A study of unsteady projectile aerodynamics using a moving coordinate method

Abstract

A computational fluid dynamics (CFD) method has been applied to simulate unsteady near-field aerodynamics of the projectile which is launched from a ballistic range. A moving coordinate scheme for a multi-domain technique was employed to investigate the unsteady flow with moving boundary. The coordinate system fixed to each moving domain was applied to the multi-domains, and the effect of virtual mass was added in the governing equations for each domain. The unsteady, axi-symmetric Euler equation systems were numerically solved using the third-order Chakravarthy-Osher total variation diminishing scheme, with Monotone Upstream-centered Scheme for Conservation Laws (MUSCL) approach. The present computations were validated with results of some other CFD works and experimental data available. The computed results reasonably capture the major flow features, such as shock waves, blast waves, shear layers, vortical flows, etc which are generated in launching a projectile up to a supersonic speed. The projectile mass, configuration, and the initial conditions behind the projectile have been varied to investigate its effect on the flow field and the unsteady projectile aerodynamics. The unsteady aerodynamics of the projectile is strongly affected by the projectile mass and configuration. The initial conditions behind the projectile have strong influence on the near flow field structures which govern the development of the blast wave along with the projectile motion.