Andreea Koreanschi

Low-speed aerodynamic characteristics improvement of ATR 42 airfoil using a morphing wing approach

This paper presents a morphing wing technique for extending laminar flow over the airfoil of the ATR 42 regional transport airplane. The objective is to reduce aerodynamic drag by delaying the transition from laminar to turbulent flow over the airfoil upper surface. The optimization of the airfoil shape is performed for several incompressible subsonic regimes, using a genetic algorithm tool, coupled with the subsonic aerodynamic solver XFOIL. A reduction of the drag coefficient with up to 26.73% and a delay in the transition point of up to 24.81% has been achieved.

DESIGN AND VALIDATION OF A POSITION CONTROLLER IN THE PRICE-PAÏDOUSSIS WIND TUNNEL

Conventional or brushed DC motors are often used for many industrial applications. A large variety of these motors is found in automation, medical, robotics and aeronautical fields. In this paper, the design and experimental validation of a position controller for a morphing wing design application is presented. Matlab/Simulink was used to design the Proportional Integral Derivative controller. For experimental validation, tests were carried out in the Price-Paidoussis subsonic blow down wind tunnel. The upper wing surface was deformed by means of a mechanical system consisting of two eccentric shafts. Both are connected to electrical actuators. Comparisons of two sets of results are provided in this paper. The first set is related to control validation and the second set is related to aerodynamic validation.

Aerodynamic performance improvement of the UAS-S4 Ehecatl morphing airfoil using novel optimization techniques

In this paper, we present a morphing wing concept of the airfoil of the S4 unmanned aerial system, the new optimization methodology and the results obtained for multiple flight conditions. The reduction of the airfoil drag coefficient has been achieved using an in-house optimization tool based on the relatively new Artificial Bee Colony algorithm, coupled with the Broyden–Fletcher–Goldfarb–Shanno algorithm to provide a final refinement of the solution. A broad range of speeds and angles of attack have been studied. An advanced, multi-objective, commercially available optimizing tool was used to validate the proposed optimization strategy and the obtained results. The aerodynamic calculations were performed using the XFOIL solver, a two-dimensional linear panel method, coupled with an incompressible boundary layer model and a transition estimation criterion, to provide accurate estimations of the airfoil drag coefficient. Drag reductions of up to 14% have been achieved for a wide range of different flight conditions, using very small displacements of the airfoil surface, of only 2.5 mm.

Improving the UAS-S4 Éhecal airfoil high angles-of-attack performance characteristics using a morphing wing approach

In this paper, a morphing wing approach with a new methodology and its results for the high angles-of-attack optimization of the S4 unmanned aerial system airfoil are described. The boundary layer separation delay, coupled with an increase of the maximum lift coefficient, was achieved using an in-house optimization tool based on the artificial bee colony algorithm, coupled with the Broyden–Fletcher–Goldfarb–Shanno algorithm to provide a final refinement. The obtained results were validated with an advanced, multi-objective, commercially available optimizing tool. The aerodynamic calculations were performed using a two-dimensional linear panel method, coupled with an incompressible boundary layer model and a transition estimation criterion. For very small displacements of the airfoil surface, of less than 2.5 mm, lift coefficient increases of up to 18% together with relevant drag reductions have been achieved, successfully delaying separation for the high angles-of-attack range.

Flutter analysis of a morphing wing technology demonstrator : numerical simulation and wind tunnel testing

As part of a morphing wing technology project, the flutter analysis of two finite element models and the experimental results of a morphing wing demonstrator equipped with aileron are presented. The finite element models are representing a wing section situated at the tip of the wing; the first model corresponds to a traditional aluminium upper surface skin of constant thickness and the second model corresponds to a composite optimized upper surface skin for morphing capabilities. The two models were analyzed for flutter occurrence and effects on the aeroelastic behaviour of the wing were studied by replacing the aluminium upper surface skin of the wing with a specially developed composite version. The morphing wing model with composite upper surface was manufactured and fitted with three accelerometers to record the amplitudes and frequencies during tests at the subsonic wind tunnel facility at the National Research Council. The results presented showed that no aeroelastic phenomenon occurred at the speeds, angles of attack and aileron deflections studied in the wind tunnel and confirmed the prediction of the flutter analysis on the frequencies and modal displacements.

Design and wind tunnel experimental validation of a controlled new rotary actuation system for a morphing wing application

The paper presents the design and the experimental validation of a position controller for a morphing wing application. The actuation mechanism uses two DC motors to rotate two eccentric shafts which morph a flexible skin along two parallel actuation lines. In this way, the developed controller aim is to control the shape of a wing airfoil under different flow conditions. In order to control the actuators positions, a proportional–derivative control algorithm is used. The morphing wing system description, its actuation system structure, the control design, and its validation are highlighted in this paper. The results, obtained both by numerical simulation and experimental validation, are obtained following the control design and its validation. An analysis of the wind flow characteristics is included as a supplementary validation; the pressure coefficients obtained through numerical simulation for several desired airfoil shapes are compared with those obtained through measurements for the experimentally obtained airfoil shapes under different flow conditions.

Application of a Morphing Wing Technology on Hydra Technologies Unmanned Aerial System UAS-S4

The paper describes the application of a morphing wing technology on the wing of an Unmanned Aerial System (UAS). The morphing wing concept works by replacing a part of the rigid wing upper and lower surfaces with a flexible skin whose shape can be dynamically changed using an actuation system placed inside the wing structure. The aerodynamic coefficients are determined using the fast and robust XFOIL panel/boundary-layer codes, as the optimal displacements are calculated using an original, in-house optimisation tool, based on a coupling between the relatively new Artificial Bee Colony Algorithm, and the classical, gradient-based Broyden-Fletcher-Goldfarb-Shanno (BFGS) method. All the results obtained by the in-house optimisation tool have been validated using robust, commercially available optimization codes. Three different optimization scenarios were performed and promising results have been obtained for each. The numerical results have shown substantial aerodynamic performance increases obtained for different flight conditions, using the proposed morphing wing concept.

Aerodynamic analysis of upper surface wing morphing efficiency for the S4 Éhecatl unmanned aerial system

This paper investigates the aerodynamic performance improvement of the Hydra Technologies S4 Unmanned Aerial System using a morphing wing concept. A part of the wings upper surface is morphed, as function of the flight condition, in order to increase the S4s lift-to-drag ratio. The wing airfoil shape optimizations are performed using a hybrid Artificial Bee Colony and Broyden-Fletcher-Goldfarb-Shanno algorithm, coupled to a two-dimensional viscous flow solver. The wing geometries are reconstructed based on the morphed airfoils, and three-dimensional computations are performed, including the effects of the fuselage and tail, using a panel method. The viscous drag is estimated using strip theory, empirical and experimental approximations. The optimizations and three-dimensional results are obtained for fifteen flight conditions, corresponding to cruise and surveillance flights at various altitudes. Comparisons are made between the original and morphed geometries, and identify the conditions for which significant lift-to-drag ratio improvements are obtained using the upper surface morphing concept.

Morphing wing application on hydra technologies UAS-S4

This paper presents the aerodynamic results of a morphing wing study performed on the UAS S4 Ehecatl from Hydra Technologies. Only the cruise phase of the aircraft was considered (constant altitude and constant speed). The difference, from an aerodynamic point of view, between the morphing wing and the original wing was emphasized by computing and comparing their longitudinal aerodynamic coefficients (drag and lift). The computation of the aerodynamic characteristics was done using tornado with the Vortex Lattice Method.

Numerical study of UAS-S4 Éhecatl aerodynamic performance improvement obtained with the use of a morphing wing approach

1 PhD Student, Department of Automated Production Engineering, 1100 rue Notre Dame Ouest, Montreal, oliviu.sugar-gabor.1@ens.etsmtl.ca 2 PhD Student, Department of Automated Production Engineering, 1100 rue Notre Dame Ouest, Montreal, andreea.koreanschi.1@ens.etsmtl.ca 3 Professor, Department of Automated Production Engineering, 1100 rue Notre Dame Ouest, Montreal, ruxandra.botez@etsmtl.ca 1 American Institute of Aeronautics and Astronautics Numerical study of UAS-S4 Ehecatl aerodynamic performance improvement obtained with the use of a morphing wing approach