Unsteady aerodynamics of flexible wings in transverse gusts

Unsteady aerodynamics of two flexible cantilevered wings in transverse gusts has been studied by means force, velocity, and deformation measurements. The first bending frequencies the were range gust tested. measurements revealed that plunge angle due to deflections is generally small. However, it becomes large at resonant conditions significantly attenuates amplitude effective perceived wing, although unsteady lift difficult measure accurately for cases. As frequency increases, more wing experiences separated flow during cycle. Nevertheless, both wings, normalized smaller than those rigid with flows. When maximum attack a critical value, close theoretical predictions attached flows effect reduced In contrast, above value attack, can be amplified or attenuated, depending on frequency.