Impact of Ground Proximity on an Inverted Delta Wing

Abstract

The impact of ground proximity on the aerodynamics and trailing vortices of an inverted delta wing was investigated experimentally. The ground proximity always led to a lift and drag increase compared to their outside ground-effect counterpart. The largest lift increment occurred in the low-incidence regime but decreased nonlinearly with increasing incidence. A 145% lift increment for a ground distance of 0.5% chord at 3° incidence was obtained. The ground effect also led to an enlarged trailing vortex with increased rotational speed and vortex strength but a lowered peak vorticity. The trailing vortices moved further outboard with reducing ground distance. The results suggest that winged ground-effect vehicles with an inverted delta-wing planform can benefit from the ground effect for a ground distance up to 40% chord.