CFD Analysis of Small Caliber Spinning Projectile with Variety Base Configurations

Abstract

Range extension got a great interest in the field of artillery and spinning projectiles. Reducing base drag is an effective way for rang extension, since it is a major component in transonic and supersonic Mach numbers. Base modification is considered as one of the implemented passive techniques to reduce base drag. This work utilizes variety of base cavities over M33 .50 cal projectile. Two size variations on projectile base are considered. This includes 2 mm and 4 mm depth. Computations are conducted using computational fluid dynamics CFD using Ansys Fluent to solve 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. Generally, base cavity has minor effect on most of aerodynamics coefficients. Though, large base cavity has low zero-yaw drag and yaw drag relative to the reference projectile.