High-Efficiency Propulsion for EMATT Sprint Speed Capability
Navy SBIR FY2013.1

Sol No.: Navy SBIR FY2013.1
Topic No.: N131-053
Topic Title: High-Efficiency Propulsion for EMATT Sprint Speed Capability
Proposal No.: N131-053-0304
Firm: Aurora Flight Sciences Corporation
9950 Wakeman Drive
Manassas, Virginia 20110
Contact: Benjamin Smith
Phone: (617) 229-6781
Web Site: www.aurora.aero
Abstract: Aurora Flight Sciences and the Lockheed Martin Sippican propose to develop a new propulsion system to increase the top speed of an EMATT (Expendable Mobile ASW Training Target) vehicle to 14 knots. Aurora will perform systems-level analysis to determine propulsion system requirements and component-level specifications. Aurora and Lockheed will work with top battery manufacturers to develop a safe, high energy-density battery that provides sufficient power and capacity to meet the sprint speed performance requirements. Aurora will size a high-efficiency motor matched to a novel propeller design which will ensure efficient operation across the range of EMATT operating speeds. Efficiency gains will be realized through the design and optimization of a new fixed-pitch propeller which matches the propeller load to the most economical motor operating conditions. Component-level and total-vehicle performance will be estimated analytically to assess performance and stability. Vehicle safety will be assessed, risk reduction activities and opportunities to improve vehicle performance will be identified, and a Phase II development plan will be identified. In the Phase I Option, Aurora will investigate a hydroelastically tailored propeller to further improve propeller and motor efficiencies across all operating speeds.
Benefits: The benefit of developing a high-efficiency propulsion system (safe, high-energy density batteries, high-efficiency motor carefully matched to an optimized fixed-pitch propeller) is that the operating speed and/or endurance of an underwater vehicle can be increased while limiting growth of vehicle size. Hydroelastically tailored propellers have the additional benefit of being optimized and multiple operating speeds to provide high-efficiency operation across the range of operating speeds. Furthermore, hydroelastically tailored propellers provide additional stability against hydroelastic instabilities, which may result in higher propeller reliability and lower weight. Because the technology is applicable to a wide range of underwater vehicles, such as torpedoes, oil and gas ROVs, and even small boats, Aurora will explore multiple commercialization opportunities to adapt the technology to various platforms that would benefit from higher efficiency. The immediate commercialization opportunity is to integrate the propulsion system into an EMATT vehicle to demonstrate sprint speed capability and subsequently license the propulsion technology to the manufacturer of the next generation EMATT.