Aerodynamic and Aeroacoustic Performance of Airfoils Fitted with Morphed trailing edges

Experimental and numerical studies of a simple NACA 0012 airfoil fitted with two different flap profiles were successfully carried out to characterize their aerodynamic and aeroacoustic performance. The airfoil was tested with two flap configurations with different flap camber and a flap deflection angle of = 10. The aerodynamic lift and drag measurements show improved lift-to-drag performance for the morphed flap airfoil. Surface flow visualization has shown delayed separation for the morphed flap airfoil. Flow measurements showed that the downstream wake development can be significantly influenced by the flap profile. Particle Image Velocimetry was used to study the flow over the flap and airfoil wake. The tests were carried out for a flow velocity of U1 = 20 m/s, corresponding to a chord-based Rec = 2:6 105. The mean velocity contours at the wake showed increased wake deficit and turbulent kinetic energy for the morphed flap airfoil compared to the hinged flap airfoil. The turbulent kinetic energy results displayed a characteristic double peak behavior which was also the dominant content of the streamwise normal Reynolds shear stress component. Large eddy simulations were carried out for the two airfoils and the results were validated with the experimental measurements. The boundary layer profile from the computations showed delayed separation. The wall pressure spectra close to the trailing edge showed increased energy for the morphed flap airfoil relative to the hinged flap airfoil. The Curle’s acoustic analogy was used to calculate the far-field noise measurements and morphed flap airfoil showed increased noised compared to the hinged flap airfoil.