Optimal Sizing and Cruise Speed Determination for a Solar-Powered Airplane

Abstract

This paper presents the use of a genetic algorithm to optimize the size and cruise speed of a solar-powered unmanned aerial vehicle named Xihe. A conceptual aerodynamic configuration design is conducted first to obtain the initial size of the aircraft and the performance parameters. The optimization process then searches for optimal solutions for minimum energy operation. To minimize the number of decision variables, the aspect ratio of the wing and the fuselage design are fixed during optimization. The mass of the Xihe aircraft is then parameterized as a function of two performance parameters: wing reference area and cruise speed. With the parameterization results, a fitness function that links the optimization problem and the genetic algorithm is then established. The genetic algorithm searches for the optimal results for minimum energy operation. This optimization process reduces the referenced wing area of the Xihe aircraft from 5:63 m 2 in the conceptual design to 4:91 m 2 , which allows the reduction of the solar cell panel by 12.79%, reducing the costs. Optimization reduces the mass of the aircraft from 24.96 to 22.47 kg: a 9.98% reduction. The cost of the complex materials used would be less than originally required, and the cruise speed would increase from 10.93 to 11:23 m=s (the cruise speed for minimum power consumption).

Reviews of methods to extract and store energy for solar-powered aircraft

“…Shiau and Ma [77] realize this problem and jointly optimize the design-parameters and cruise speed during level flight to design a solar-powered aircraft. For the case they studied, the optimization reduces the mass of the aircraft and increases the cruise speed simultaneously.…”

“…Year Type of BATTERY Specific energy (W h/kg) Solar Impulse HB-SIA [74] 2009 Lithium-ion polymer battery, weigh 400 kg, or more than 1/4 of the total mass of the plane 240 Sunrise II [75] 1985 Lithium-ion polymer battery 145 Xihe [77] 2009 Lithium-ion polymer battery 196 Green flight challenge:…”

PV System Design and Flight Efficiency Considerations for Fixed-Wing Radio-Controlled Aircraft—A Case Study

“…For instance, solar cars are used widely for transportation in common life [3]. For traveling across large distances, PV powered airplanes are used [4][5][6]. At the beginning of the 21st century, solar cells were generally proposed for stationary applications, mostly on flat roofs [7].…”

“…After that, the target became continuous manned flight, which was accomplished with Solar Impulse in 2010 [5,14,20]. Today, UAVs are widely available with applications in telecommunications, agriculture, meteorology, border control, ocean observation and military applications [6,37]. At this point, it is hard not to mention the Aquila project [38] solar powered UAV, which has a wingspan as big as a Boeing 737 and can stay in the air for the months.…”

Fuzzy Controller for a Voltage-Regulated Solar-Powered MPPT System for Hybrid Power System Applications

“…Solar power could potentially redefine the endurance capabilities of UAVs because sunlight is an inexhaustible energy source. Since the successful flight of the first solar-powered aircraft, Sunrise [3], in 1974, designing solar-powered aircraft has been a topic of interest for the general public and UAV communities [4][5][6][7][8][9]. Solar-powered airplanes are used in developing scientific technology and for commercial exploitation purposes.…”