3. Aerodynamic Analysis of Short Landing Solar-Powered UAV for Environmental Monitoring Applications

Solar-powered unmanned aerial vehicle (UAV) is a state-of-the-art technology which becomes widely popular in many fields of technology such as energy industry and aerospace industry. Several solar-powered UAVs have been developed with the aim to enhance flight endurance using various types of solar cells to extract and convert solar energy to electrical energy for onboard consumption. Large-scale solar-powered UAVs with appropriate design flying under appropriate environmental condition may have on-board energy storage system to extend flight endurance or to operate perpetually. The large-scale AtlantikSolar solar-powered low-altitude UAV, for example, demonstrated the potential to perpetually fly over day and night with an endurance of up to 28 hours.

According to significant development in solar photovoltaic technologies, small-scale solar-powered UAVs are becoming popular for long-endurance operations. However, this study aims to bring existing technologies to develop small solar-powered UAVs to operate at a low altitude. The solar cell technologies were studied and the aircraft performance analysis was performed to determine the design configuration which provides the optimum flight performance within the target operational wind speeds of 0–5 m/s. In addition, high angle-of-attack landing was also studied to determine the feasibility of short landing operation in a limited area. The calculation and flight testing indicated that the tailing elevator deflection at a certain −30 deg enabled a deep stall trajectory without any damage to the vehicle.