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April 2011 www.sname.org/sname/mt demonstration of four 22 megawatt full-scale prototype waterjets on a U.S. Navy LCS. The LCS acquisition pro- gram oce and ONR have executed a technology transition agreement to formally transition the demonstrated technology to this very important navy program. rough careful design and optimization, Rolls-Royces Axial Mk1 design will deliver high propulsive eciency and signicantly increased cavitation margins, while reducing the footprint on the vessel from the exist- ing propulsion solutions. ONR is also exploring other potential applications for the compact high-power waterjet design in the navys combatant craft community. In these small patrol and riverine boats, reduced size and increased cavitation margins can pro- vide signicant benet. e issue of high power density will continue to be important for many water- jet applications, from small high-speed combatants to commercial applications. As hydrodynamic designs continue to improve from research and devel- opment, greater power density from improved ow and reduced cavitation will be possible. Additionally, the chang- ing spectrum of materials available for waterjet manufacture will permit dif- ferent structural design congurations. Taken together, these advances will no doubt free up more of the available design space, enabling the possibility of yet higher-density waterjet propulsion in the not-so-distant future. MTFrank Lanni is chief engineer, naval waterjets U.S. for Rolls-Royce Naval Marine Inc., and is principal investigator for ONRs Compact High Power Den- sity Waterjet FNC program. FURTHER READING To learn more about waterjet propulsion, check out the following materials. The Future Naval Capabilities (FNC) program, overseen by the Oce of Naval Research, provides technology solutions to operational navy requirements. Learn more at www.onr.navy.mil/en/Science-Technology/Directorates/Transition/ Future-Naval-Capabilities-FNC.aspx John Allison presented a paper entitled Marine Waterjet Propulsion? at the 1993 Annual Meeting of the Society of Naval Architects and Marine Engineers. The paper can be purchased by SNAME members for $20 at www.sname.org. Under the Publications tab, select Technical Papers, then search by authors last name. Hydrodynamic and cavitation performance testing of a model scale impeller at Rolls-Royce Hydrodynamic Research Center. Fundamental hydrodynamic theory suggests that the highest pump eciencies can be obtained with the inclusion of some growth in the mean meridional ow path.