Aerodynamic and dynamic analyses of three common4.5 mm-caliber pellets in a transonic

Abstract. In this paper, a numerical solution of the Navier-Stokes equations is considered using the Jameson method in the transonic ow regime over three air gun pellets. The considered pellets have the same caliber of 4.5 mm, but dierent nose shapes; they are axisymmetric projectiles of three basic types, namely wadcutter, sharp pointed, and roundnose. After these pellets have been modeled geometrically, the Navier-Stokes equations as the governing equations of the ow eld around the pellets are solved. Computed aerodynamic results have been used in order to analyze the trajectories of the projectiles, dynamically. The variation of the drag coecient by Mach number of the free stream ow, which is a key point for the dynamic analysis of the projectile motion, has been obtained. The dynamic analysis of the motion of pellets precisely describes the trajectory and how the velocity of the pellet and the altitude slump with time and location. Relying on these analyses, from both aerodynamic and dynamic points of view, the round-nose pellet in a variable range of Mach numbers shows the best aerodynamic and dynamic behaviors in comparison with other pellets.