Advanced Discrimination Technologies and Concepts

A new hybrid model will be developed under this Phase II effort predicting the propagation of transient bursts at high-altitudes that can be used to design and evaluate flux-based discrimination concepts. The hybrid model has 3D continuum (CRAFT CFD® Code), DSMC (DAC97 Code), and free molecular components and performs the complete analysis from burst source to farfield, interfacing solutions along a Bird continuum breakdown surface and the free molecular onset boundary. In the Phase I effort, the approach was demonstrated for high-altitude spherical bursts in both a quiescent environment and high-speed stream which slows down the burst and deforms it. Novel grid adaptation techniques are employed to ensure accuracy at wave fronts. Threat vehicle or lighter objects flying through the moving, transient burst are analyzed using 6DOF methodology combined with “snapshot” DSMC simulations performed at numerous points along the trajectory, permitting a high-accuracy analysis of changes in velocity and trajectory as required for discrimination. Validation of this hybrid model will be performed using new data sets being obtained in the CUBRC altitude chamber and shock tunnel facilities. A scope-out task to evaluate particle-based discrimination concepts will also be performed using the new particle capabilities available in the hybrid model.