Gas detonation in a constant-cross-section tube initiated by instantaneous heating at the closed tube end: a simulation for O + O₃ + He mixtures at different He content and closed-end temperatures

Abstract

The one-dimensional problem was studied. A constant-cross-section tube was filled with two gaseous components, A and B, at a fixed initial temperature. The reactants were diluted with the lightest inert gas E (He). The ignition of the reactants and subsequent rapid heating of a closed end of the tube to a certain temperature was followed by the initiation of a reversible reaction A + B ⇄ 2 C involving molecules with considerably different weights (an analog of the only important reaction O + O₃ ⇄ 2 O₂ under the simulation conditions), with the energy thresholds for the forward and reverse reactions. The latter led to realistic values of the rate constant and the heat release for the reaction. All calculations were carried out by the direct simulation Monte Carlo method with variable weight factors on a multiprocessor computer. Molecules were treated as hard spheres with no internal degrees of freedom. It was found that the reaction rate at the leading egde of the detonation wave front is much higher than the equilibrium reaction rate behind the front.