The Charge Designer?s Workbench: A Range of Interior Ballistic Modeling Tools

Abstract : Gun and ammunition designers typically employ various models initially to evaluate preliminary design concepts and ultimately to make specific decisions regarding the design and optimization of both individual components and all-up weapon systems. A wide range of computerized models exists today to address virtually every aspect of this process; in particular, the propelling charge designer has available several levels of interior ballistic models. These range from rather simple lumped-parameter models, providing basic performance data such as muzzle velocity and peak pressure and which run quickly on personal computers, to very complex multidimensional, multiphase flow models capable of describing the details of flamespreading, grain motion, and the formation of pressure waves, but employ specialized and occasionally unavailable input for propellant, charge, and gun parameters and require many hours on a workstation or supercomputer to complete the simulation. This report addresses the increasing level of physics and thus range of applicability to problems of increasing sophistication associated with three of today's most popular interior ballistic models: the lumped-parameter IBHVG2 code, the one-dimensional, two-phase flow XKTC code, and the state-of-the-art multidimensional, multiphase flow NGEN3 code. Recommendations are made with respect to the appropriate use of each of these highly useful tools, as well as the transferability of input data and comparability of results so obtained.