Energy efficiency improvement potential of a tactical BWB UAV using renewable energy sources

The current study presents the energy efficiency improvement potential of a Blended-Wing-Body (BWB) Unmanned Aerial Vehicle (UAV) with the implementation of alternative energy sources. A fixed-wing, tactical BWB UAV experimental prototype, which operates on fossil fuel and has been developed for the aerial delivery of cargo and lifesaving supplies as well as surveillance missions, is used as a reference platform. Two alternative propulsion systems, a hybrid-electric and an all-electric, are investigated in this work, by taking into account the required modifications, additional equipment and auxiliary systems, on a conceptual design level. A solar irradiation estimation model is used to calculate the solar power available, whereas an aerodynamic analysis is conducted, using Computational Fluid Dynamics (CFD) modeling, to estimate the required power. The selection and sizing of the corresponding systems is then made, by assuming that the external configuration layout remains the same. Finally, the three configurations, i.e. the conventional, the hybrid-electric, and the all-electric, are compared in terms of Gross Takeoff Weight (GTOW) and power consumption, so that an assessment of the use of renewable energy sources can be carried out.