Towing tank investigation on wake vortex ground linking and the influence of final height above ground

A series of experiments were conducted in a towing tank to better understand the interactions between wake vortices and the ground during the final approach of a wing at different final heights above ground. The study employed a model with an adjustable angle of attack and a simplified ground-approaching trajectory. Earlier numerical experiments have already described the phenomenon of vortices connecting to the ground, commonly known as ground linking. The experimental data presented in this study corroborate the description of ground linking provided by other researchers. Furthermore, increasing the wing’s final height above the ground increased the time the vortices took to link to the ground. Vortices displayed varying characteristics at final heights of one chord and one spanwise length. The former quickly link to the ground, while the latter, the left and right vortices link to form a horseshoe vortex before linking to the ground. While understanding these vortex patterns is crucial for further experimental research on wake vortices, the experiment’s results at a realistic final height of one chord length provide insights into the vortex characteristics and time development, both of which are fundamental for evaluating their hazards at airports. •Vortex ground linking measurement and parameterized description.•Vortex ground interaction and dependence on the final height above ground.•Horseshoe vortex and ground interaction.•Horseshoe vortex decomposition and multiple vortex linking to the ground.