Investigation of surface pressure and leading-edge vortex of slender delta wings

Abstract An overview is given of investigations on a 70° slender delta wing applying pressure-sensitive paint (PSP) and particle image velocimetry (PIV) in parallel. Experiments are conducted within the range of Reynolds number from 0.6 $$\times$$ × 106 to 1.2 $$\times$$ × 106 and angle of attack from 15° to 30°. The focus is on systematically studying the correlation between leading-edge vortex (LEV) and surface pressure distribution under different conditions. It is found that the suction peak does not exactly coincide with the vortex center. The shift of the suction peak is more pronounced at higher angles of attack or Reynolds numbers, reflecting the effect of the asymmetry of the corresponding velocity gradient distribution on the pressure distribution. Additionally, under certain conditions, the reduction of streamwise variation may weaken the three-dimensionality of the LEVs, which has a significant impact on their pressure distribution.