Reaction rates from pressure-gauge measurements in reacting explosives
The proper hydrodynamic data and an equation of state are sufficient to describe quantitatively the reaction rates of explosives during the shock-to-detonation transition. Manganin pressure gauges embedded in the reacting explosive have provided these data for the explosives PETN, PBX 9404, TATB, and TNT. Once a pressure-field history has been assembled from individual pressure histories at different depths in the explosive, the conservation equations can be applied in a Lagrangian analysis of the data. The combination of a reactant-product equation of state with this analysis then allows the calculation of the extent of reaction and reaction rate. Successful correlation of the calculated reaction rate values with other thermodynamic variables, such as pressure or temperature, allows formulation of a rate law and the prediction of initiation behavior under circumstances quite different from the experiments that led to the rate law. The best dynamic piezoresistive pressure gauge for most applications would have a substantial output voltage and present negligible disturbance to the flow. In explosives, however, requirements for survival in the extreme temperature and pressure environment encountered by the gauge dictate compromise. Low electrical resistance (approx. 20 m..cap omega..) helps to minimize shunt conductivity failures, but this drastically reduces output and demands that much attention be given to reducingnoise. Although relatively thick insulation perturbs the flow to some extent, survivability requirements dictate its use. Pressure measurements in reactive flow can now be made routinely with gauges that successfully produce data leading to a description of the flow and a powerful predictive capability.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 6254119
- Report Number(s):
- LA-UR-81-2482; CONF-810931-3; ON: DE81030252; TRN: 81-016876
- Resource Relation:
- Conference: 1. symposium on gages and piezoresistive materials, Archon, France, 29 Sep 1981
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CHEMICAL EXPLOSIONS
PRESSURE MEASUREMENT
REACTION KINETICS
CHEMICAL EXPLOSIVES
DETONATIONS
PETN
TATB
TNT
DECOMPOSITION
DETONATION WAVES
EQUATIONS OF STATE
LAGRANGE EQUATIONS
PRESSURE GAGES
SHOCK WAVES
CHEMICAL REACTIONS
DIFFERENTIAL EQUATIONS
EQUATIONS
ESTERS
EXPLOSIONS
EXPLOSIVES
KINETICS
MEASURING INSTRUMENTS
NITRATES
NITRIC ACID ESTERS
NITRO COMPOUNDS
NITROGEN COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXYGEN COMPOUNDS
PARTIAL DIFFERENTIAL EQUATIONS
450100* - Military Technology
Weaponry
& National Defense- Chemical Explosions & Explosives