Morphing of a supercritical wing by means of trailing edge deformation and vibration at high Reynolds numbers: Experimental and numerical investigation

Abstract

This article examines the morphing effects of the trailing-edge deformation and vibration on the turbulent structures in the wake of a supercritical Airbus-320 wing. It is shown that the electroactive morphing has the capacity to produce an enhanced aerodynamic performance (lift increase, drag reduction) and reduce the amplitude of instability modes associated to aerodynamic noise. The appropriate actuation is achieved with piezoactuators placed in the trailing edge region. The work presented has been carried out numerically using the Navier-Stokes Multi Block (NSMB) code, as well as experimentally with measurements obtained in the S4 wind tunnel of IMFT by means of TRPIV (Time-Resolved PIV) with a sampling rate around 10 KHz. The Reynolds number is 1 Million. The study is carried out in the low subsonic regime at an incidence angle of 10 • , corresponding to take-off/landing flight phases and analyses significant morphing effects obtained by optimal deformations and vibrations of the near trailing edge region. The interactions that are prompted in the wake region are analyzed by means of Proper Orthogonal Decomposition (POD), considering the near wake structure in respect of the morphing effects. The effects on the aerodynamic coefficients thanks to manipulation of specific vortex dynamics in the shear layers and the wake are discussed and optimal frequency/amplitude ranges for the vibrations are quantified.

A parametric study of the effect of self-oscillating trailing-edge flaplets on aerofoil self-noise

“…Low turbulence levels mean less tonal noise and vice versa. In a recent study from Yu and Yang [33] it was shown that an oscillating trailing edge fringe is able to reduce the strength and size of the shed vortices, similar as observed for an active oscillation of the trailing edge reported by Simiriotis et al [34]. A flaplets, the short flaplets were also extremely effective at Re c > 600, 000.…”

“…While the analytical approach was able to determine multiple frequencies that could be reduced, their experimental results revealed only a single zone where the reduction is observed, similar to the results herein. We would like to point out that it cannot be excluded from their experiments that small vibrations existed, especially as the herein observed acoustic effect is already visible for vibration amplitudes as small as 100-200 µm (compare also the study with active oscillating flaplets with a similar effect at similar oscillation amplitudes, see Simiriotis et al [34]). Furthermore, their noise reduction was focusing on the broadband noise while the flaplets herein clearly address the tonal noise components.…”

Effect of different geometries of self-oscillating trailing-edge flaplets on aerofoil self-noise

“…They also showed that the lift coefficient was increased and drag coefficient was reduced, and this was attributed to the creation of a suction region downstream of the fringe. In a similar manner, active oscillations of a trailing edge flap were studied by Simiriotis et al [22]. Their investigation was focused on the wake structure and it was observed that the wake could be reduced in thickness by as much as 10%.…”

CFD simulations of active flow control devices applied on a cambered flap

“…For unsteady CFD simulations Hybrid RANS-LES models are available as well as the k-𝜖 Organized Eddy Simulation model [20,21] which were used for 2D and 3D simulations. The Arbitrary Lagrangian Eulerian (ALE) approach is employed for simulations using moving or deforming grids employed in morphing simulations ( [22,23]). NSMB includes a re-meshing algorithm that is a combination of Volume Spline Interpolation (VSI) [24] and Transfinite Interpolation (TFI).…”