Quantitative Evidence of Reaction during Hypervelocity Penetration of Aluminum through Oxygenated Fluids

Qualitative evidence of chemical reactions between combustible metal shaped charges in air and water has previously been reported based on high-speed photography, spectroscopy, and calorimetry. This report covers investigations directed towards quantifying the conditions under which reaction occurs and the consequences on terminal encounter with submerged inert steel plates. In order to distinguish effects hypervelocity long-rod and shaped charge jet impact experiments were conducted in inert fluid, water and concentrated hydrogen peroxide. It is shown that reaction causes foreshortening of aluminum penetrators at rates that are more competitive at impact velocities towards the slow end of an effective penetrating jet, and that localized reaction and thermal expansion of ablative particulates prior to and after impact can cause substantial plate deformation. The results are consistent with hydrodynamic penetration theory when modified for reaction induced foreshortening. Predicted impact and penetration effects against submerged steel plates submerged in a chemically inert fluid are shown to agree with experiment, and the effect of density difference between the selected spindle oil inert simulant, water and concentrated hydrogen peroxide are shown to be within experimental variation.