Aerodynamic and Aeroacoustic Performance of Spanwise Morphed Airfoils

Experimental studies of a NACA 0012 airfoil fitted with six different spanwise morphed flap profiles were successfully carried out to characterize their aerodynamic and aeroacoustic performance. The airfoil was tested with six configurations with different spanwise flap camber with a maximum deflection angle of β = 10◦ on one side and a minimum deflection angle of β = 0 ◦ on the other side. The tests were carried out for a flow velocity of U∞ = 20 m/s, corresponding to a chord-based Rec = 2.6 × 105 . The aerodynamic lift and drag measurements showed that improved lift-to-drag performance is highly dependant on the spanwise flap camber. Flow measurements at the downstream wake locations were carried out using hot-wire anemometry. Flow measurements also showed that the downstream wake development could be significantly influenced by the spanwise flap profile. The turbulent kinetic energy results displayed a characteristic double peak behavior at some locations along the span of the airfoil flap. Some of the tested cases had larger regions of double peak behavior along the span compared to the others. Aeroacoustic measurements were carried out using a beamforming array placed at a distance of 1 m. The beamforming map showed that the noise levels along the span are highly dependant on the spanwise camber of the morphed trailing edge and they portray possible noise reduction at select frequencies.