Temperature and Physical Properties of Combustion Gases in MHD Generators

Results of investigations of temperature, composition, state of ionization, and other physical properties of seeded combustion gases flowing in an MHD generator are presented. Influences of heat lost by cooling the combustion chamber and duct, the heat absorbed in vaporizing and heating water and seed, and the dissociation of seed are considered, as are the electrical properties and state of ionization. In particular the hydrogen content of the fuel is found to affect the electrical conductivity of the plasma in that the OH radicals formed act both as electron absorbers and as traps for potassium ions in the plasma, forming the relatively stable compound KOH. The principles of formulating the non-linear problem for plasma temperature and composition are given. Groups of equations characterizing dissociation, ionization and formation of negative ion reactions in plasma, and the energy balance equations are presented. Various mixtures of fuel/oxidizer/seed are considered in the subsequent calculations, the results of which are given in a form suitable for solving design problems on open-cycle MHD generators of this type. (author)