Accession Number : ADA181123

Title :   The Interaction Phenomena between Adjacent Detonating Layers.

Descriptive Note : Final rept. 1 Jul 83-14 Jan 87,

Corporate Author : MICHIGAN UNIV ANN ARBOR GAS DYNAMICS LABS

Personal Author(s) : Nicholls,J. A. ; Sichel,M. ; Kauffman,C. W.

Report Date : 06 MAY 1987

Pagination or Media Count : 13

Abstract : Two adjacent 1.6 cm square detonation tubes, separated at the test section by a 50 nm thick cellulose film, were used to observe the interaction which occurs when a normal detonation in the primary gas comes into contact with a bounding explosive mixture. A pulsed argon ion laser and a high speed camera system were used to obtain Schlieren framing photographs of the interacting waves at 2 microsec intervals with an intervals with an exposure time of 12 ns. Experiments were made using stoichiometric H2-02 mixture as the primary explosive, and using H2-O2 mixtures with equivalence ratios ranging from 0.15 to 4.5 for the secondary bounding explosive. At the first instant of contact a bubble or blast wave was observed to propagate into the secondary explosive, and in some cases a micro explosion in this bubble led to almost instant transition to oblique detonation. Otherwise an oblique shock is induced in the bounding explosive which is reflected from the shock tube wall. Shock polar analysis was used to compute the details of the interaction at the interface between the primary and secondary explosives. A simplified method for rapid computation of oblique detonation polars was developed for this purpose, and used to compute the conditions behind the induced oblique detonations and shock waves. There was good agreement between computed and measured shock angles; but computed oblique detonation angles, while showing the proper variation with the equivalence ratio, were always lower than the observed values.

Descriptors :   *DETONATIONS, *INTERACTIONS, *INTERFACES, *BLAST WAVES, *GAS DYNAMICS, LAYERS, ANGLES, EXPLOSIVES, MIXTURES, EXPLOSIONS, RATIOS, HIGH SPEED CAMERAS, TRANSITIONS, SCHLIEREN PHOTOGRAPHY, SECONDARY, COMPUTATIONS, POLAR REGIONS, SHOCK WAVES, TEST EQUIPMENT, SHOCK, ARGON LASERS, IONS, PULSED LASERS, BOUNDARIES, SIMPLIFICATION, CELLULOSE, THICK FILMS

Subject Categories : Explosions

Distribution Statement : APPROVED FOR PUBLIC RELEASE