Aerodynamic Performance and Wake Development of Airfoils with Serrated Trailing-Edges

A comprehensive experimental study has been performed for symmetric NACA 0012 and cambered NACA 65(12)-10 airfoils with a variety of trailing-edge serrations over a wide range of angles of attack. Results are presented for the aerodynamic force measurements, wake development, and energy content of the wake turbulent structure at moderate chord-based Reynolds numbers (Re-c =2x10(5)-6x10(5)). The aerodynamic force measurements have shown that the use of trailing-edge serrations for cambered airfoils can lead to significant reductions in the lift coefficient at low angles of attack but does not particularly change the stall characteristics of the airfoils. The wake flow results have shown that the use of serrations can lead to considerable reduction of the wake turbulence intensity, which is shown to be due to a complex interaction between the flowfield over the tip and root planes of the serration in the near wake. Furthermore, power spectral density results pertaining to wake turbulence indicate that the implementation of serrations deenergizes the wake flow over a wide range of frequencies.