Modeling and Testing of a Morphing Wing in Open-Loop Architecture

Abstract

This paper presents the modeling and experimental testing of the aerodynamic performance of a morphing wing in open-loop architecture. We show the method used to acquire the pressure data from the external surface of the flexible wing skin, using incorporated Kulite pressure sensors and the instrumentation of the morphing controller. The acquired pressure data are analyzed through fast Fourier transforms to detect the magnitude of the noise in the surface airflow. Subsequently, the data are filtered by means of high-pass filters and processed by calculating the root mean square of the signal to obtain a plot diagram of the noise in the airflow. This signal processing is necessary to remove the inherent noise electronically induced from the Tollmien-Schlichting waves, which are responsible for triggering the transition from laminar to turbulent flow. The flexible skin is required to morph the shape of the airfoil through two actuation points to achieve an optimized airfoil shape based on the theoretical flow conditions similar to those tested in the wind tunnel. Two shape memory alloy actuators with a nonlinear behavior drive the displacement of the two control points of the flexible skin toward the optimized airfoil shape. Each of the shape memory actuators is activated by a power supply unit and controlled using the Simulink/MATLAB® software through a self-tuning fuzzy controller. The methodology and the results obtained during the wind-tunnel test proved that the concept and validity of the system in real time are discussed in this paper. Real-time acquisition and signal processing of pressure data are needed for further development of the closed-loop controller to obtain a fully automatic morphing wing system.

Design of adaptive transonic laminar airfoils using theγ-Re˜θttransition model

“…In total, 24 data points were taken using the infrared thermography and are used here as validation test cases. More details on the experimental procedure can be found in [21].…”

Analysis of the Aerodynamic Performance of a Morphing Wing-Tip Demonstrator Using a Novel Nonlinear Vortex Lattice Method

“…Eight different surface grids of increasing mesh density were generated for each of the geometries, each grid having a constant spacing in both chord-wise and span-wise directions. The total number of cells for the wing semi-span generated 13 for each of the eight grids, as well as the chord-wise number and span-wise number are presented in Table 2. In Figure 1 Thus, the calculation times can be significantly further reduced by performing the strip calculations in parallel mode, or by using airfoil experimental performance databases instead of running the two-dimensional solver.…”

“…Two control approaches were used for providing the optimal SMA actuator displacements for each different flight condition. In the open loop configuration, the desired displacements were directly imposed on the system [13], while a novel, adaptive, neuro-fuzzy approach which was used to predict and control the morphing wing performance [14]. In the closed loop configuration, the displacements were automatically determined as a function of the pressure readings from the wing upper surface [15]- [16].…”

Numerical simulation and wind tunnel tests investigation and validation of a morphing wing-tip demonstrator aerodynamic performance

“…In the open-loop configuration, the desired displacements were directly imposed on the system [25], while a novel, adaptive, neurofuzzy approach which was used to predict and control the morphing wing performance [26]. In the closed-loop configuration, the displacements were automatically determined as a function of the pressure readings from the wing upper surface [27,28].…”