From Aeroacoustics Basic Research to a Modern Low-Noise Rotor Blade

Abstract

In 2015, Airbus Helicopters unveiled the secrecy around its Dauphin successor and presented the all new H160 helicopter. A special feature that immediately attracted attention was its unusual and revolutionary fore-aft swept main rotor blade. This design, which aims to significantly reduce the blade-vortex interaction noise signature and reduce high-speed forward flight power requirements, was first investigated in the 1990s. At this time, DLR and ONERA formed a joint team to acoustically optimize a rectangular reference rotor blade. Based on state-of-the-art comprehensive rotor codes and a 50/50 work share, the ERATO rotor blade design was developed, patented worldwide and tested on both a rotor test rig and in the wind tunnel. Airbus Helicopters (then: Eurocopter) adopted the design, optimized hover and forward flight high lift performance and prepared it for serial production, as the Blue EdgeTM rotor blade on the Airbus Helicopters H160 helicopter.