Large Hydrofoil Transmission System Study.

摘要

This report presents the results of a study to determine the performance and physical characteristics of an ac electrical system intended for use as the propulsion system of large hydrofoils. Section I provides a technical description of the system in terms of performance, weight and component characteristics. Section II describes anticipated problems associated with development of the system and its components, and includes activities through design and fabrication, and qualification of an integrated system. Two system configurations are considereed in this study. Configuration I which is the preferred one, consists of two direct-turbine-driven ac generators supplying electrical power to either foilborne or hullborne propeller induction drive motors. Conventional switchgear is used for connecting the generator to either the foil or hull drive motors. Each induction motor supplies power to a fixed pitch propeller via a planetary type gearbox. Speed and power output of each induction motor is controlled by fuel to the turbine. Configuration II consists of independent foilborne and hullborne propulsion systems. For takeoff and foilborne operation, two direct LM2500 turbine-drive ac generators supply electrical power to the foil propeller induction motors. Operation in this mode is identical to Configuration I. Configuration II provides a trade off between greater system weight, against a lower hullborne fuel consumption rate obtained by operating smaller turbines in hullborne mode. This provides, potentially, a greater hullborne range.