Application of Leading-Edge Tubercles to Enhance Propeller Performance

Aircraft propellers are known to experience flow separation at various flight conditions leading to efficiency variations from approximately 40-85%. By controlling flow separation, higher propeller efficiency and improved performance might be possible. In this paper a bioinspired passive flow control strategy that improves propeller performance is used by introducing protuberances, or tubercles, in the leading-edge region of a propeller blade. Experiments also revealed apparent improvements to propeller acoustic emissions. Propeller performance and noise signatures, evaluated against a reference propeller, are presented from experiments involving different propeller configurations modified with various combinations of tubercle geometry. Specific tubercle configurations exhibit improvements in efficiency up to 6% as well as redistributed directional and high-frequency broadband noise characteristics.