Plasma Fluid Flow Behavior and Power Generation Characteristics in a High-Temperature Inert Gas Plasma Faraday Type MHD Generator

Plasma Behavior in a High‐Temperature Noble Gas Plasma Disk‐Shaped MHD Power Generator

“…This is consistent with the conclusion drawn by Hougen and colleagues. With higher inlet total temperature, the ionization degree of plasma flowing into generation channel becomes higher, and Coulomb collisions of electrons prevail, which was indicated as a factor for plasma deviation from Saha equilibrium state and suppression of ionization instability [10]. Here, there is one wave of ionization degree and two waves of electron temperature, and the one wave of ionization degree propagates between the two waves of electron temperature.…”

“…(1) Plasma stabilization by increase in inlet total temperature As regards plasma stabilization by increase in inlet total temperature in high-temperature noble gas plasma MHD power generation, this phenomenon was also confirmed by two-dimensional nonstationary numerical analysis of Faraday-type generators. With higher inlet total temperature, the ionization degree of plasma flowing into generation channel becomes higher, and Coulomb collisions of electrons prevail, which was indicated as a factor for plasma deviation from Saha equilibrium state and suppression of ionization instability [10]. Figure 7 shows the inlet total temperature dependence of the ratio of electron collision frequency with ions and neutral particles inside generation channel at load resistance of 2 Ω.…”

“…It was shown that power generation performance equal to or higher than that of seed-plasma scheme could be achieved. It was suggested that the deviation of plasma inside the generator from Saha equilibrium and the dominating state of Coulomb collisions of electrons serve to suppress ionization instability and stabilize the plasma [10]. Especially, as regards numerical analysis of Faraday-type generator, the experimentally observed nonuniform plasma structure at low inlet total temperature and plasma homogenization with the increase in inlet total temperature were investigated.…”

“…It was shown that power generation performance equal to or higher than that of seed-plasma scheme could be achieved. There are also examples of r-z twodimensional numerical analysis of disk-shaped Hall-type generator [7] and x-y two-dimensional numerical analysis of linear-shaped Faraday-type generator [10]. Especially, as regards numerical analysis of Faraday-type generator, the experimentally observed nonuniform plasma structure at low inlet total temperature and plasma homogenization with the increase in inlet total temperature were investigated.…”

“…Especially, as regards numerical analysis of Faraday-type generator, the experimentally observed nonuniform plasma structure at low inlet total temperature and plasma homogenization with the increase in inlet total temperature were investigated. It was suggested that the deviation of plasma inside the generator from Saha equilibrium and the dominating state of Coulomb collisions of electrons serve to suppress ionization instability and stabilize the plasma [10].…”