Efficient and Quiet Propeller Design for Small Unmanned Aerial Systems (SUAS)

Propellers have received little R&D emphasis over the past 50 years especially for small propellers. There has been a rapid increase in the use of small unmanned aircraft systems (SUAS) for military and commercial uses. This sudden demand has created a technology gap for small propellers. Radio-controlled (RC) propellers with basic airfoil sections and design practices are not optimized for the flight regime and mission of SUAS. These offer mediocre performance and high acoustic signatures due to the higher revolutions per minute (RPM) levels associated with internal combustion engines (ICE) thus allowing enemy forces to easily detect the presence of SUASs. With the recent push towards electric motors and quieter ICE technologies, there is a need for quieter propeller designs for military and commercial operations. This proposal aims to facilitate the development of innovative propeller designs for SUAS with less than 50 hp. The proposed solution will exploit the use of advanced parametric modeling, noise prediction algorithms and evolutionary airfoil sections to yield quieter propeller designs. This methodical approach combined with real experience designing and testing propellers and SUAS flight vehicles will result in achievement of the program’s acoustic and performance goals and thus improved SUAS mission endurance and survivability. BENEFIT: Commercialization of efficient and quiet propeller design technologies include licensing to numerous existing and future SUAS contractors. There are a number of contractors developing high endurance, ISR-focused SUASs for AFSOC, USSOCOM, and the AFRL’s Tube-Launched Expendable UAS (TLEU) program that require stealthy operation and need quiet propellers. Also the Navy’s Small Tier II UAS and the Army’s next version of Shadow (RQ-7C) will benefit from efficient and quiet propeller technologies. Commercial organizations need quieter propeller technology to operate in National Airspace for law enforcement, Homeland Security, emergency services, search and rescue, and disaster relief missions.