Numerical Analysis of Generator Performance of Experimental DCW-MHD Generators with Circular and Square Cross-Section

The purpose of this study is to examine the influence of shape of cross-section of scramjet engine driven experimental DCW-MHD generator on generator performance by threedimensional numerical analyses. We have designed the MHD generators with symmetric square and circular cross-section, based on the experimental MHD generator with asymmetric rectangular cross-section. In the optimum load condition, the electric power output becomes 26.6 kW for the asymmetric cross-section, 24.6 kW for the symmetric square cross-section, and 22.4 kW for the circular cross-section. The highest output is obtained for the experimental generator with asymmetric cross-section. The boundary layer becomes the thinnest for the asymmetric cross-section and does the thickest for the circular cross-section. The difference of boundary layer thickness is almost unrelated to applying the magnetic field, and influences the fluid velocity, the electrode voltage drop and the effective generation volume.