PERFORMANCE CHARACTERISTICS OF A SINGLE-WAVELENGTH LIQUID-METAL MHD INDUCTION GENERATOR WITH END-LOSS COMPENSATION

Experiments were performed on a 1000-w, 700-Hz, constant-velocity, alternating-current magnetohydrodynamic (MHD) induction generator using room-temperature sodium-potassium alloy (NaK) as the working fluid. The purpose of the experiments was to determine the electrical losses and power production in the fluid with a winding of the type expected to provide maximum efficiency in the short generators required for low friction loss in liquid-metal MHD power systems. The winding produced a single-wavelength traveling field together with oscillating compensating fields at each end of the generator to cancel the voltage induced between the conducting side-plates by the termination of the traveling field. The efficiency of power generation in the fluid reached 0.54 at a slip s of 0.55, compared with the ideal efficiency (1 + s)-1 = 0.65 of an infinite-length generator. The compensating fields cancelled the sideplate voltage and reduced the electrical end losses in the fluid by a factor of seven. © 1968 American Institute of Aeronautics and Astronautics, Inc., All rights reserved.