1
Master's student, .Ferdowsi University of Mashhad. Mashhad. Iran
2
Professor, Ferdowsi University of Mashhad
Abstract
Using a sinusoidal leading edge on a wing effectively controls flow and prevents flow separation from the wing surface. This study investigates the aerodynamic effects of introducing a sinusoidal leading edge on a lambda-shaped flying-wing UAV while keeping the wing area constant. The analyzed geometry features a wing with a 56-degree sweep angle and a -3-degree twist. The research employs numerical simulations using the Reynolds-averaged Navier–Stokes (RANS) equations solved through the finite volume method. The simulation process was validated with experimental data for angles of attack ranging from -5 to 20 degrees. Two key variables, the sinusoidal wave's amplitude and wavelength, were derived from previous experiments on similar UAVs. These parameters were selected to optimize the wing’s aerodynamic characteristics and improve vortex formation locations, especially at high angles of attack. The results indicate that applying a sinusoidal leading edge improves the lift-to-drag ratio by approximately 20% at attack angles between 5 and 15 degrees, leading to greater range and reduced fuel consumption. This research provides practical insights for the design and performance enhancement of UAVs. Additionally, the study shows that vortices form from each sinusoidal crest in a lambda wing with a sinusoidal leading edge, unlike flat-edged wings where vortices originate at the apex. This change in vortex structure may enhance lateral flow reattachment and delay flow separation at high angles of attack.
Hosseinikargar, A., Djavareshkian, M. H., & Madani, A. (2025). Investigating Effects of sinusoidal leading edge on a lambda-wing UAV at pre-stall angles. Fluid Mechanics & Aerodynamics, 14(1), 1-13.
MLA
Amir Hosseinikargar; Mohammad Hassan Djavareshkian; Afshin Madani. "Investigating Effects of sinusoidal leading edge on a lambda-wing UAV at pre-stall angles", Fluid Mechanics & Aerodynamics, 14, 1, 2025, 1-13.
HARVARD
Hosseinikargar, A., Djavareshkian, M. H., Madani, A. (2025). 'Investigating Effects of sinusoidal leading edge on a lambda-wing UAV at pre-stall angles', Fluid Mechanics & Aerodynamics, 14(1), pp. 1-13.
VANCOUVER
Hosseinikargar, A., Djavareshkian, M. H., Madani, A. Investigating Effects of sinusoidal leading edge on a lambda-wing UAV at pre-stall angles. Fluid Mechanics & Aerodynamics, 2025; 14(1): 1-13.
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