Computational Simulation of High-Speed Projectiles in Air, Water, and Sand

Abstract

Abstract : The development of a comprehensive computational fluid dynamics approach for conducting simulations of projectile penetration into water-saturated sand is reported. High resolution upwind schemes suitable for a fluid dynamic system consisting of gas, liquid, and dispersed solids phases are derived and are combined with a time-derivative preconditioning strategy for efficient time integration at all flow speeds. A solids-stress model based on Mohr-Coulomb critical-state theory is used to account for compaction and deformation of sand during projectile penetration. An overset-mesh framework is also implemented in order to handle projectile relative motion in subsequent work, and improved phase interface capturing methods are also developed and tested. Results are presented for two sets of experimental data involving projectile penetration into dry sand. The computational results are sensitive to the solids-stress model and the drag coefficient predictions are generally lower than indicated in the experimental data.