Very Low Noise, High Efficiency Propeller Designs for Small UAVs

"This topic addresses the design and development of novel propeller shapes, configurations and construction that significantly reduce the radiated noise of small propellers while simultaneously maintaining relatively high propulsive efficiency. Propellersare fast becoming the dominant noise source in small UAVs, as muffler designs improve. The conflicting goals of low noise, high efficiency and low cost are complicated by structural and aerodynamic interaction with the single cylinder diesel engine andairframe. In this project we draw from international expertise to analytically and experimentally pursue optimized quiet, efficient and inexpensive designs. Besides the obvious military application, this technology will benefit model airplane hobbyists andresidents of nearby flying fields as open space becomes increasingly scarce."