The aerodynamic parameters and flight characteristics of projectiles with different grooves for UAV countermeasure: A comparative study

Unauthorized flights of unmanned aerial vehicles (UAVs) pose significant threats to both aircraft operational safety and public security. Launching projectiles via compressed gas devices has emerged as an effective hard-kill approach for UAV countermeasures, the efficiency and accuracy of which critically depend on high-precision flight prediction. This paper proposes a methodology for modeling the aerodynamic parameters of grooved projectiles. Specifically, six-degree-of-freedom equations are derived within a zero-wind reference frame, and a multi-wind separate calculation scheme is developed. Based on this framework, a high-precision flight prediction workflow is established. Aerodynamic modeling and flight trajectory simulations are conducted for three projectile configurations: un-grooved, rectangular-grooved, and polygonal-grooved. The results demonstrate that grooved projectiles improve axial flow characteristics in the boat-tail region and suppress the development of vortical structures in the radial cross section, thereby offering advantages in reducing flow losses and drag. These findings underscore the efficacy of groove-based flow control, with the polygonal-grooved configuration outperforming its rectangular-grooved counterpart. Notably, the aerodynamic parameters and flight characteristics of both grooved projectile types differ substantially from those of the un-grooved projectile, indicating that surface grooves exert a considerable influence on aerodynamic behavior—a factor that must be duly accounted for in aerodynamic modeling. Among the grooved variants, the polygonal-grooved projectile exhibits superior performance, characterized by a lower drag coefficient, extended supersonic flight range, enhanced wind resistance, and reduced dispersion.