High Enthalpy Extraction Experiments with Disk MHD Generators

MHD power generation experiments have been performed for disk-type generators with different channel shapes. The increase in the enthalpy extraction ratio due to enlargement of the area ratio has been shown experimentally and the highest enthalpy extraction ratio of 18.0% was achieved. The experimental results have shown that for a generator with a large area ratio, the wall static pressure in the MHD channel is kept lower than that for a small area ratio generator. These phenomena suggest that a high Hall parameter is obtained by enlargement of the area ratio. Furthermore, a swirl ratio at the channel exit was measured and was characterized by the ratio of the Hall current and the mass flow rate of the working gas.