Geometric model complexity effects on aircraft wake vortex parameters and structures

Accurate prediction of initial aircraft wake vortex parameters provides a foundation for wake turbulence separation optimization and efficient simulation. To clarify the impact of aircraft model complexity on the wake vortex generation and the resulting parameters and structures, numerical simulations are performed using four models: an isolated wing, an equivalent wing retaining the fuselage width, a wing incorporating fuselage, and a wing incorporating fuselage and empennage. Aerodynamic forces, surface pressure, vorticity magnitude, Q criterion fields, primary wingtip vortex spacing, circulation, and peak vorticity are compared. Results demonstrate that retaining the fuselage-width contribution through an equivalent-wing representation alters forces, whereas the empennage has little influence on the main wing pressure and forces under the present fixed-incidence, untrimmed condition with relatively small tail loads. Fuselage-induced pressure differences are mainly concentrated near the wing-body junction and inner wing, and gradually decrease toward the outer wing. Wake vortex structure analysis indicates that effective wingspan is the dominant factor governing the lateral position and spacing of the primary vortices. Omitting the fuselage width underestimates the primary vortex spacing by ∼3.9 m at x = 20 m and 3.6 m at x = 80 m, and reduces the downstream contraction ratio to 2.78%, compared with 3.36%–3.66% for models retaining the fuselage width. Under the same effective wingspan, the realistic fuselage and empennage exert limited influence on primary vortex spacing but introduce fuselage wake, wing-body junction vortices, and empennage-induced vortices, producing a more complex multi-source central wake structure. These results clarify the effects of aircraft model complexity on wake vortex parameters, structures, and near-field downstream development, providing a physical basis for aircraft geometry simplification and model selection in wake vortex studies.