Morphing thickness in airfoils using pneumatic flexible tubes and Kirigami honeycomb

Abstract

The work describes a concept to morph the thickness of airfoils using a combination of pneumatic flexible tubes within a Kirigami honeycomb configuration that represents the wingbox structure. The configuration of the honeycomb/inflatable tube structure is composed by a pair of flexible tubes sandwiched between two custom honeycomb layouts. At zero input pressure, the tube assumes a sinusoidal shape, which is reduced to a straight configuration and increase of the airfoil thickness when pressure is applied. An analytical model is developed for design purposes to consider the actuation authority and thickness change provided by the system proposed. The results are benchmarked against experimental tests carried out on a reduced-scale demonstrator.