A 2-D Axisymmetric Model of a Stretching Jet in ALEGRA

Abstract : This report presents a numerical model of a stretching copper jet, representative of a Viper shaped charge jet at 35 microsecs following detonation. A liner collapse and jet formation model is used to extract data for the jet geometry and the axial velocity distribution. Numerical simulations are carried out using ALEGRA (Arbitrary Lagrangian Eulerian General Research Application), and the results are compared to previously published experimental data and numerical results. ALEGRA results at 35 microsecs are then corrected to more accurately reflect experimental observations in the new model representing the stretching jet at the point of impact. Sensitivity studies are conducted using the stretching jet model to determine the effects of computational mesh at later times.