# Design, Manufacturing, and Flight Testing of an Experimental Flying Wing UAV
## 1 Introduction
Sunlight is considered inexhaustible, and solar-powered UAVs can be in continuous flight in theory if they do not require maintenance. Therefore, many researchers have focused on solar-powered aircrafts. [PERSON] presented a methodology for the conceptual design of a solar-powered aircraft [11]. They combined a Roskam-style parameter formulation with [PERSON]'s solar power notation. This provides a design methodology that is useful and easy to understand. Recently, genetic algorithms were used for optimizing aerodynamic configuration designs. Many studies have focused on optimizing aerodynamic configurations and the efficiency of evolutionary computational algorithms. The tendency to get trapped in local minima is a shortcoming in conventional gradient-based optimization techniques. Genetic algorithms are more efficient than conventional gradient-based optimization techniques. An optimal sizing method based on genetic algorithms, minimum power cruising speed, and mass parameterization was developed [12]. Another study presented an aerodynamic performance design of a solar-powered aircraft and its solar power management system design [13]. This design and system were verified through successful ground and flight tests, making this Taiwan's first solar-powered UAV. [PERSON] [14] noted that fuel burn reduction is an important issue in aircraft design research, especially in civil aviation. To use an unconventional aircraft configuration, such as the flying wing, is a possible way to reduce fuel burn, but the design of flying wing is accompanied by new challenges. The strong coupling between aerodynamic performance and stability is not easy to handle in the flying wing design. They believe that numerical optimization is useful to find the best possible flying wing configuration. Later, [PERSON] presented a multidisciplinary design optimization study of an electric flying wing [15]. A powered wind tunnel testing of the hybrid wing body (HWB) was completed by Lockheed Martin (LM) and the Air Force Research Laboratory (AFRL) [16]. A subscale aircraft model was built and the test data was compared with computational fluid dynamic (CFD) simulations. The basic aerodynamic performance was validated in this study. Considering the characteristics and constraints of electric-powered aircrafts, this study proposes a new integration method for electric-powered aircraft conceptual design. We report on the design, manufacturing, and flight testing of an electrically powered experimental flying wing UAV. The matching plot is a method for preliminary aircraft design that converts aircraft performance requirements into a wing loading (W/S) and thrust-to-weight ratio (T/W) or power loading (W/P) function and then finds the appropriate wing loading and thrust-to-weight ratio or power loading. Appropriate values are obtained from the intersection of the wing loading and thrust-to-weight ratio or power loading that can satisfy all performance requirements in the matching plot. In the second section, the performance requirements of the electric-powered UAV are defined as the stall speed, maximum flight speed at cruising altitude, absolute ceiling, and turning radius and speed. Then, a matching plot is used to find the appropriate wing loading and power loading. In the third section, we propose estimating the UAV weight using the flight time and payload. The UAV's wing area and power requirements can be calculated from its weight and appropriate wing loading and power loading. Therefore, the UAV's motor specification can be well defined with the power budget. In the fourth section, airfoil selection, aerodynamic design, and stability design are considered, and these parameters are associated with the UAV's wing area. In the fifth section, the manufacturing procedures for the electric-powered experimental flying wing UAV are reported. After design, composite materials are used to build the flying wing UAV.