Measurements of Normally Reflected Shock Parameters from Explosive Charges under Simulated High Altitude Conditions
Abstract
Normally reflected shock parameters including peak excess pressure, first positive impulse, positive duration and arrival time at scaled distances between 1 and 7 feet per pound to the 1/3 power and ambient pressures of 0.3 to 0.1, 0.01, and 0.0007 atmospheres are presented. Sachs' scaling theory was applied to these parameters. It was found that Sachs' scaling is valid for predicting the magnitude of the first shock appearing in the pressure-time history. As the ambient pressure is reduced the magnitude of this first shock decreases; however, at ambient pressures in the vicinity of 0.01 atmosphere the initial shock is followed by a relatively slow-rising pressure pulse, the peak of which exceeds the peak of the first shock. The peak pressure of this secondary pulse is not predictable by Sachs' scaling. It is indicated that at very low ambient pressures the initial shock will disappear entirely. Spherical charges of Pentolite (50/50, TNT/PETN) with a nominal weight of 1/8 pound were used for these experiments.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1965
- Accession Number
- AD0469014
Entities
People
- B. F. Armendt Jr.
- W. H. Jack Jr.
Organizations
- Ballistic Research Laboratory