Supersonic Flow Behavior under Strong Lorentz Force : Effects of Area Ratio and Pressure Loss

Abstract

The effects of area ratio on electrical and fluid-dynamical properties in a disk magnetohydrodynamic (MHD) generator have been experimentally investigated. The experimental results have shown that for a generator with a large area ratio, the wall static pressure is kept lower than that of a small-area-ratio generator. It is observed that high values of the Hall electric field are obtained at the downstream part of a channel with large area ratio. The stagnation pressure at the exit of the disk MHD channel was measured and compared with the results of one-dimensional calculations. It was found that in pressure loss processes a strong Lorentz force becomes quite significant relative to wall friction which plays a major part in the pressure loss mechanism in the absence of MHD interaction.