Progress in the Development of a Multiphase Turbulent Model of the Gas/Particle Flow in a Small-Caliber Ammunition Primer

摘要

There is significant experimental evidence that burning particles of various chemical compositions and sizes are ejected from gun primers and that these particles interact with the propellant grains during main charge ignition. This explicit ignition phenomenon is thought to be incompatible with the implicit treatment of primer function in conventional interior ballistics codes and models. Generally, the primer efflux is treated as a hot gas that evolves from a specified region in the model's representation of the gun chamber (usually along the chamber centerline and near the breech). What amounts to an igniter table is arrived at by experimental means and by careful calibration of the interior ballistics simulation using gun firing data. With the advent of multidimensional, multiphase interior ballistics codes which employ coupled Eulerian-Lagrangian schemes to explicitly treat both the gas and solid phase, the time is ripe for a primer model that is commensurate with the availability of such an interior ballistics model. Progress in the development of a primer model that is compatible with the ARL-NGEN3 interior ballistics code and small-caliber weapons is described herein. The model is based on the One Dimensional Turbulence modeling approach that has recently emerged as a powerful tool in multiphase simulations. Initial results are shown for the model run as a stand-alone code and are compared to recent experiments with small-caliber primers.