Robust fluid-structure interaction analysis of an adaptive airfoil using shape memory alloy actuators

Abstract

In the present paper, an aero-structure interaction model for the rapid simulation of morphing structures realized through shape memory alloy (SMA) actuators is presented. The aerodynamic simulation method implements a potential flow method strongly coupled with an integral boundary layer method in the context of a viscous-inviscid interaction approach, which includes a transition prediction model and a simplified shear stress-transport equation for the turbulence closure. The structural analysis model of the airfoil integrates a well-established SMA constitutive model for the prediction of the actuator behavior into finite element software. The two numerical models are loosely interconnected by exchanging geometrical and loading data at each iteration. An articulated 2-link adaptive mechanism for load alleviation purposes in horizontal axis wind turbine blades is investigated considering two different morphing scenarios: (1) operation of a single hinged flap; (2) combined movement of two sequential airfoil segments is attempted to achieve a smoother camber variation. The present fluid-structure interaction (FSI) model is employed with the aim to quantify its effect and benefits on the active shape control of the morphing airfoil, the actuator response, and the aerodynamic performance including lift and drag coefficients. The presented results demonstrate the robustness and numerical performance of the developed FSI method.

Shape control and design of aeronautical configurations using shape memory alloy actuators

“…Solo mou et al [12] developed a beam element that incorporates the thermo mechanical properties of SMA wire actuators. The study of [13] followed these developments, coupled the FE model with a lower fidelity fluid solver and performed a fluid structure inter action (FSI) study for a hinged flap configuration and a segmented airfoil, targeting wind turbine applications.…”

Fundamentals and working mechanisms of artificial muscles with textile application in the loop

“…NiTi and its shape memory properties were discovered by Buehler and coworkers in 1963 at the Naval Ordnance Laboratory (NOL), which in turn also coined the common product name 'NiTiNOL' [20]. SMA materials have been investigated thoroughly since then, and many applications have been developed, such as smart wings and flaps for aircrafts [52][53][54][55], deployable structures for aerospace application [56,57], fracture healing and structural damping in civil engineering [58], movable parts and mechanisms in automotives [59], actuators and grippers in robotics [60] as well as stents, sutures, implants etc for biomedicine [61].…”

Efficient split-step schemes for fluid-structure interaction involving incompressible generalised Newtonian flows

“…A moving or deforming solid, in turn, alters the fluid flow domain in return and therefore has a large impact on the flow quantities. Countless applications of FSI are found in science, engineering and biomedicine, ranging from airfoils or whole wind-turbines [1,2], bridge-decks [3], offshore engineering [4,5], insect flight [6] to blood flow through the circulatory system [7][8][9][10][11][12], human phonation [13] or breathing [14]. Consequently, the development of suitable numerical models and solution procedures has been an active area of research over the past 40 years, which led to great advances in the field.…”

“…In monolithic coupling schemes, all balance equations are considered in one single system of equations, assembling contributions from all involved variables into the same matrix. This leads to an inherent tight coupling of physical fields, but unfortunately comes with an increased implementation 1 Email address: schussnig@tugraz.at, corresponding author effort, possibly unusual data structures and more involved preconditioners. Several variants to enforce the interface conditions include, e.g., Langrange multipliers [8,[33][34][35][36], Nitsche's method [37][38][39], mortar techniques [28,40], penalty approaches [41][42][43] or formulations enforcing interface conditions via the function space choice [44][45][46][47][48][49].…”