Unsteady vortex structure over a delta wing

The structure of the shear layer which emanates from the leading edge of a 76-deg sweep delta wing and forms the primary vortex is investigated numerically. The flow conditions are Mv_ = 0.2, Re = 50,000 and angle of attack of 20.5 deg. Computational results are obtained using a Beam-Warming-t ype algorithm. The existence of a Kelvin-Helmholtz-type instability of the shear layer which emanates from the leading edge of the delta wing is demonstrated. A description is provided of the three-dimensional, unsteady behavior of the smallscale vortices associated with this instability. The numerical results are compared qualitatively with experimental flow visualizations exhibiting a similar behavior.