Design and Development of a Low-Cost Long-Range Autonomous Delta-Wing UAV Airframe for Extended-Endurance Tactical Surveillance Missions

Abstract

This paper presents the design, aerodynamic sizing, propulsion–energy matching, simulation-based evaluation, and experimental validation of a low-cost long-range autonomous delta-wing unmanned aerial vehicle (UAV) airframe developed at the Nigerian Defence Academy Centre for Innovation and Creativity (NDA–CINOCRE) for endurance-class surveillance experimentation and indigenous aerospace research. The demonstrator employs a 52° moderate-sweep delta-wing configuration with a wingspan of 2.40 m and maximum take-off mass of 18 kg, optimised for low-Reynolds-number cruise efficiency and structural simplicity using hybrid foam–composite construction. Analytical modelling and computational fluid dynamics (CFD) simulations predicted a cruise lift coefficient of approximately 0.30 and peak aerodynamic efficiency of 𝐿/𝐷 ≈ 8.4at an optimum cruise speed of 24 m/s. Propulsion–energy matching indicated an endurance capability approaching two hours using lithium-ion battery storage. Ground testing and flight-envelope validation demonstrated close agreement between predicted and measured performance, including cruise power deviation of about 2.0%, lift coefficient error below 3.3%, and endurance deviation of approximately 3.5%. Sensitivity analysis further confirmed endurance prediction robustness within ±12% uncertainty bounds. The validated platform provides a scalable experimental baseline for persistent ISR research, autonomous navigation studies, launch-rail deployable UAV systems, and precursor long-range loitering-mission configuration development within the indigenous defence innovation environment.