Modeling and Analysis of an Ultra Light Slow Flyer With Variable Shape Control Surfaces Using Shape Memory Alloy Actuators

Applying flexible variable shape control surfaces (wing and elevator) structures is a way to increase efficiency and maneuverability of the planes, which is recently under research. In this paper, modeling of the flight of an unmanned ultra light plane is discussed. The modeling is done based on a real ultra light plane presented recently. To increase maneuverability of the plane, flexible variable shape structures are designed for the wing and the elevator. In design procedure, having an ultra light plane is considered. The elevator and the wing are used as control surfaces for longitudinal and lateral maneuvers respectively. Shape memory alloys (SMA) are used for reshaping the flexible structures of the wing and the elevator. Because of its high power and low weight and nearly unlimited resolution, SMA is best suited as the actuator of the reshaping wing and elevator structures. In flight dynamic modeling of an ultra light plane with variable shape wing, aerodynamic coefficients are needed. Coefficients are computed using computational fluid dynamics (CFD). To determine the reshaped structures, finite element models of structures are constructed in ANSYS^®. Using finite element analysis (FEA), reshaped structures are produced and transferred to FLUENT^® for CFD analysis. Aerodynamic coefficients with respect to reshaped structures are computed and related to actuator forces as functions. Also, aerodynamic coefficients and their derivatives with respect to flight parameters, like the angle of attack and the angular velocities are computed. Finally, the results are combined for the complete simulation in MATLAB/Simulink^®.