Photogrammetry of the Particle Trajectories on Dipole West Shots 8, 9, 10,and 11. Volume IV. Shot 11.

摘要

This volume describes the photogrammetry and analysis of the particle trajectories in blast waves produced by the simultaneous detonation of two spherical 1080-lb (490-kg) Pentolite charges (DIPOLE WEST Shot 11). One of the charges was positioned at a height of 25 feet above smooth ground, and the second charge 50 feet above the first. Photogrammetrical measurements were made of the trajectories of air particle flow tracers (smoke puffs) which had been placed in a vertical grid at heights ranging from 3 to 58 feet above the ground and at radial distances ranging from 25 to 140 feet from the vertical axis through the charges. From the measured particle trajectories, calculations were made of the particle velocities, densities, hydrostatic overpressures, dynamic pressures, and total pressures throughout the blast wave, at times ranging from 3 ms to 110 ms after detonation of the charges. The shock front times-of-arrival were also determined for the primary shock from each of two charges, for the Mach stems produced above and below the interaction plane midway between the two charges, and for the Mach stem produced at the ground surface. From the shock front times-of-arrival, calculations were made of the shock velocities and, in turn, the peak particle velocities, air densities and hydrostatic overpressure immediately behind each shock.