Aerodynamic and aeroacoustic wind tunnel tests of a half wing model with a full-span droop-nose leading edge

A full-span droop-nose leading edge is proposed in the Clean Sky GRA project as a next-generation low-noise high-lift device. This device can prevent flow separation on the upper wing surface at large angles of attack and therefore provides high lift. The device is also considered to be promising for reducing noise because no gaps are found between the leading edge and the wing. These features have been admitted in CFD and CAA analyses. In this study, they were experimentally confirmed in wind tunnel tests using a 1:6-scaled half wing model. The model generally showed similar aerodynamic performance to that estimated in CFD analysis. An exception was that the droop-nose configuration provided very large lift and a large stall angle when no transition tripping devices were equipped. In an acoustic beamforming experiment, no extra noise sources were found at the droop nose leading edge. This device did not increase the noise level. By analyzing microphone signals in the far field, an indication of noise radiated from the wing model could be detected at higher frequencies, although entire noise spectra could not be determined because the microphone signals were largely contaminated by the noise from the wind tunnel itself.