Theoretical and Numerical Analysis of High-Explosive Channel Detonation Using Real-Gas Models

The precursor shock wave appearing in high-explosive channel detonation can be prevented at high initial fill pressures as has been previously demonstrated by experiments. However, the theoretical and numerical results from previous works have only achieved qualitative agreement. It was suggested to introduce real-gas equations into the analytical model and numerical simulation to account for the high density, pressure, and temperature nature of the problem. In this thesis, two parametric studies are performed on the ideal gas analytical model developed in previous works, and the parameters being examined are the specific heat ratio (gamma) and the total pressure loss of air and detonation products. The results show that (1) the real-gas effects are important in low air-to-explosive area ratio, and (2) the analytical model has to be modified to include the shock reflections for better predictions. Following the suggestions from previous works, real-gas equations are introduced into the analytical model. The selected equations are the Jones-Wilkins-Lee equation of state (JWL EOS) for detonation products and the polynomials with NASA Glenn coefficients for specific heats in air. An algorithm is developed to determine the critical area ratio at a given initial pressure, and results are similar to the ones from previous works. However, numerical simulations performed by an Euler solver incorporating the JWL EOS for the detonation products show improvement in results and confirmed the real-gas effects are important for the high-explosive detonation studies in small area ratio channels.