Aerodynamic Performance of Lambda Wing-UCAV at Different Back-sweep Angles

Abstract

Unmanned Combat Aerial Vehicles (UCAVs) are designed to be lightweight and compact, which can impact their overall lift and aerodynamic capabilities. This study focuses on enhancing the Coefficient of Lift (CL) by optimising the Back Sweep Angle in the Lambda wing-UCAV. The model's baseline geometry remains unchanged during the experimental and numerical analysis, while different back sweep angles ranging from δ=0° to δ=50° are investigated at varied free-stream velocities and angles of attack. This helps to understand the generation of induced lift in the intricate shapes of the Lambda Wing. The results indicate a 5% to 10% increase in the lift for every 10° increments of the Back Sweep Angle, and the vortices' strength increases and reaches a maximum at δ=40°. At greater angles (δ?>40°), the lift drops gradually with the Reynolds number. The stagnation point shifts from 25% to 35% along the chord towards the pressure surface as the angles of attack increase from α=5° to α=10°. The angle of attack α>10°.