This is a simple visualization on ANSYS Post using Fluent solver, of a symmetric airfoil delta wing (airfoil NACA0085, taper ratio of 0.1) at a high angle of attack of 20°. The primary vortex separates at the leading edge itself unlike for other wings. Also unlike for conventional rectangular wings the vortex creates lift by reattaching to the upper surface, whereas a vortex is always detrimental for lift for conventional wings. This enables delta wings to evade stall even at 35° angle of attack. The reattachment is seen mainly for streamlines at the mean chord.