Three-dimensional numerical simulation on performance of nonequilibrium plasma MHD generator coupled with radio frequency electromagnetic field

摘要

Three-dimensional numerical simulation has been carried out to investigate the performance of a large scale disk magnetohydrodynamics (MHD) generator coupled with radio frequency (RF) electromagnetic field. The RF technique is verified to be useful for the improvement of performance and widening the actual operating conditions even for a large scale MHD generator. The skin effect of plasma influences the distribution of RF electric field, however, under the present plasma condition in the MHD generator, this effect will not induce the failure of the RF application. When the plasma does not achieve the fully ionized seed condition only by self-induced Joule heating, the plasma is unstable and nonuniform three-dimensionally. Coupling with the RF power can stabilize the plasma and improve the performance of MHD generator. An optimal value of the RF power under which the plasma structure becomes completely uniform in azimuthal direction, and the performance of MHD generator can be most effectively improved is evaluated. The energy cost of RF Joule heating is smaller than the power output increased by coupling with the RF power. The improvement of MHD generator performance by the RF power is efficient.