An analytical study of the plasma conditions and performance of an MHD generator

摘要

In order to investigate the effects of plasma conditions on fluid-dynamical prediction of the performance of an MHD generator, local steady-state calculations are employed. The effective Hall parameter and effective electrical conductivity are estimated by taking the linear theory of ionization instability into account. The results of analytical calculations are compared with experimental ones. Although a fully ionized seed condition, which suppresses instability, provides the highest power generation performance, the condition could be realized only at a high seed fraction in the experiments. It is suggested by the analysis that the fully ionized seed plasma produced at a low seed fraction is desirable in order to achieve high performance. The analysis implies that instability due to insufficient or excessive electron temperatures is a performance-limiting factor. The effects of plasma conditions on performance are clearly explained by the present simple analysis.