Gust mitigation using morphing wings at low Reynolds number

The interaction of wings with vertical gusts is still not well understood, especially at the lower Reynolds numbers relevant to small Uncrewed Aerial Systems. Studies at higher Reynolds numbers with relatively slowly developing gusts have shown that morphing wing camber is effective at mitigating gusts, while at low Reynolds number, gusts are understood to be a leading edge phenomena relatively unaffected by the trailing edge. This study evaluates one-way trailing edge morphing and oscillating trailing edge motions with respect to the ability to mitigate vertical gust impacts. The results show that, for the gust condition tested, one-way trailing edge morphing at low Reynolds number acts similarly to higher Reynolds number studies. However, the long duration of the gust tested showed that one-way trailing edge morphing can only mitigate gusts for a certain length of time, after which stall occurs. Oscillating the trailing edge is shown to mitigate gusts in a similar fashion to prior studies on oscillating wings, where predictable oscillatory lift is possible. However, oscillating the trailing edge is only able to generate a predictable lift behavior for a certain length of time, after which the leading edge effects of the gust dominate over trailing edge motion. Higher oscillation frequency and Strouhal number are shown to have a detrimental effect on the predictability of lift during gust interactions, but have no effect altering the time at which highly unsteady stall dynamics occur.