Accession Number : AD0654175

Title :   MECHANISMS IN THE GENERATION OF AIRBLASTS BY UNDERWATER EXPLOSIONS,

Corporate Author : BOLT BERANEK AND NEWMAN INC CAMBRIDGE MASS

Personal Author(s) : Malme,Charles I. ; Carbonell,Jaime R. ; Dyer,Ira

Report Date : 23 SEP 1966

Pagination or Media Count : 162

Abstract : Research studies and small-scale experimental tests were conducted to explore the formation and propagation of airblasts resulting from underwater explosions. 'Deep' explosions produce an interface velocity above the charge that is subsonic in air. The resulting airblast signature was found to be produced by acoustic radiation from a large surface area following the passage of the transmitted shock. In general, the interface velocity could not be predicted by linear continuous theory because of cavitation and subsequent separation of the surface layers near the charge. When the interface velocity above the charge is supersonic, the character of the airblast signature becomes more shocklike and the explosion is said to be 'shallow.' While the airblast generating mechanisms of deep explosions are still present, their effect is generally overshadowed by the shock wave associated with the supersonically rising dome and plume. The intensity of this shock is closely related to the Mach number of the plume. This permits an approximate calculation of the peak airblast pressure using existing theory of off-axis shock-wave generation by supersonic blunt bodies. (Author)

Descriptors :   (*BLAST, *UNDERWATER EXPLOSIONS), PROPAGATION, EXPERIMENTAL DATA, INTERFACES, EXPLOSION EFFECTS, SHOCK WAVES, MODEL TESTS

Subject Categories : Explosions

Distribution Statement : APPROVED FOR PUBLIC RELEASE