Effects of Total Pressures on Performances of a Disk MHD Generator

Effects of total pressures on performances of a disk MHD generator were studied. Current-voltage characteristics, power outputs, distributions of both static pressure and Hall potential and swirl were measured at two different total pressures. The experimental results show that at the low total pressure, the current-voltage characteristics become steep, and as a result, the maximum power output is obtained at higher load resistances. It was observed that the enthalpy extraction rate was kept almost constant although the power output decreased at the low total pressure. These phenomena can be explained by the change of the Hall parameters, flow velocities and swirls in the MHD channel.