Wind tunnel testing of a ducted-fan unmanned aerial vehicle

Abstract

This report has investigated the effects of the aerodynamic parameters of lift, drag, moments and thrust and determined their relationships with different wingspans at different pitch and wing incidence angles on a ducted-fan Micro Air Vehicle (MAV) at a speed of approximately 15m/s. The experiments were carried out in a closed-loop wind tunnel with the full-scale MAV at different configurations.

Coefficients of lift, drag and pitching moment were first discussed in a simple configuration of varying pitch angle with different wing setups without the propeller motor. Wings were maintained at the same pitching angle horizontally with the duct and changes in these coefficients were analyzed. It was observed that wings naturally provide better lift performance at the expense of drag and stall angle.

Hence, the lift-drag ratio (L/D) was then compared to determine the efficiency of the MAV. The static longitudinal stability was also analyzed through the relationships of the pitching moment coefficients. The experiment was then further extended to varying pitching and wing incidence angles together. Wing incidence angles were varied at different duct angles to understand the effects of interference between the two. The results were then presented similarly in coefficients of lift, drag and moment.