Two Dimensional Analysis of Faraday Type Linear Diverging Combustion Gas MHD Generator

Abstract

In this paper the authors investigate the effects of non-equilibrium ionization in the cool gasdynamic boundary layer in a combustion gas MHD generator. A two dimensional analysis is applied to the linear diverging Faraday type channel, and predicts that the current concentrates near the electrode edges and Hall current in the core is positive in the case neglecting the boundary layer. However, the current consentration is almost diminished and the Hall current in the core becomes negative in the case considering the effect of nonequilibrium ionization in the cold boundary layer. Also, it is clarified that at the condition of wall temperature Tw ＝ 1500 K, the generator output power in a nonequilibrium case is about ten times larger than that in an equilibrium case. Apparent conductivity, apparent Hall parameter, power density, and local conversion efficiency are calculated and detailed discussions on these quantities are made.