Detonation properties of gases at elevated initial pressures

The detonation properties of several gaseous systems at elevated initial pressures were examined theoretically. The systems investigated include: hydrogen (H-2), methane (CH4), ethylene (C2H4), ethane (C2H6), and propane (C3H8). Chemkin Real Gas, a computer program capable of calculating real-gas thermodynamic properties and chemical kinetic reaction rates, was expanded to utilize the ideal gas, van der Waals, Redlich-Kwong, Soave, and Peng-Robinson equations of state to describe the P-V-T behavior of the gaseous mixtures used in this investigation. The Chapman-Jouguet (CJ) theory of detonation was used to examine the variation of the detonation properties as a function of the initial pressure and temperature. The CJ numerical calculations are shown to be relatively insensitive to; equation of state dependent constants (critical properties) estimated for the radical species present in the detonation products. The real-gas equations of state are shown to accurately predict the variation of the experimentally measured detonation velocities with initial pressure.