Real-Time Optimization of a Research Morphing Laminar Wing in a Wind Tunnel

This paper presents a new approach of real-time control of a morphing wing based on a coupled fluid-structure numerical model. The 2D extrados profile of an experimental laminar wing is morphed with the purpose to reduce drag, through extension of the laminar flow over the upper wing surface. As a first step, the active structure has been modeled, manufactured and experimentally tested under variable flow conditions in a subsonic wind tunnel (the Mach number ranges from 0.2 to 0.3 and the angle of attack from −1° to 2°). In this work, a real-time closed-loop control strategy is designed to find the optimum actuator strokes using an experimentally measured lift-to-drag ratio (feedback parameter). An extensive wind-tunnel characterization of the laminar wing prototype has been performed to design the algorithm and to set up the parameters. To calculate the initial strokes of the actuators and thus to accelerate the optimization procedure, a validated ANSYS-XFoil coupled fluid-structure numerical model is used. The robustness and efficiency of the developed real-time control system is tested under two flow conditions. The morphing wing performance obtained is slightly superior or similar to the open loop control approach proving the high performance of the numerical model. The proposed control strategy appears to be well suited to benefit from the complete morphing potential (according to the lift-to-drag ratio) of the wind tunnel prototype although higher feedback resolution is recommended from the numerical simulation algorithms.
ASME 2009 Conference on Smart Materials, Adaptive Structures and Intelligent Systems, September 21–23, 2009, Oxnard, California, USA
Series: ASME Proceedings