Micro-jetting: Areal density calculation from a triangular groove

Abstract

We present a method for calculating the mass ejected during the reflection of a shock wave on a triangular groove. This calculation is based on the combination of two models taken from the literature, BMPT-2, on the one hand, for the calculation of the velocity and density of the jet, and fragmentation zone propagation (FZP ) on the other hand, for the calculation of the ejected mass, certain parameters required for FZP being determined by BMPT-2. Compared with previous work, FZP has been extended to deal with the various stages of jet formation. The approach was first evaluated on tin using a large-scale molecular dynamics simulation. This first step validated the overall phenomenology and the associated theoretical tools, and enabled us to propose a procedure for adjusting FZP. Next, we used the BMPT-2/FZP combination to analyze ejected mass measurement experiments using Asay foil. The areal mass curves are well reproduced with few parameters, showing that there is no inconsistency between BMPT-2/FZP and the experiments. Finally, a more detailed analysis of the results obtained enables us to set the limits of the jet thickness at the moment of rupture, and to propose a simple analytical form of its profile compatible with the model used.