Numerical simulation of non-equilibrium effects and ionization in H ₂-air detonations

The study of plasma creation in detonations and the effects of chemical and thermal nonequilibrium on the detonation structure and stability are addressed. The primary objective is to analyze the production of electrons and ions in the explosion products to determine where the conduction zone exists in relation to the detonation front and to quantify the plasma by its electrical conductivity and magnetic Reynolds number, which are important parameters for the design of contact gauges, MHD generators and other applications using detonation. A H ₂-air detonation is first simulated using a kinetic model considering 9 species and18 elementary reactions. This initial two-dimensional investigation demonstrated that the temperature of the explosion products was high enough for ionization to be significant. A kinetic model for the charge exchange reactions, associative ionization reactions, electron-impact dissociation and electron-impact ionization governing the production of plasma in the explosion products was coupled with the combustion kinetics. A total of 18 species and 83 elementary reactions were considered.