Aerodynamic and Stability Analyses of Osculating Cone Waveriders with Variable Tip Shapes

Waveriders represent unique aerodynamic configurations with the ability to achieve excellent aerodynamic efficiency for high-speed cruising vehicles. The osculating cone waverider methodology provides significant flexibility in generating waverider shapes, but conventionally flat and anhedral waveriders have been studied, and there is a limited number of studies on dihedral waveriders. Further, a new design limit criterion is used to evaluate the non-dimensional tip height, which is higher than conventional designs. Three distinct osculating cone waveriders are generated with non-dimensional tip heights, characterized by anhedral (0.3), dihedral (1.7), and flat (1) configurations. Examination of the geometric characteristics indicates that the dihedral configuration demonstrates the highest volumetric efficiency, surpassing its anhedral counterpart by 15$\%$. Simulations are performed under both on-design and off-design conditions. Specifically, under on-design conditions, the anhedral waverider exhibits superior aerodynamic performance compared to the other two configurations, boasting an L/D ratio that is 18$\%$ higher than its dihedral counterpart. In off-design situations, both the dihedral and flat waveriders demonstrated stability in lateral and directional directions. The dihedral waverider exhibited higher rolling moment and yawing moment derivatives, indicating its superior lateral and directional stability compared to the flat waverider. However, the anhedral waverider, although directionally stable, showed lateral instability characterized by positive yawing and rolling moment derivatives. Additionally, all three waveriders were observed to be longitudinally unstable, displaying comparable pitching moment derivatives. The study also shows that a local surface inclination-based theory is able to explain aspects of the pressure distribution which affect the forces and moments over the body.