Design of a Tandem-Wing UAV for Civilian Applications

Abstract

This paper presents the design of a tandem-wing UAV, emphasizing aerodynamics, propulsion, stability, structures and performance evaluation. It introduces a methodology for estimating UAVs' endurance, including weighted fractions. The aerodynamic coefficients and stability derivatives for the complete UAV were determined using the vortex particle wake (VPW) method in the Flow5 software. A mathematical model was constructed using state-space representation and the dynamic properties of the aircraft were assessed at its equilibrium position. A comprehensive stability analysis confirmed the UAV's stability in both static and dynamic scenarios. Structural analysis was performed on the airframe components by applying the discretized lift and drag forces. The design points utilized for the structural analysis were derived from the V-n diagram representing the flight envelope. Since the UAV does not have landing gear, a hand launch analysis was performed using MATLAB. The analysis determines if the UAV can take off safely with the desired payload under given conditions of launch height and initially imparted force. A prototype was built and successfully flight-tested, providing reassurance about the practicality of the design. The results shows that the designed UAV has a significant advantage over conventional UAVs in terms of low stall velocity and high payload fraction, demonstrating its superiority.