Toward perpetual flight: conceptual and preliminary development of the DELICE-1A UAV
This paper presents the design, aerodynamic analysis, manufacturing, and energy feasibility assessment of DELICE 1A, a 5 m-wingspan solar-electric unmanned aerial vehicle (UAV) developed as a technology demonstrator toward high-altitude pseudo-satellite (HAPS) operation. The MO6070 airfoil is evaluated using XFLR5 batch analysis and ANSYS Fluent CFD at Reynolds numbers between 100,000 and 500,000, yielding L/D = 19.7 at the design cruise point. Propulsion performance is characterised at sea-level conditions, giving a required power of 89.25W at 14.9ms−1. A sinusoidal irradiance model calibrated for the summer solstice at Ankara (Tday = 14.84 h, Imax = 945Wm−2) is used to evaluate two solar coverage scenarios. In Scenario A, 80 SunPower C60 cells on the main wing (A = 1.20m2) extend endurance from 4.06 h to 5.94 h, a 46.2% gain. In Scenario B, 180 cells covering the main wing and horizontal tail (A = 2.70m2) reduce the irradiance threshold to 248Wm−2 and yield 4.58 h endurance. These findings showcases that not only panel area is the critical constraint for perpetual flight at this scale, but higher battery energy density and more efficient solar cells, and lighter structures should also be provided. These findingd establishes quantitative energy targets for the next design iteration on DELİCE-2.