Reynolds Number and Leading Edge Bluntness Effects on 65° Delta Wing at Subsonic Speed

The vortex properties over a delta wing depend mainly on angle of attack (α), Mach number (M), Reynolds number (Re) and leading edge (LE) bluntness. In the case of delta wing with blunt LE, separation of the primary vortex is from the tip of the wing .To study the effect of LE bluntness and Reynolds number experiments were carried out on delta wings with 65° sweep. Four models with different wing leading edge (LE) radii were tested in wind tunnel. The experiments were carried out in the Mach number range of 0.3 to 1.2 in the 1.2m Trisonic wind tunnel at NAL. Angle of attack was varied from -5° to 26°. The forces and moments were measured using six components balance. Studies were also conducted to obtain Surface flow visualization using oil flow technique. Surface flow visualization data has been used to correlate force measurement data. Results show that flow at higher Reynolds number exhibits higher lift. The higher Reynolds number flow displays severe pitch up compared to low Reynolds number flow. Lift and pitching moment characteristics are strong function of Leading edge bluntness. With increase in LE bluntness overall lift decreases