Innovative Engines for Small Unmanned Aerial Systems (SUAS)

TECH FOCUS AREAS: Autonomy TECHNOLOGY AREAS: Air Platform OBJECTIVE: This topic is for innovative propulsion for SUAS (Group 2 thru small Group 4 UAS) that supports Global ISR missions such as: long range persistent ISR, air launch extended reach ISR, and time critical responsive ISR. The topic shall address how innovative propulsion will allow for improved UAS capabilities, the use of UAS in mass, and consider air launch and performance at altitude (25,000 ft AGL). Objective: A concept design for innovative propulsion of GR2 (2 to 7 hp), GR 3 UAS (10 to 100 hp), and small GR 4 UAS (500 to 700hp). Small engines are defined as less than 1000 lbs thrust and under 1000 HP. DESCRIPTION: To keep ahead of the changing global environment, improved capabilities for UAS systems for Global ISR are needed. The USAF 2030 Science and Technology Strategy seeks to: Develop and Deliver Transformational Strategic Capabilities: thru Global Persistent Awareness and Complexity, Unpredictability, and Mass. This objective can be achieved thru increased capabilities from SUAS with improved propulsion. Present day GR2 thru GR4 propulsion systems are slow, noisy, inefficient, and lose performance at altitude. These SUAS use piston and rotary engines which are gasoline operated and have limited life of approximately 200 hours and fly at 100 knots or less. Piston engines in this class have low thermal efficiencies, less than 20% and low specific power of approximately 0.5 hp/lb. What is needed is innovation in the UAS propulsion for quiet operation, performance at altitude, light weight, improved efficiency, and high power to weight. PHASE I: The proposals should expand the technical enterprise upon teaming with non-traditional experts for propulsion innovations for GR 2 SUAS (less than 50 lbs GTOW), GR3 SUAS (less than 1350 lbs. GTOW), and GR4 UAS (less than 5000lbs). Non-traditional experts are those of authority/study that are outside of the UAS community/industry, but have novel concepts to meet the future S&T demands. Concepts in innovative propulsion are sought which include: internal combustion, detonation, and nuclear; which are more efficient, have higher specific power and more durable. The concept shall demonstrate the feasibility of the design, development and integration activities required for an operational SUAS. Small Propulsion are engines less than 1000 HP/1000 lbs thrust. Key design attributes are; Specific Power > 1.0 HP/lb; SFC < 0.5 lbs/hp-hr; and +500 hr life. PHASE II: Builds off of the PH I effort and consists of the development of a prototype and takes the prototype to a ground test to demonstrate its power, efficiency, acoustics and durability. This phase shall have a design review prior to fabrication and identify risks with risk reduction tests completed before the final engine demonstration. Further, teaming with operational users should be established to show how the new UAS capabilities will improve Global ISR thru improved SUAS propulsion. PHASE III DUAL USE APPLICATIONS: Integrate the innovative engine to a candidate UAS for flight testing. The innovative engine can be developed for commercial application for aviation, marine, and land-based power generation; hence being dual use in nature. REFERENCES: 1. Recent Innovations in Internal Combustion Engines by Nicole Moden; ISBN: 978-1632400017; M L Books International, 2015. 2. Internal Combustion Engines: Applied Thermosciences by Colin Ferguson and Allan Kirkpatrick; ISBN: 978-1118926529; Wiley 2015. 3. Small Internal Combustion Engine Testing for Hybrid Electric RPA by Isseyas Mengistu; ISBN 978-1249599838; BiolioScholar.