Power density and electrical efficiency in closed cycle MHD generator with fully ionized seed

Effects of a reduced seed concentration on performances of a nonequilibrium MHD generator are investigated by calculating power densities and electrical efficiencies for both Faraday and Hall generators. It is shown that high electrical efficiencies and high power densities are obtained simultaneously by suppressing the ionization instability with reduced seed fractions (10-4 -- 10-5) when values of the effective electrical conductivity and the effective Hall parameter recover to above 50% of their ideal ones. Results also indicate that argon is more suitable for a working fluid than helium in the case of a reduced seed concentration. (auth.)