DETONATION-WAVE STRUCTURE OF GASES AT ELEVATED INITIAL PRESSURES

The characteristic ''structure'' of gaseous detonation waves, defined here as the spatial variation of the pressure, temperature, density, s pecies concentrations, and velocity within the detonation wave is exam ined theoretically at elevated initial pressures. The approach taken i n this work is to extend the Zel'dovich-von Neumann-Doering (ZND) theo ry of gas-phase detonation to use real-gas equations of state. Chemkin Real Gas, a computer program capable of calculating real-gas thermody namic properties and chemical kinetic reaction rates, is used to descr ibe the P-V-T behaviour of the gaseous mixtures in this investigation. The mathematical model for a ZND detonation wave is presented in an e quation of state independent form and integrated numerically for a hyd rogen-oxygen system to determine the structure of the detonation wave. The ZND model is used to characterize the thermodynamic states and re action zone length scales present in the detonation wave. The variatio n of the reaction zone length parameters is examined as a function of the initial pressure, temperature, and composition. The distance from the shock front to the maximum temperature derivative is shown to be a reproducible reference location in the detonation wave structure. The numerical calculations exhibit sensitivity to equation of state depen dent constants and pre-exponential rate coefficients in the elementary reaction mechanism.