Morphing flap concept to reduce the flap side edge noise for aircraft wing slotted flaps

To reduce the aeroacoustic noise of wings with high lift devices, a morphing flap concept has been investigated, which has smoothly contoured flap connected smoothly to the outer main wing. Wind tunnel tests for NACA23012 half span wing model with flexible morphing slotted flap was conducted in Kyushu university 2m x 2m low-noise low-speed wind tunnel, at the condition of up to U= 40m/s, Re=1.3 x 10. Aeroacoustic noise measurement was carried out using phased array microphones and analyzed by the beamforming method. Three types of morphing flap configuration were compared with conventional single slotted flap. The wind tunnel test result showed that the morphing flap configuration suppress the flap side edge noise and lower overall sound pressure level with same level lift coefficient than conventional single slotted flap configurations.