In response to the Fiscal Year 2006 National Defense Authorization Act, the US Navy conducted an evaluation of alternative propulsion methods for surface combatants and amphibious warfare ships. The study looked at current and future propulsion technology and propulsion alternatives for these three sizes of warships. In their analysis they developed 23 ship concepts, only 7 of which were variants of medium size surface combatants (MSC,21,000-26,000 MT). The report to Congress was based on a cost analysis and operational effectiveness analysis of these variants. The conclusions drawn were only based on the ship variants they developed and not on a representative sample of the feasible, non-dominated designs in the design space. This thesis revisits the Alternative Propulsion Study results for a MSC, which were constrained by the inability of the Navy's design tools to adequately search the full design space. This thesis will also assess automated methods to improve the APS approach, and examine a range of power generation alternatives using realistic operational profiles and requirements to develop a notional medium surface combatant (CGXBMD). It is essential to base conclusions on the non-dominated design space, and this new approach will use a multi-objective optimization to find non-dominated designs in the specified design space and use new visualization tools to assess the characteristics of these designs. This automated approach and new tools are evaluated in the context of the revisited study. / Master of Science

This thesis describes the design optimization of two different types of vessels. They are LHA(R), a replacement for the US Navy amphibious assault ship and DDG51, a destroyer class vessel. The overall measure of effectiveness (OMOE) and the lead ship acquisition cost (LCA) are considered to be the objective functions. The evaluation of feasibility of the designs and various ship parameter calculations are performed using the US Navy ship design evaluation software ASSET. ASSET is integrated with the design optimization software DARWIN to obtain results representing the best designs over a range of LCA. Model Center software is used to integrate the processes ASSET and Darwin. The results generated will provide the owner with the best designs possible (designs with high OMOE) over a range of LCA. This thesis is mainly of academic interest. The results generated could help the owners to look at various design options available for the amount of money they are willing to spend. / Master of Science