Abstract
Effects of an area ratio on performances of closed cycle disk MHD generator with cesium seeded argon were studied experimentally. Experiments were carried out by using a shock-tube driven disk MHD generator with a small area ratio. Enthalpy extractions, radial distributions of Hall potential and static pressure, stagnation pressure loss and adiabatic efficiencies were measured. It was found that the adiabatic efficiency increases remarkably with a decrease of the area ratio although the enthalpy extraction decreases. The adiabatic efficiency of 40.5% was obtained and it was the highest compared with previous experiments with the cesium seeded argon. Relations between the adiabatic efficiency and the enthalpy extraction were also studied. Measured relations coincided well with those predicted by a simple analysis and effects of fluid-dynamical boundary layer on the relations were found small even in the present small disk MHD channel. Furthermore, it is suggested that an achievement of high Hall coefficient and a decrease of wall friction are important to improve the disk MHD generator performances.
