Hybrid Propulsion Systems for Undersea Weapons

This STTR focuses on design of a hybrid propulsion system for a heavyweight torpedo. The hybrid torpedo propulsion system is designed to allow effective operation over a large turndown ratio, improving the weapon’s suitability for a broad range of missions including littoral water duty. The improved flexibility of hybrid torpedoes should improve the Pk and Pck (probability of kill, probability of counter-kill) metrics and may offer savings in Total Ownership Cost (TOC) over conventional torpedo propulsion systems. Two parallel Phase I STTRs were completed on hybrid concepts. Barber-Nichols analyzed a chemical oxygen generation system and FuelCell Energy analyzed a solid oxide fuel cell (SOFC) system which would form the low power subsystem. Both Phase I studies completed trade studies on the performance attributes of various resultant propulsion systems. The conclusion was that both the chemical oxygen generator and the SOFC were significant enabling technologies. This Phase II effort combines these two efforts into a coordinated technology advancement program. The program advances the key technologies through Option 1 then offers alternative Option 2s, one providing integration of key subsystems plus a total system design, the other providing less subsystem integration but offering a limited propulsion system breadboard demonstration.