Thesis: Physical analysis of electroactive morphing concepts for the aerodynamic performance increase of future wing design through High-Fidelity numerical simulation and turbulence modelling in high Reynolds number

PhD defense: Abderahmane MAROUF

Title: Physical analysis of electroactive morphing concepts for the aerodynamic performance increase of future wing design through High-Fidelity numerical simulation and turbulence modelling in high Reynolds number

Team: MécaFlu

Abstract: This thesis aims at investigating efficient concepts for morphing wings design in different scales (reduced and near scale one), in the subsonic regime and at different stages of the flight. The study has been carried out by High-Fidelity numerical simulations using adapted turbulence modelling closures able to sensitise the coherent structures development. A special attention is paid to the fundamental mechanisms and physical understanding of the flow around the wing and their modification when the morphing is activated. Electroactive morphing concepts are implemented in the Navier Stokes MultiBlock (NSMB) solver and a large parametric study concerning the actuation frequencies and amplitudes has been accomplished in a similar way in synergy with the experimental studies in the H2020 European research project SMS, "Smart Morphing and Sensing for aeronautical configurations". The morphing concepts investigated in this thesis concern the effects of near trailing edge actuation and low deformation in the frequency range of (30 - 400) Hz by means of piezoactuators, as well as by high deformation cambering (as in experiments through Electromechanical or Shape Memory Alloys actuations), in low frequency (order of 1Hz) and finally, by associating both, in the context of hybrid electroactive morphing. The considered prototypes have been those of the SMS project, the Reduced scale (RS) and the Large Scale (LS) two element wing-flap high lift prototype of an A320 wing. Two- and three-dimensional simulations were carried out using adopted turbulence modelling approaches as the Organised Eddy Simulation OES model and Hybrid methods as the Detached Eddy Simulation, to reveal the surrounding turbulence and the wake’s coherent structures as the Kelvin Helmholtz and von Kármán vortices leading to the alternating vortices in the wake using spectral analysis. These models have been able to capture the morphing effects through the actuations and to provide the aerodynamic performance increase. It has been shown that optimal trailing edge vibrations are able to suppress the three-dimensional motion in the wake and to lead to a lift increase of +4.28 % and lift-to-drag of +1.61 % on the RS prototype. An optimal vibration has been studied in case of the LS high lift prototype and provided a lift increase of +0.55 % together with noise sources reduction past the trailing edge of -15 to -20 dB. An optimal cambering system has been derived and studied for the LS prototype, being near full scale and leading to a lift-to-drag performance of +3.26 %. These benefits have been studied in the case of a full A320 aircraft and provided a +2.24 % lift-to-drag increase. Finally the simultaneous and bio-inspired association of the cambering and the trailing edge vibrations in the hybrid electroactive morphing context, revealed a -0.71 % of drag decrease, leading to a considerable augmentation of lift-to-drag ratio of +0.50 % compared to only cambering. These investigations have been carried out in the H2020 N° 723402 European Research programme SMS project.

The jury is composed by Prof. Yannick HOARAU (Professeur, Directeur du département Mécanique, ICUBE, Université de Strasbourg), Dr. Marianna BRAZA (Directrice de recherche CNRS, Institut de Mécanique des Fluides de Toulouse IMFT), Prof. Frank THIELE (Rapporteur, Technische Universität Berlin, Allemagne), Prof. Yiannis VENTIKOS (Rapporteur, Director of the Mechanical Engineering Dept, University College London, Angleterre), Prof. Henda DJERIDI (Examinateur, INP de Grenoble, France), Dr. Denis DARRACQ (Examiateur, AIRBUS Toulouse, France) and Dr. Flavien BILLARD (Examinateur, DASSAULT Aviation, France).

The defense will be held in English, on October 15th at 10am in the Alain Beretz amphitheater at the new Patio on the Esplanade Campus. The number of places in the room being limited, taking into account the respect of rules related to the sanitary situation, if you wish to attend the defense, please send an email directly to Abderamane Marouf to get the registration link.

Keywords: Aérodynamique, Modélisation de turbulence, CFD, morphing des ailes.