Experimental investigation of a diagonally connected closed-cycle MHD generator

An insulating sidewall diagonally connected MHD (magnetohydrodynamics) channel has been tested, and the experimental data have been analyzed. Power outputs of up to 330 kWe have been observed. The nearly linear shape of the I-V characteristic of the generator indicates a stable generation at any load. Through the experimental data the electrical parameters have been derived and an empirical model of the plasma has been set up. The experimental results are compared with the results obtained by means of a quasi-one-dimensional model when using the empirical plasma model mentioned above, and with a theoretical model which utilizes reduction formulas derived on the basis of the instability theory. Good agreement between the empirical model and the experiments is shown. The theoretical model tends to overestimate the electrical power. An analysis of the fluctuations shows a constricted discharge regime at any operating condition. The current density inside a discharge is constant and is approximately equal to 50 A/cm², irrespective of the operating conditions