Numerical study of the effect of the Hall phenomenon on Supersonic ۲D flow in a MHD generator

Abstract

This research studies the effect of the Hall Effect and the geometry numerically on the supersonic, steady and compressible air flow in a magneto-hydrodynamic (MHD) generator. The flow is considered as a perfect gas with a low magnetic Reynolds number. The considered geometry is a two-dimensional channel with four pairs of electrodes and various geometries including constant cross-sections, convergent, divergent and divergent-constant sections channels. The results indicated that Mach angle in the fixed channel is lower than the other geometries and the output electric power and the electrical efficiency along with the output pressure in the fixed channel are higher than those of other geometries. Also, the Hall Effect reduces the output pressure and joule heating, while increases the electrical efficiency across all channels by preventing the reduction of the plasma flow due to the magnetic field. Considering the feasibility of using MHD generator, various results, in particular Joule heating resulting from of the Krypton gas flow and air flow, are compared. The comparison suggested that the joule heating of the Krypton gas is lower than air and the Krypton gas can be recommended as a proper gas to be used in the MHD generators.