Plasma Characteristics and Performance of Magnetohydrodynamic Generator With High-Temperature Inert Gas Plasma

We describe magnetohydrodynamic power generation experiments with seed-free high-temperature inert gas plasma using a linear-shaped Faraday-type generator driven by a shock-tunnel facility. The influence of inlet total temperature between 6500 and 9000 K on the plasma characteristics and its influence on generator performance are shown. By increasing the inlet total temperature, streaky and unstable plasma, characterized by large fluctuations in power output, is transformed into homogeneous and stable plasma, providing stabilized and improved power output. A quasi-1-D numerical simulation suggests that the plasma in the generator undergoes recombination when the inlet total temperature is high, which might be a factor in plasma stabilization. At the optimum load resistance, the enthalpy extraction ratio is improved to 12.9%; the optimum load resistance decreases as inlet total temperature is increased by the increase in electrical conductivity.