This paper will detail the aerodynamic design of a small unmanned box-wing aircraft to facilitate the study of turbulence by Dr. Brian Argrow at the CU Boulder. A design with no fuselage was necessary for the data collection, which presented a longitudinal stability challenge. The key to eventually achieving a stable design was weight placement for positive static margin. This paper will include the design process used to confront these issues. The initial choices of stagger, gap, decalage, and relative sweep are made using a simple model leveraging previous box-wing research. These, as well as the airfoil selection, are then investigated further using Athena Vortex Lattice (AVL) to analyze lift, drag, and stability. The final airframe design has a gap and stagger of 1 chord length, decalage of 5 degrees, and relative sweep of 30 degrees. A cambered NACA 6412 airfoil on the top wing and a reflexed NACA23112 airfoil on the bottom wing are selected, which combine to induce a positive pitching moment and aid in longitudinal stability. The resulting box-wing aircraft was flight tested successfully and will serve as an ideal platform for research at CU Boulder.

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