Ionization in gaseous detonation waves

Using numerical simulations the spatial and temporal evolution of the electrical conductivity in ionized gas mixtures produced by detonation is investigated in mixtures with and without potassium seeding. Without flow seeding, the magnitude of the electrical conductivity is observed to be too small for significant magnetohydrodynamic forces to affect the conducting flow. This is consistent with past observations. With potassium seeding the electrical conductivity can be increased by 4–5 orders of magnitude, however, a critical percentage of seed particles is observed for which detonation is no longer sustainable. Therefore, there are limits to the electrical conductivity that can be achieved in burned gas mixtures. To further understand the dynamics of the physics involved a parametric study is conducted by varying the ambient pressure, the nitrogen dilution and the potassium seeding percentage. In order to reach these conclusions, a detailed kinetic mechanism of 26 species and 65 reactions has been compiled from the available literature and validated for applications of detonation and ionization chemistry. From the computed mass fractions the mixture-averaged electrical conductivity is then computed.