Very Low Noise, High Efficiency Propeller Designs for Small UAVs

"The objectives of this Phase I SBIR are to design, fabricate, test, and evaluate low noise, highly efficient propellers at two different airspeeds over a range of propeller rpm. The noise and performance results will be compared with the best (chosen apriori) commercially available two-bladed propeller. The quiet, highly efficient propeller will be designed to maintain optimum propulsive efficiency while still meeting the low noise objectives. This Phase I program uses a combinedtheoretical-experimental approach with an emphasis on producing propeller designs that meet noise and performance goals with less emphasis on mass production design and manufacturing. Design variables such as propeller diameter, blade number, blade shape,etc., will be systematically analyzed to achieve program objectives. A novel hub/blade design will facilitate parametric testing so that theory can be validated early and often. Manufacturing techniques are developed to produce five propellers of thesame design for testing by the Navy at the end of Phase I. In the later stages of the program (Phases II and III), new designs will be proposed that further reduce noise levels while maintaining good performance. Mass production methods will be employedto produce propellers that are durable and consistently perform as designed. The realization of a very quiet, highly efficient, safe, cost-effective propeller for small UAVs will be welcomed by DoD, other go