Fluid–structural dynamic characterization of an electroactive membrane wing

The interactions between low-Reynolds-number fluid flow and an electroactive membrane wing is characterized to illustrate changes in harmonic and transient behavior from electric field excitation of the membrane wing. The wing is constructed of a dielectric elastomer material that changes its tension as a function of the applied field. The field excitation leads to changes in the shape of the wing under aerodynamic loads and subsequently, increased lift and delay of stall. Prior work in time-averaged lift and drag characterization is extended to better understand dynamic characteristics. Benchtop membrane structural dynamics are compared with visual image correlation, hotwire measurements, and particle image velocimetry within a low-Reynolds-number wind tunnel. An applied electric field leads to a 13.7% reduction in structural resonance of the membrane under ambient conditions while wind tunnel measurements illustrate a 5.1% reduction in resonance under the same applied field. Despite these differences, the structural and fluid dynamic harmonics are closely correlated for low-Reynolds-number flow at 10 m/s.