Improvement of isentropic efficiency of a magnetohydrodynamic power generator by radio-frequency preionization

We describe the effect of a radio-frequency (rf) power application on the performance of a magnetohydrodynamic (MHD) electrical power generator, as determined through shock-tunnel-based experiments and quasi-three-dimensional numerical simulations. The temporal plasma-fluid behavior, the one-dimensional plasma-fluid structure, the enthalpy-entropy diagram, the quality of the energy conversion efficiency, and the energy flow in the power-generating system are investigated. Preionization assistance by a small amount of rf power drastically changes the entire MHD power-generating system; the MHD extraction length is considerably extended and the isentropic efficiency is significantly improved.