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

The effects of area ratio on electrical and fluid-dynamical properties in a disk magnetohy-drodynamic (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 the small area ratio generator. It is observed that high values of the Hall field are obtained at the downstream part of the channel which has a 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 is found that in pressure loss processes a strong Lorentz force becomes quite significant relative to the wall friction which plays a major part in the pressure loss mechanism in the absence of MHD interaction.