Effect of a centerbody on the vortex flow of a double-delta wing with leading edge extension

The effect of the presence of a centerbody on the vortex flow of a uniquely-shaped double-delta wing was experimentally investigated through simultaneous off-surface flow visualization and wing-surface pressure measurements. The uniquely-shape double-delta wing was formed by attaching a leading edge extension (LEX) to the apex portion of a 65-deg sweep delta wing with sharp edges. The flow Reynolds number was 1.82×1051.82×105 for the off-surface flow visualization, 1.76×1061.76×106 for the wing-surface pressure measurement. Visualization results show that the presence of a centerbody under the lower surface of the double-delta wing model slightly advanced coiling interaction of the wing and LEX vortices at the downstream chord positions, at least for the selected angle of attack of 24-deg. Quantitative analysis of wing-surface pressure measurements revealed the effects of the presence of a centerbody to be prominent for the cases with higher angles of attack and sideslip angles. Up to angle of attack α=24-degα=24-deg, the presence of the centerbody had a small influence on the suction pressure distribution on the wing upper surface, even at the large sideslip angle of −20-deg. However, at higher angles of attack of 28-deg and 32-deg, the presence of the centerbody caused a decrease in the magnitude of suction pressure distributions on the wing's upper surface, and the difference of the suction pressure distribution between the two configurations was not negligible at non-zero sideslip angles.