Hypervelocity impact and aerodynamic breakup of liquids

Abstract

In a recent series of hypervelocity (HV) impact tests at Arnold Engineering Development Center (AEDC) using light-gas gun technology, tests were performed in which 4-petal sabot containers filled with liquid polymer were fired into rarefied atmospheres. Events were studied by a variety of techniques, including fast framing optical cameras, flash X-Ray and laser shadowgraphy, drop stain image analysis measurements. Sabots were allowed to depetal, i.e. strip off aerodynamically. Surfaces of the liquid polymer so exposed were examined for two-fluid wind driven instabilities and breakup. This paper reports on a novel viscosity dependent instability growth model which focuses on the physics of high wind shear fluid breakup. Comparison of the model and test data provides new perspectives on: • ⊎ HV wind driven growth instabilities in Newtonian liquids • ⊎ Impacting non-Newtonian pseudoplastic or viscoelastic fluids • ⊎ HV interpenetration of solids undergoing mutual plastic flow