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Three-Dimensional Numerical Fluid Flow Simulation of the Interior and Transitional Ballistics Process

We report on the realization of a numerical tool to simulate the three-dimensional fluid flow associated with the interior ballistics problem of propellant based weapon systems. The model is based on a two-phase approach, in which the gaseous and the solid phase, representing the propellant bed, are assumed to be a homogeneously stirred mixture. The ignition and the combustion of the propellant grains are taken into account via heat and mass transfer, respectively, between the two phases. To numerically solve the governing set of equations, a Godunov scheme based on an approximate Riemann solver is applied. Interior ballistics simulations on a 60 mm weapon and experimental findings are compared and it is shown that the presented model, in principle, is also able to predict the muzzle flash after the projectile left the barrel