Naval Engineers Journal 

Abstract: Viscous drag reduction of a fully-submerged body of revolution is obtained by creating hydrogen gas on the hull by electrolysis. The bubbles alter both the laminar and turbulent boundary-layer characteristics resulting in a significant reduction in the viscous drag on the 3-foot model up to a speed of 8.5 feet per second, the maximum test velocity. Results show that the amount of drag reduction depends on the ratio of the mass flow of water in the wake to the time-rate of hydrogen mass produced beneath the boundary-layer. The results presented herein are model results and should NOT be considered directly applicable to any existing prototype.

Abstract: On February 4, 2008, Admiral Paul Sullivan, Commander of the Naval Sea Systems Command, sent out a letter entitled: Ship Design and Analysis Tool Goals. The purpose of the widely distributed memorandum was to state the requirements and high-level capability goals for NAVSEA design synthesis and analysis tools. In this memo, Admiral Sullivan expressed the need for evolving models and analysis tools to be compatible with, among other things, set-based design (SBD). Admiral Sullivan's memo was a major step toward improving ship design programs with new, more powerful analytical support tools but many have asked, “What is Set-Based Design and how does it relate to Naval Ship Design?” SBD is a complex design method that requires a shift in how one thinks about and manages design. The SBD paradigm can replace point-based design construction with design discovery; it allows more of the design effort to proceed concurrently and defers detailed specifications until trade-offs are more fully understood. This paper describes the principles of SBD citing improvements SBD in design practice that have set the stage for SBD, and relating these principles to current Navy ship design issues.