Plasma Characteristics and Performance of Nonequilibrium Disk Magnetohydrodynamic Generator with Swirl Vanes

Abstract

Two-dimensional () numerical simulations of a nonequilibrium disk-shaped magnetohydrodynamic generator with swirl vanes were conducted to clarify the influences of electrical conductivity of swirl vanes and wakes induced by the swirl vanes on plasma flow and generator performance. The working gas was assumed to be helium seeded with cesium vapor. The thermal input to the magnetohydrodynamic generator and the strength of the applied magnetic field were set to 11 MW and 3 T, respectively. The swirl vanes were assumed to be made of either electrically conductive or insulated material. Low magnetic Reynolds number magnetohydrodynamic equations coupled with a conventional two-temperature plasma model were used for the simulations. The numerical results showed that the electron temperature and electrical conductivity of the plasma in the region between vanes for the conductive vanes were higher than those for the insulated ones. The differences between the two cases, however, rapidly disappeared right after the plasma passed through the region between vanes. Consequently, the swirl vane’s electrical conductivity hardly influenced the generator performance. The numerical results also demonstrated for the first time that the inside and the vicinity of the wakes had either low-power-output densities or negative ones corresponding to power consumption.