Numerical Analysis of Small Caliber Spinning Projectile with Variety Boattail Configurations

Range extension has received great interest in the field of artillery and spinning projectiles. Reducing base drag is an effective way for rang extension, because it is a major component in transonic and supersonic Mach numbers. Boattailing is considered as one of the most implemented techniques to reduce base drag. This work uses variety of passive drag reduction techniques over M33.50cal projectile. Multiple design variations on projectile boattail are considered. This includes varying boattail angle, use of riblets, and use of arced boattail. Computations are conducted using computational fluid dynamics by solving RANS equations. Simulations are performed over Mach numbers from 0.6 to 2.5. The aim of the simulations is to calculate most affecting aerodynamic forces and moments which include drag force, lift force, Magnus force, Magnus moment, overturning moment, and spin damping moment. Then these coefficients are compared for all design variations. Results are validated by comparing with experimental and numerical results from the literature. Furthermore, a mesh independence study is done for verification. It was found that every configuration has good performance at a certain speed range with regard to zero yaw drag and significant yaw drag reduction for riblets boattail for low supersonic speeds.