A numerical approach to model and analyse geometric characteristics of a grey-headed albatross aerofoil in flight.

Limited research exists on the 3D geometric models and aerodynamic characteristics of the Grey-headed Albatross (GHA). Despite existing methods for extracting bird wing cross-sections, few studies consider deflections due to aerodynamic pressure. With the GHA known for its exceptional flight speed and purported wing-lock mechanism, it offers a valuable subject for studying fixed-wing aerodynamicsin nature. This study aims to develop and validate a numerical approach to estimate the GHA's wing cross-section in flight. The PARSEC method is combined with a scanned 3D point cloud of a dried GHA wing to create a 3D model and analyze an averaged aerofoil section. Using a pseudo-2D computational fluid dynamics model, the study explores passive morphing of bird wings due to aerodynamic pressure. Results show that the aerofoil morphs to achieve maximum potential aerodynamic efficiency at a Reynolds number of 2 × 105, decreasing in camber. The maximum lift-to-drag ratio (( / )max) increases from 3 to 44, primarily due to pressure drag reduction. However, the lack of comparison to true bird geometry in flight remains a limitation. Future research should compare the predicted morphing with actual bird specimens in flight. .