Electro-aeromechanical modelling of actuated membrane wings

Abstract

a b s t r a c tThis paper presents a numerical investigation on the aeromechanical performance of dynamically actuated membrane wings made of dielectric elastomers. They combine the advantages of membrane shape adaptability, which produces increased lift and delayed stall, with the benefits of simple, lightweight but high-authority control mechanism offered by integral actuation. High-fidelity numerical models have been developed to predict their performance and include a fluid solver based on the direct numerical integration of the unsteady Navier-Stokes equations, an electromechanical constitutive material model and a non-linear membrane structural model. Numerical results show that harmonic actuation can either increase or reduce the overall aerodynamic efficiency of the wing, measured as the mean lift-to-drag ratio, depending on the ratio between the actuation frequency and the natural frequency of the membrane. In addition, the definition of a reduced-order model based on POD modes of the complete high-fidelity system provides an insight of the main characteristics of the dynamics of the coupled system.

Aeromechanics of membrane and rigid wings in and out of ground-effect at moderate Reynolds numbers

“…Proper-Orthogonal-Decomposition (POD) has previously successfully been applied to the flow field around membrane wings (Schmit et al, 2003;Lian et al, 2003) as well as membrane dynamics (Stanford et al, 2010;Buoso and Palacios, 2015;Shi et al, 2013). The complexity of membrane-vibrations requires a technique which is capable to identify and quantify twodimensional spatial structures in membrane-oscillations.…”

On-Demand Aerodynamics in Integrally Actuated Membranes with Feedback Control

“…The new variable is coupled with the displacement solution through the constitutive model [25]. Considering the thickness of the membrane allows the definition of the electrostatic Maxwell stress tensor in all threedirections, relaxing the incompressibility assumption that would be otherwise required [12].…”

“…Several coupled models for passive membrane wings have been proposed in the literature [9,10,11]. Buoso and Palacios [12] have extended them to a fully coupled electro-aeromechanical wing model and investigated the open-loop response of the actuated membrane. The actuation has shown to provide enough authority to drive the dynamic response of the system, with peaks of lift coefficient up to twice the reference, nonactuated one.…”

“…A previous work by the authors [12] has investigated the open-loop dynamics of actuated membrane wings in a low-Reynolds-number flow using a full-order coupled model. Further to those results, the same framework will be used in this paper to derive a suitable reduced-order model.…”

“…Section II summarizes the full-order coupled aero-electromechanical model of Ref. [12]. Section III introduces two low-order description for the actuated membrane wing.…”