Quasi-static pressure calculations of confined explosions

Abstract

Based on the state equation of ideal gas, thermodynamics and some laws of physical chemistry, a formula for the quasi-static pressure of a confined explosion was derived, when the chemical reactions and energy conversion of the detonation products were considered, and the expansion process of the detonation products was under constant entropy. Taking trinitrotoluene (TNT) explosive as an example, the chemical reaction kinetics of the detonation products, with different explosive charge volume ratios, was analysed. A program, named Chemical Reaction Kinetic Numerical Computation and Application (CRKNCA), was written, which could calculate the quasi-static pressure of TNT explosives in confined rooms. Comparing the calculated results of the program with the experimental data, as well as the results of the Conventional Weapon Effects Program (CONWEP) and the simulation results by fluid dynamics under similar conditions, the accuracy of the formulas proposed in this paper was verified. Moreover, it was concluded that the chemical reactions of the detonation products had an important influence on the quasi-static pressure of confined explosions.