Vortex flows over 50° sweep delta wing at low Reynolds number

The computational simulation and experimental investigation have been performed into the vortex structure over a non-slender delta wing with leading edge sweep of Λ=50°. The results showed that, at lower Reynolds number, a pair of steady leading edge vortex develops over the wing at 5° angle of attack, and the primary vortex breakdown happens at smaller angle of attack. Moreover, in certain range of angle of attack, another pair of concentrated vortex forms outside the primary leading edge vortex, they together compose of dual vortex structure, which has been observed both in the experimental and computational studies. As the angle of attack increased, the core of the primary vortex gradually goes away from the wing upper surface, and the primary reattachment lines move towards the center-line of the model. Therefore, the region between the secondary separation line and the secondary attachment line is expanded.