| Explosive detonation products typically consist of high pressure, high temperature gases, whose composition can be fuel rich, fuel lean, or balanced. Afterbuming occurs when fuel-rich detonation products react with oxygen in the surrounding atmosphere, and can further contribute to the air blast, resulting in a more severe explosion hazard, particularly in confined scenarios.;Prediction of the arrival times of shock waves in a confined blast scenario is challenging to all numerical codes. The primary objective of this project was to investigate the influence of the products equation of state on the prediction of the efficiency of TNT afterburning and the times of arrival of reverberating shock waves in a closed chamber.;A new equation of state was proposed, denoted the Afterbuming EOS. This equation of state employs the JWL EOS in the high pressure regime, transitioning to a Variable-Gamma EOS at lower pressures. Simulations of two TNT charges suspended in a 26 m3 explosion chamber were performed. When compared to numerical results using the existing methods, it was determined that the Afterburning EOS delays the shock arrival times giving better agreement with the experimental measurements in the early to mid time. In the late time, the Afterbuming EOS roughly halved the error between the experimental measurements and results obtained using existing methods. However, the agreement with the transient late time pressure signals did not significantly improve.;The assumption that soot particles in the detonation products were in perfect equilibrium with the fluid was investigated, and a high resolution simulation showed the minimal effect of diffusion on the simulation results. Finally, the Afterbuming EOS was used in the simulation of two C4 charges to determine if the method could be applied to other explosives. Results showed similar trends to those of the TNT study. However, the more significant difference with the experimental results was shown to be potentially due to additional energy input from the combustion of the casing material. |
