Theoretical Investigation of the Aerodynamics of Membrane MAV Wings with Cambered Frames

摘要

This paper builds on a previous study that investigated aerodynamic properties for flexible membrane MAV (micro air vehicle) wings with cambered frames. The frames for the wings were designed in SolidWorks and fabricated using an Objet30 Pro 3D printer. The membranes are composed of silicone rubber. The wings were tested in a The University of Alabama's low speed wind tunnel at a Reynolds number of 50,000 (10 m/s) while varying angles-of-attack from -4 to 24°. In the previous study, results showed that cambering the frames for the low aspect ratio (AR = 2) flexible MAV wings increases maximum lift and aerodynamic efficiency when compared to flat frames. In this study, lifting-line theory was used to perform a theoretical analysis on the time-averaged shapes for the membrane wings. The calculated values were compared with the experimental values to determine the effectiveness of using the theory for approximating time-averaged aerodynamic coefficients. It was determined that lifting-line theory approximates the lift coefficients reasonably well despite the assumptions of inviscid, attached flow, while also indicating higher relative induced drag for frames with less camber and at larger angles-of-attack.