The design of small propellers operating at low Reynolds numbers and associated experimental evaluation.

Small-scale Unmanned Aerial Systems (UASs) are becoming increasingly important in the field of intelligence, surveillance, and reconnaissance. As the desire for higher payloads and longer flight times increases, so does the need to optimize the performance of UAS components. It has been found that small UASs using propeller and electric motor combinations are susceptible to decreased efficiencies while operating in low Reynolds numbers conditions. This work details contributions made by Baylor University, in collaboration with the United States Air Force Academy, which include a custom propeller design, analysis, and solid-modeling code for experimental propeller models and a propeller test stand for use in the Baylor University subsonic wind tunnel with accompanying data acquisition code. As a result of the 46 custom propellers designed and tested, an efficiency increase of 7% and noise signature decrease of 12 dB has been achieved when compared to stock propellers on UASs of interest.