Photogrammetry of the Particle Trajectories on Dipole West Shots 8, 9, 10, and 11. Volume V. Comparison of Results

摘要

Volume V, the final volume of this series, compares the results obtained by photogrammetry of smoke-puff particle flow tracers in four experiments (DIPOLE WEST Shots 8 to 11) involving the simultaneous detonation of pairs of 1080-lb (490-kg) Pentolite charges. In Shots 8 and 11, one charge was at a height of 25 feet (7.6m) above the ground, and the second charge was 50 feet (15.2m) above the first. The corresponding distances for Shots 9 and 10 were 15 feet (4.6m) and 30 feet (9.2m). For Shots 8 and 9, the ground surface was smooth, and for Shots 10 and 11, the ground close to the charges was roughened by ploughing to a depth of approximately 14 inches (35 cm). The analysis of the photographically observed particle trajectories in the blast waves of each experiment provided information on the strengths of the primary and Mach stem shock waves, and a measure of the space and time variations of particle velocity, density, hydrostatic overpressure and dynamic pressure in the blast waves. Comparisons between these results from the four experiments show complete consistency in the trajectories of the primary shocks from all eight charges, indicating that they all detonated satisfactorily with equal energy yields. The measurements of the Mach stem blast waves above and below the horizontal interaction planes between the pairs of charges provide a set of 'ideal' values against which to compare blast wave reflections from real ground surfaces.