Stereoscopic Retroreflective Shadowgraph System for Warhead Characterization

Spectral Energies, LLC in collaboration with New Mexico Tech proposes to develop a novel stereoscopic retroreflective shadowgraph system for measuring fragment propagation velocities and sizes throughout a large field of view for application to warhead arena or sled testing. Our approach is to use high-speed stereo shadowgraph imaging to identify individual fragments and associated compressible flow phenomena throughout the blast field. The shadowgraph imaging will identify individual fragments and the compressible phenomena (oblique shock waves, compressible-turbulent wakes) associated with the fragment motion. It allows an independent measurement of fragment velocities through the visualization of the oblique shock wave angle, which gives propagation Mach number, and the velocity vector via visualization of the turbulent wake behind the particle. The stereo imaging allows measurement of the three-dimensional position of each fragment, and when combined with high-speed cameras and the shadowgraph technique, it allows velocity measurement. Fragment shape and size will be estimated from the high-speed stereo images.