Measurement of Pressure and Related Energy Output from Thermally Ignited Pyrotechnic Compositions Burning in a Partially Vented Vessel
Abstract
In an effort to determine the hazards of preparing pyrotechnic compositions in processing bays, a study was conducted in which a series of compositions were thermally ignited in a vented vessel and the resulting pressure versus time, rate of pressure rise, and velocity of the air pressure wave were measured. The compositions were a standard illuminating material, a photoflash powder, an igniter, a delay powder, and a formulation which generates IR radiation. These experiments showed that the pressure increased linearly with (a) increasing loading density for a constant vent, and (b) decreasing vent size for constant loading density. For the linear part of the pressure-time trace, rate of pressure rise also increased with increasing loading density and with decreasing vent size. This latter result shows the effect of pressure on burning rate. Velocities of the air pressure wave were obtained in excess of the speed of sound, indicating a low velocity detonation had taken place. Very low TNT equivalences for pressure were obtained, the largest being only 0.61; those for impulse were 0.6 through 0.9 with the smallest vent for the compositions (except the gasless delay powder which was only 0.05), reflecting the relatively long duration of positive pressure produced by these compositions.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1981
- Accession Number
- ADA100728
Entities
People
- Francis R. Taylor
- Leroy Hunter
- Patricia L. Farnell
Organizations
- United States Army Armament Research, Development and Engineering Center