture values are handled in different current methods may also provide the designer with insights which would otherwise remain hidden. / Eli A. Sewell. / S.M.in Engineering and Management / Nav.E.

Thesis: Nav. E., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2015. / Thesis: S.M. in Engineering and Management, Massachusetts Institute of Technology, Engineering Systems Division, 2015. / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 85-86). / Hydrodynamic analysis of two models of the Offshore Floating Nuclear Plant [91 was conducted. The OFNP-300 and the OFNP-1100 were both exposed to computer simulated sea states in the computer program OrcaFlex: first to sets of monochromatic waves, each consisting of a single frequency and waveheight, and then to Bretschneider and JONSWAP spectra simulating 100-year storms in, respectively, the Gulf of Mexico and the North Sea. Hydrodynamic coefficients for these simulations were obtained using a separate computer program, WAMIT. Both models exhibited satisfactory performance in both heave and pitch. An alternative design of the OFNP-300 was developed and similarly analyzed in attempt to further improve hydrodynamic performance. A catenary mooring system was designed and analyzed for both plant models. The number of chains and the length of each were selected to ensure the mooring systems would withstand, with sufficient margins of safety, the maximum tension produced in a 100-year storm. This analysis was conducted both with all the designed mooring lines intact, and with the worst-case line broken. A lifecycle cost analysis of various mooring systems was conducted in order to minimize the cost of the mooring system while maintaining adequate performance. / by Matthew Brian Strother. / Nav. E. / S.M. in Engineering and Management

Thesis (S.M. in Naval Architecture and Marine Engineering)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering; and, (S.M.)--Massachusetts Institute of Technology, Engineering Systems Division, 2013. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 82-83). / The design of ship structures was normally optimized to reduce construction material and maintain adequate strength while adhering to a given classification society's rules. In the case of Polar Class vessels, where weight minimization was important, higher fabrication labor costs occurred due to the closely spaced frames and thicker material needed. There was a cost trade-off between minimizing material under the traditional design method and designing a ship that was easier to construct at the shipyard, i.e. designing for downstream processes. Using the newly defined Unified Requirements for Polar Ships by the International Association of Classification Societies Inc., a numerical tool was developed to minimize construction cost of the icebreaker's hull form. This tool allowed the user to tailor the labor and material metrics to represent a specific shipyard. The tool then specified an optimum structural solution in terms of minimum weight and production cost. / by Stephen S. Normore. / S.M. / S.M.in Naval Architecture and Marine Engineering

Thesis (Nav. E.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering; and, (S.M. in Engineering and Management)--Massachusetts Institute of Technology, Engineering Systems Division, 2010. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 91-92). / A hardware model of a shipboard electrical distribution system based on aspects of the DDG 51 Flight IIA, Arleigh Burke class, 60Hz Alternating Current (AC) and the future direct current (DC), zonal electrical distribution system (ZEDS). These distribution boards were designed and built for the purpose of testing electrical system components at the Massachusetts Institute of Technology's Laboratory for Electromagnetic and Electronic Systems (LEES). The combination of existing electrical generators and the newly created electrical distribution boards will provide a hereto unattained level of access for testing and evaluating a number of research topics currently being worked on at LEES. The level of reality inherent in this system will enable the user to refine experimental hardware and software in a safe and controlled environment. The user will benefit from a quicker product development process. Additionally, the ability to easily produce verifiable records to demonstrate the effectiveness/applicability of their individual experiments will help to progress research at LEES along the product development path. Two 5 kW generators serve as electrical generation for the ZEDS benchtop emulator boards. The hardware models support experimentation with AC and DC ZEDS power loading and protection. The hardware models reflect the AC ZEDS architecture employed on the DDG-51 class destroyers. The emulator is a three phase electrical system with both port and starboard buses, a computer interface to control the generators and contactors or solid state relays through a graphic user interface (GUI). The system is capable of being configured and operated in a split plant, parallel or single generator plant configuration. / by Chad N. Tidd. / S.M.in Engineering and Management / Nav.E.

Thesis (Nav. E.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering; and, (S.M.)--Massachusetts Institute of Technology, Engineering Systems Division, 2005. / Includes bibliographical references (p. 85-88). / Concept studies for warship designs typically focus on ship performance characteristics by setting design goals for such things as speed, range, and cost. However, warships generally operate as part of a larger battle or strike group. Therefore, the designs should be evaluated as part of a system of multiple ship systems since designing each ship individually may result in underutilized and excess equipment and capability; in other words an inefficient design of the system of systems. This thesis examines the simultaneous design of several ships using the sea base concept as an example application of a network of ships working together. The number and characteristics of these ships determine the mission performance of the sea base. To properly design any of the sea base ships, the interrelationships must be included. A mission simulation is used to combine the performance characteristics of different ship designs into a single performance objective: the time to deliver a brigade size combat force to its assigned objectives. / (cont.) To enable the design of multiple ships, collaborative optimization, a multilevel optimization approach, was used to decompose the problem into individual ship design optimizations with system level interfaces controlled by a system of systems optimization algorithm. This allowed each ship to use techniques and algorithms best suited to reach an optimal design without impacting the design approaches used by the other ships. The classical collaborative optimization approach was relaxed to include multiple objectives such as performance and cost, thus developing a range of solutions which represent the tradeoff between these objectives. / by Robert A. Wolf. / S.M. / Nav.E.