SHOCK CHARACTERISTICS OF SMALL PENTOLITE CHARGES DETONATED IN VESSELS HYDROSTATICALLY PRESSURED FROM AMBIENT TO 4000 PSI
Abstract
Underwater explosions at great depth have been simulated by detonating small spherical pentolite charges in vessels hydrostatically pressured to 4000 psi. An increase in hydrostatic pressure is found to have no effect on the peak magnitude of the primary shock wave, but the impulse per unit area and the duration of the positive phase of the initial pressure pulse are observed to decrease with an increase in hydrostatic pressure. The magnitude of the negative phase of the shock wave increases as the hydrostatic pressure increases. Although little difficulty is encountered in studying primary pressure pulses in pressure vessels, secondary pressure pulses created by expansion and contraction of the gas bubble formed by the detonation are difficult to observe due to the large displacement of the water particles at close-in distances and the associated acceleration of the piezoelectric pressure transducer at the times of interest. Also, the myriad of reflections from the gauge positioning devices and the vessel walls and the inconsistency usually exhibited by bubble pulses under seemingly identical conditions complicate analysis of the secondary pulses. The magnitude of the bubble pulse appears to increase as the hydrostatic pressure increases, and, at moderately high hydrostatic levels, the frequency of the bubble oscillation is such that the bubble pulse is recorded as a vibration.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 07, 1965
- Accession Number
- AD0474020
Entities
People
- B. W. Vanzant
- R. C. Dehart
Organizations
- Southwest Research Institute