Influence of Asymmetric Placement of Radio-Frequency Induction Coil on Performance of Nonequilibrium MHD Generator

Abstract

The authors conduct a two-dimensional (r-z) MHD numerical simulation for examining the influence of asymmetric placement of radio-frequency (rf) induction coil on the generator performance of a commercial scale, large nonequilibrium disk-shaped MHD generator with an rf preionization technique. The MHD numerical simulation is carried out under two different placement conditions of rf induction coil: one is that an rf induction coil is placed on only one side disk wall and the other is that it is symmetrically placed on each of both disk walls. Numerical results show the performance of MHD generator with one-sided rf induction coil placement inducing an asymmetric rf electromagnetic (EM) field is comparable to that of the MHD generator with both-sided rf indction coil placement inducing a symmetric rf EM field, although the one-sided induction rf coil placement causes an asymmetric distribution in the z-direction of plasma properties such as electron temperature and ionization degree near the rf induction coil.