Multiple-Body Collision Algorithms for Computational Simulation of High-Speed Air-Delivered Systems

Harris, R., Liever, P., Luke, E., & Dudley, J. (2015). Multiple-Body Collision Algorithms for Computational Simulation of High-Speed Air-Delivered Systems. Communications in Computatational Physics. Global Science Press. 17, 564-593.

Abstract

Abstract. Currently, there exists a lack of confidence in the computational simulation of multiple body high-speed air delivered systems. Of particular interest is the ability to accurately predict the dispersion pattern of these systems under various deploy- ment configurations. Classical engineering-level methods may not be able to predict these patterns with adequate confidence due primarily to accuracy errors attributable to reduced order modeling. In the current work, a new collision modeling capabil- ity has been developed to enable multiple-body proximate-flight simulation in the Loci/CHEM framework. This approach maintains high-fidelity aerodynamics and in- corporates six degrees of freedom modeling with collision response, and is well-suited for simulation of a large number of projectiles. The proposed simulation system is intended to capture the strong interaction phase early in the projectile deployment, with subsequent transfer of projectile positions and flight states to the more economi- cal engineering-level methods. Collisions between rigid bodies are modeled using an impulse-based approach with either an iterative propagation method or a simultane- ous method. The latter is shown to be more accurate and robust for cases involving multiple simultaneous collisions as it eliminates the need to sort and resolve the col- lisions sequentially. The implementation of both the collision detection methodology and impact mechanics are described in detail with validation studies to demonstrate the efficiency and accuracy of the developed technologies. The studies chronologi- cally detail the findings for simulating simple impacts and collisions between multiple bodies with aerodynamic interference effects.