A2 Gradient Plumage

Title

A2 models the aerodynamic degradation produced by damage to the plumage, regardless of its cause: ectoparasites (lice, mites) that destroy the microstructure of the barbules, incomplete molt that leaves gaps in the wing, abrasion wear at the end of the breeding season, or hydrocarbon contamination that clumps the feathers. The wing of a bird is an active and morphologically complex airfoil (E2); Its degradation acts in three simultaneous ways: it increases the surface roughness (advances the laminar-turbulent transition, increases C_D), reduces the integrity of the slots between primary remiges (increases the induced wingtip drag), and can decrease the effective area (reduces C_L_max). The model quantifies these three pathways from a degradation rate I_deg measurable in the field by photography, and propagates their effects to the full drag polar and the P(V) curve.

ID:4212