Design and Performance Estimation of a Low-Reynolds Number Unmanned Aircraft System

The purpose of this thesis is to conceptually design a fixed-wing unmanned aircraft systems (UAS) with a higher flight-time and top stable speed than comparable systems. The vehicle adheres to specifications derived from the client, the market, and the Federal Aviation Administration (FAA). To broadly meet these requirements, the vehicle must fly for a minimum of three hours, return to the original flight path quickly if perturbed, and must be hand-launched. The vehicle designed must also have a large potential center of gravity movement to allow for customization of the planform and client customization. An iterative design process was used to quickly perform tradeoff analysis and to refine the overall design. Analysis is split into two categories: flight mechanics, and structural analysis. Flight mechanics determines the flight regimes in which the vehicle is assumed to fly and the aerodynamic load factors used in structural analysis (up to 3.8 times the level flight loading. The change in lift due to skin deflection is determined to be negligible under maximum gust conditions. The vehicle itself is stable in all flight conditions, except the spiral mode; however, the addition of a stability augmentation system (SAS) can allow for corrections and autonomous flight in future iterations. The vehicle can operate between sea-level and a maximum flight altitude of 10,400 ft as required by the FAA in 14 CFR Part 107. The final flight time of 24 hours comparable to high-end UAS sold in the U.S. Further, the vehicle is stable in speeds up to 100 mph, allowing for the maximum legal speeds of travel