Influence of Reynolds Number on Vortex Flow over a Nonslender Delta Wing

Through computational simulations performed for a 50 degrees sweep delta wing at low Reynolds numbers Re = 8.7 x 10(3) - 4.0 x 10(4), this paper presents the features of the flow structures over the delta wing including the separated vortical flow, the onset of vortex breakdown, surface flow features, and dual vortex phenomena. At the lowest Reynolds number Re = 8.7 x 10(3), no dual vortex structures are observed. As the Reynolds number is increased the dual vortex structures are developed, and the spanwise location of the vortex core is moved toward outboard without obvious variation of the vortex core vertical location above the wing leeward surface. At the lower Reynolds numbers investigated, the vortex breakdown location moves upstream as the Reynolds number increases. The primary reattachment lines move outboard toward the leading edge with the increasing Reynolds number, and simultaneously the start point of the secondary separation moves forward toward the tip of delta wing.