학술논문

Thermodynamic States in Explosion Fields
Document Type
Conference
Author
Source
Conference: Presented at: 14th International Detonation Symposium, Coeur d' Alene, ID, United States, Apr 11 - Apr 16, 2010
Subject
71 CLASSICAL AND QUANTUMM MECHANICS, GENERAL PHYSICS AIR
CLOUDS
COMBUSTION
COMBUSTION PRODUCTS
COMBUSTION PROPERTIES
DENSITY
ENTROPY
EXPLOSIONS
EXPLOSIVES
GASES
OXYGEN
REACTION HEAT
SPECIFICATIONS
THERMODYNAMICS
Language
English
Abstract
Here we investigate the thermodynamic states occurring in explosion fields from the detonation of condensed explosives in air. In typical applications, the pressure of expanded detonation products gases is modeled by a Jones-Wilkins-Lee (JWL) function: P{sub JWL} = f(v,s{sub CJ}); constants in that function are fit to cylinder test data. This function provides a specification of pressure as a function of specific volume, v, along the expansion isentrope (s = constant = s{sub CJ}) starting at the Chapman-Jouguet (CJ) state. However, the JWL function is not a fundamental equation of thermodynamics, and therefore gives an incomplete specification of states. For example, explosions inherently involve shock reflections from surfaces; this changes the entropy of the products, and in such situations the JWL function provides no information on the products states. In addition, most explosives are not oxygen balanced, so if hot detonation products mix with air, they after-burn, releasing the heat of reaction via a turbulent combustion process. This raises the temperature of explosion products cloud to the adiabatic flame temperature ({approx}3,000K). Again, the JWL function provides no information on the combustion products states.