Aerodynamic and angular motion characteristics of a fixed-canard dual-spin projectile under different forebody spinning rates

In this paper, a numerical study is conducted on a fixed-canard dual-spin projectile to explore its aerodynamic and angular motion characteristics at different forebody spinning rates. Based on the Reynolds-averaged Navier–Stokes equations, unsteady simulations of the dual-spin projectile rotating around its longitudinal axis are performed to investigate its aerodynamic characteristics. The results indicate that the spinning of the forebody induces a discrepancy in the effective angle of attack between the left and right canards. This discrepancy, in turn, gives rise to an asymmetric wingtip vortex structure, which ultimately exerts significant influence on the aerodynamic characteristics of the dual-spin projectile. Furthermore, based on the coupled computational fluid dynamics and rigid body dynamics approach, the aerodynamic and angular motion characteristics of the dual-spin projectile during flight are investigated, and the mechanism of the angular motion is analyzed. The results demonstrate that the forebody spinning significantly affects both the aerodynamic characteristics and angular motion characteristics of the projectile. Among the underlying mechanisms, the projection of the resultant moment onto the projectile axis is identified as the dominant contributing factor. A non-positive projection induces convergence of the complex angle of attack, thereby enhancing stability of the spinning projectile. Based on these findings, a control strategy is proposed: to improve angular motion stability, the forebody is either driven to spin in the opposite direction or remained in a stationary state.