Abstract
A bioinspired mechanism is proposed for flow control and separation delay in morphing wing aircraft. The device uses bending actuators that are directly bonded to a flexible skin on the top surface of the wing. The bending actuators are oscillated such that a traveling wave pattern propagates from the leading edge towards the trailing edge — a type of motion that is known to be used by eels and other aquatic creatures for propulsion. This experimental study examines the properties of an actualized mechanism for generating traveling bending waves through a viscoelastic morphing skin made of spring steel strips layered with a plastic sheet. Previous experiments were of elastic structures having purposefully minimal damping, consisting of spring steel sheets without any plastic layer. Elastic properties dominated and waves were actuated using a method that required at least two sets of actuators in order to produce traveling waves — one leading edge, and one trailing edge. However, we have found that in a viscoelastic morphing skin, only one actuator set is required to generate traveling waves. Experimental results are presented and a 1-D transfer matrix model is developed for a viscoelastic Euler-Bernoulli beam in vibration.
