FCT simulation of HOB airblast phenomena. Memorandum report

Technical Report · Tue Sep 29 04:00:00 EDT 1981

OSTI ID:5338735

Kuhl, A L; Fry, M A; Picone, M; Book, D L; Boris, J P

Height-of-burst (HOB) detonations can create airblast environments which are more severe than surface burst environments at high overpressures (>100 psi). A double Mach stem structure develops during shock reflection from the ground at a range approximately equal to the HOB. This creates double peak static pressure waveforms with enhanced early-time impulses. Blast diffraction on above ground structures also contains multiple peaks with enhanced loads and impulses. There is an ongoing interest in simulating these HOB environments for military applications. High explosives (HE) charges can be used to simulate the nuclear surface burst case below about 100 psi for reasonable yields (100T or more), but it appears that it is impractical to elevate large HE charges above grade to simulate the HOB case. In this paper we propose a new method for naturally simulating such HOB environments on a large scale. A hemispherical HE charge could be detonated near a natural slope which had been graded to form a large ramp. When the spherical blast wave reflects from this ramp a shock structure and environment is created which is similar to the HOB case. Validity of this concept is demonstrated by numerical simulations with a nonsteady 2-D FCT hydrocode. These calculations indicate that a 30 degree ramp located 200 ft from a 500T hemispherical HE charge will create 400 to 600 psi double peak static pressure waveforms at distances of 40 to 60 ft up the ramp; time between peaks is 1 ms. These waveforms correspond to a nuclear detonation at 100 to 120 ft/KT to the 1/3 power power and a ground range of 190 to 210 ft/KT to the 1/3 power.

• Research Organization: Naval Research Lab., Washington, DC (USA)
• OSTI ID: 5338735
• Report Number(s): AD-A-107920/1; NRL-MR-4613
• Country of Publication: United States
• Language: English

Related Subjects

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE
450200* -- Military Technology
Weaponry
& National Defense-- Nuclear Explosions & Explosives
ALTITUDE
ATMOSPHERIC EXPLOSIONS
CHEMICAL EXPLOSIVES
COMPUTERIZED SIMULATION
DIMENSIONS
EXPLOSIONS
EXPLOSIVES
HEIGHT
MACH NUMBER
NUCLEAR EXPLOSIONS
REFLECTION
SHOCK WAVES
SIMULATION
SURFACE EXPLOSIONS
VELOCITY
WAVE FORMS