Numerical investigations of formation mechanism about a dual leading edge vortex structure of a delta wing with medium leading edge sweep angle

A numerical investigation of the characteristics and evolution of the structure of the vortical flowfield was carried out on 50°delta wing. The comparison of results shows good agreement between experimental studies and the CFD predictions. In this paper, vortical flowfield were analysed and summarized. The results indicate that a dual leading edge vortex structure is observed under some Reynolds numbers and angles of attack for a delta wing of the medium leadingedge sweep angle. The formation of the dual vortex structure of a delta wing is due to the relations among the velocity to the vortex core and the intensity of the separated shear layer that emanates from the leading edge of the delta wing. Generally speaking, a single leadingedge vortex structure is observed on the upper surface of the wing when the velocity to the vortex core is enough to carry off all the separated shear layer, otherwise the shear layer will branch and a dual leadingedge vortex structure will be formed.