Numerical Investigations on Low-Speed Aerodynamic Characteristics of Generic Unmanned Combat Aerial Vehicle Configurations

The leading-edge sweep angle significantly influences the flight performance of swept wings. The vortex flow structures affect the flow behavior of the moderate to highly swept wings, which form at low angles of attack because of leading-edge flow separation. This topic of investigation gained momentum due to its application to unmanned combat aerial vehicle (UCAV) configurations that are significantly affected by flow separation at high angles of attack. The present work investigates the flowfield and low-speed aerodynamic characteristics of the generic UCAV models with a constant and nonconstant leading-edge sweep for a wide range of angles of attack. The open-source computational fluid dynamics code OpenFOAM 8.0 is employed for the numerical simulations. The present numerical simulation results agree well with the experimental data in the literature. It is demonstrated that the lift and drag characteristics of the UCAV are sensitive to the leading-edge sweep angle, and a nonconstant leading-edge sweep angle variant exhibits delayed stall and enhanced aerodynamic performance.