A Numerical Study on Smart Material Selection for Flapped and Twisted Morphing Wing Configurations

Abstract

The developments of innovative adaptive structures on Unmanned Aerial Vehicles (UAVs), such as morphing wings, can potentially reduce system complexities by eliminating control surfaces and their auxiliary equipment. This technology has the potential of allowing a UAV to adapt to different mission requirements or to execute a particular mission more effectively by maintaining an optimum airfoil section over a range of speeds for different segments of a mission profile. Studies on a number of smart materials candidates are currently available in the open literature to achieve wing morphing. The material selection depends on several factors including fast dynamic response, low weight, capability to operate over a wide range of flight conditions and low power consumption. This paper presents a review on smart materials technologies for UAV morphing wings. A numerical study in terms of power requirements is also presented for two morphing wing concepts: flapped and twisted wing planforms. The energy calculations for both morphing configurations were based on a two-step procedure. The first step consists of computing the aerodynamic energy using an in-house Vortex-Lattice (VL) based program. Subsequently the pressure field obtained from the first step is then mapped into a finite element mesh and the structural strain energy is calculated. The numerical results indicated that flapped morphing wings have a better aerodynamic performance when compared to twisted wings and different morphing levels can be achieved using lighter smart materials with lower specific energy for this configuration.

Construction of a Morphing Wing Rib Actuated by a NiTi Wire

“…Smart materials refer to a class of materials that are able to respond dynamically to selected external stimulus (Dasgupta 2013). The materials themselves are not "smart" in the sense that they passively react to an input rather than making decisions or adapting themselves to the environment (Donadon and Iannucci 2014). Some examples include piezoelectric materials, shape memory materials (alloys and polymers) and electroactive polymers.…”

Review of Wing-Morphing Technology

“…Perhaps the simplest one to notice is the lack of scalability. Most of the researches considered have been on the UAV scale and have used materials with questionable strength [28] on full-sized airplanes. This is because conventional materials cannot be used due to the aero-elastic requirements demanded by most morphing concepts.…”

Morphing aircraft based on smart materials and structures: A state-of-the-art review

“…To overcome the problems with traditional materials and structures, novel materials are required (Donadon and Iannucci, 2014; Lloyd, 2007). Smart materials and structures, which offer self-actuating, self-sensing, self-healing, self-assembly, and self-adaptive capabilities, have great potential for applications in morphing aircraft (Rodriguez, 2007; Simpson et al, 1998).…”