Effects of vibrating and deformed trailing edge of a morphing supercritical airfoil in transonic regime by numerical simulation at high Reynolds number

摘要

This article examines the aerodynamic performance increase of an Airbus A320 aerofoil thanks to morphing of the near-trailing-edge region in transonic regime corresponding to cruise conditions. The study has been carried out by numerical simulation at Reynolds number Re = 2.06 x 10(6) and Mach number of 0.78, by using the NSMB code (Navier-Stokes MultiBlock) including adapted turbulence modelling approaches sensitised in capturing coherent structures development. It has been shown that transonic buffet occurs at angle of incidence 1.8 degrees and in a more pronounced way at angle of 5 degrees. The interactions among the shock-boundary layer area, the shear layers vortices and those of the near wake have been analysed by spectral analysis and streakline dynamics. Strong feedback effects have been shown from the near trailing-edge region towards the SWBLI (Shock Wave Boundary Layer Interaction) up to the upstream of the shock area. By taking benefit from these feedback effects, it has been obtained that morphing applied as a slight upwards deflection of the near-trailing-edge region by 2 degrees is able to practically attenuate the buffet instability and to increase lift-to-drag ratio by 10.4 percent. The trailing-edge's area vibration at low amplitudes simulating the motion of piezo-patches of MFC type (Macro-Fibre Composites) applied experimentally in the context of the H2020 European research project www.smartwing.org/SMS/EU) has shown a lock-in effect of the buffet's frequency. Therefore, a conditioning of the shock's motion by means of these actuations can be reached, although a relative increase of the rms of the aerodynamic forces is produced in this case. The study of a combined upwards slight deflection and of trailing-edge area vibrations allowed obtaining decrease of drag and increase of lift-to-drag ratio with simultaneous decrease of rms. These effects have been studied for a wide frequency range from 200 to 500 Hz. (C) 2019 Elsevier Ltd. All rights reserved.