Comparative study of effects of sweep and humps on high-speed propeller blades

Previous work on multidisciplinary optimization of high-speed propeller blades led to the emergence of humpy blades with or without sweep. The present paper is intended to deliver more insight into the potential benefits of such blades by means of a comparative study of four blade designs. These designs differ only in their respective chord distribution and tip sweep. Comparisons are given in terms of aerodynamic and aeroacoustic performance for the four designs operating either in identical flow conditions, hence different load, or in identical thrust conditions, hence slightly different flow conditions due to adaptation of the blade angle. The results highlight the potential of humpy designs to reduce noise in cruise conditions with a small loss of efficiency.