Vorticity-Induced Effects in Wings over Waves- A Computational Study with Force Partitioning

Ground-effect aircraft (GEAs) offer significant advantages in naval operations, including increased aerodynamic efficiency and the ability to operate from water surfaces. However, operating in high sea states over transient, rough, wavy surfaces presents challenges, as large-amplitude waves can induce significant dynamic effects on the aerodynamics and stability of GEAs. Using time-accurate simulations via a high-fidelity sharp-interface immersed boundary method, we investigate ground-effect aerodynamics of a NACA 4412 airfoil at a chord Reynolds number of 100,000. First, a comprehensive parametric sweep for the wing over a flat surface is conducted to establish a baseline for aerodynamic performance across varying ground clearances and angles-of-attack. These results are compared against 3D simulations, as well as existing RANS and experimental data. To examine the effect of flight over waves, the study explores three wave configurations: a solitary wave crest, a solitary wave trough, and a sinusoidal wave. The results are subjected to a force-partitioning method-based analysis to quantify the effect of different vortex structures on aerodynamic performance.