The Application of Curved Fluidic Oscillators for Leading Edge Flow Control

Abstract

A new design of fluidic oscillator, in which the oscillator is curved along its primary flow direction, allows for a sweeping jet to be placed near the leading edge of a wing as an active flow control device. Previous studies of fluidic oscillator applications have shown their promise as an active flow control device by increasing the lift over a wing and the effectiveness of aircraft control surfaces. However, the planar extent of the flat fluidic oscillators creates challenges when trying to implement them optimally in a confined geometry. The application of these new curved oscillators is experimentally investigated on the leading edge of an upswept NACA 0018 airfoil full span wing. Global load cell measurements of lift and drag, suction surface static pressure taps, and particle image velocimetry data are presented. The effect on lift, drag, and stall location at a Reynolds number of 100,000 is documented for a variety of oscillator chordwise locations near the leading edge. While further aft positioned oscillators produced a larger increase in maximum lift, more forward locations resulted in better post-stall performance and delayed flow separation over the wing.