Experimental Measurement of the Interaction of an Oscillating Wing with a Vertical Gust

Recent computational studies have shown that the effects of a large vertical gust might be mitigated by oscillating wing motions. An experiment was developed to validate and further investigate the effectiveness of oscillating wings as a gust mitigation technique. A full span NACA 0012 wing model was pitched about 1/4 chord at a reduced frequency of k = 0.5. Oscillation amplitude was held fixed at α = +/- 4°.  The wing model interacted with the Actuated Recirculating Gust Generator for sUAS Studies (ARGGUS) developed at the Army Research Lab, which produced a gust with Gust Ratio (GR) of 0.3 at a Reynolds number of Re = 12,000. The experiments were designed to investigate three separate cases: the interaction of an oscillating wing with a gust, a pitch down response maneuver while oscillating to evaluate whether quasi-attached flow could be maintained through the gust interaction, and a test of gust approximation via superposition. The gust approximation case mimicked the effective angle of attack generated by the gust and superimposed that on the oscillating motion profile. Particle Image Velocimetry was used to capture the flow field and the underlying physics of the problem will be discussed.