Effect of Inlet Swirl on Performance of Commercial Scale Disk Magnetohydrodynamic Generator

Abstract

Two-dimensional (r-z) numerical simulation has been carried out to investigate the effects of inlet swirl and applying radio frequency (RF) electromagnetic field on the generator performance of a commercial scale disk magnetohydrodynamic (MHD) generator. With inlet swirl, the fluid work against circumferential Lorenz force is enhanced and the stagnation pressure loss due to joule dissipation is reduced. The enthalpy extraction ratio and the isentropic efficiency are, therefore, improved by inlet swirl. The excessive selfexcited joule heating in the case with inlet swirl is suppressed by applying the RF electromagnetic field, which results in the improvement in the isentropic efficiency. In total, the net enthalpy extraction ratio and the isentropic efficiency are, respectively, improved up to around 29 % and 70 % by inlet swirl and applying the RF electromagnetic field.