AbstractThe experiments of pre‐ionized inert gas plasma MHD electrical power generation are conducted, and the performance and plasma behavior in the experimental generator are examined through time‐dependent r‐_ two‐dimensional numerical simulation. In the experiment, an enthalpy extraction ratio of 4.01% has been obtained with a disk‐shaped MHD generator with radio‐frequency pre‐ionization. In the numerical simulation, at an assumed inlet electron temperature around 5600 K (inlet ionization degree 0:10 × 10−4)_6600 K (1:36 × 10−4), the plasma structure is similar to the non‐uniform structure observed in the experiment. An enthalpy extraction ratio around 2_5% matches well with that in the experiment. At a suitable inlet electron temperature of 7000 K (3:15 × 10−4)_8000 K (1:79 × 10−3), although non‐uniform plasma structure still occurs, a high enthalpy extraction ratio over 10% is expected.