Wake vortex control using static segmented Gurney flaps

A study to assess the potential for using static segmented Gurney flaps, also known as miniature trailing edge effectors, for active wake vortex alleviation is conducted using a half-span model wing with NACA 0012 shape and an aspect ratio of 4.1. All tests are performed with the wing at an 8.9 deg angle of attack and chord-based Reynolds number around 350,000. The wing is equipped with an array of 13 miniature trailing edge effector pairs. Each miniature trailing edge effector has a flap that in the neutral position rests behind the blunt trailing edge of the wing, and in the down position extends 0.015 chord lengths perpendicular to the freestream on the pressure side of the wing. Measurements of section lift coefficient are made using pressure taps to assess the effect of various miniature trailing edge effector configurations on the spanwise lift distribution. Particle image velocimetry and five-hole probe measurements are made on the trailing vortex to assess the steady-state effects of different flap configurations. It is found that the miniature trailing edge effector configurations with a large fraction of the span actuated down are able to deflect the vortex predominantly in the lift direction, whereas miniature trailing edge effector configurations with a small fraction of the span actuated down are able to deflect the vortex in both the spanwise and lift direction. A maximum spanwise deflection of 0.041 chord lengths is possible while nearly conserving total lift. These results suggest that certain miniature trailing edge effector configurations, if varied in time, may be useful for wake alleviation.