The Aerodynamics of a Maneuvering UCAV 1303 Aircraft Model and its Control through Leading Edge Curvature Change

This study investigates the aerodynamic effects of modifying the leading edge on an unmanned combat air vehicle (UCAV) 1303. Literature suggests that leading edge accelerations are reduced for rounder leading edges and stall characteristics are altered. These phenomena are examined using the previously tested 1/72 scale model with a 47-degree leading edge sweep and a cranked trailing edge delta wing with fuselage. The study consists of both flow visualization and aerodynamic force and moment measurements. The model is maneuvered in the NPS water tunnel where a five-component strain gage load balance system measures the forces experienced by it. The model is pitched at different rates with different degrees of yaw for these studies. This process is repeated for a modified leading edge with a radius double the baseline. Preliminary results show that the rounded leading edge acted as expected, alleviating signs of tip-stall in the normal force distribution and smoothing pitch-breaks in the pitching moment distribution. Rolling moment was shown to increase with angle of attack for the modified leading edge case.