Experimental observation of vortices in wing-body junctions

Abstract

Tests have been made on various wing-body combinations to investigate the nature of the flow in the junction. It was found that vortices are formed due to separation of the boundary layer on the body in the flow towards the wing. The free edge of the resulting vortex sheet rolls up to form the vortex which then trails downstream around the wing. As incidence is increased the vortex on the suction side of the wing moves towards the wing and the vortex on the pressure side moves away from the wing. The vortices are present with both swept and unswept rounded leading edges at subsonic and supersonic speeds but were not found with sharp leading edges at zero incidence.