HIGH-ENTHALPY EXTRACTION EXPERIMENTS WITH DISK MHD GENERATORS

Power generation experiments have been performed for disk MHD generato rs with different channel shapes. The increase in the enthalpy extract ion ratio by enlargement of the area ratio has been shown experimental ly, and the highest enthalpy extraction ratio of 18.0% was achieved. T he experimental results have shown that for the generator with the lar ge area ratio, the wall static pressure in the MHD channel is kept low er than that for the small-area-ratio generator. These phenomena sugge st that a high Hall parameter is obtained by enlargement of the area r atio. Furthermore, the swirl ratio at the channel exit was measured an d was characterized by the ratio between Hall current and mass flow ra te of the working gas.