Multi-fidelity Simulation Tool for Hypervelocity Aerodynamic Interaction of Ballistic Bodies

Many military systems dispense objects such as submunitions or fragments which are designed to destroy targets through explosive munitions or hypervelocity impacts. The dispersion pattern of the dispensed objects is of paramount importance in determining the efficacy of the system as a weapon. The routine modeling of such systems is prohibitive through traditional computational methods, such as CFD. An approach to modeling dispense events is required that is fast, approximate, but accounts for highly chaotic and indeterminate physical processes such as collisions, time-dependent aerodynamic interference, and the interaction of the objects with the parent vehicle. Kord Technologies proposes an innovative approach to the fast simulation of multiple-body dispense based on Autoregressive-Moving-Average (ARMA) modeling. In this approach, forces and moments on an object are expressed in terms of approximate values based on simplified CFD analyses, and stochastic terms based on the analysis of Navier-Stokes/6DOF computations that have been run previously on a dispense vehicle. The stochastic terms account for the more complicated aspects of object dispersion, such as collisions between objects. Once the ARMA model coefficients are established, the model can be run in a Monte Carlo mode to determine the most likely dispersion patterns BENEFIT: The technology developed during this effort will have broad applicability to any DOD system which relies on successful dispense of many bodies such as Brilliant Anti-Tank System, MODS darts, etc. It is also anticipated that this technology will be useful in other areas such as swarming systems, etc