Factors Effecting the Performance of Diagonal Conducting Wall Open Cycle MHD Generators

Abstract : A systematic study has been undertaken to attempt to evaluate gross factors effecting the overall performance of series connected generators. These factors include combustor performance, chemistry, magnetic field strength, Mach number, and electrode segmentation. The scaling law for the magnetic field is of the form (B - V sub d/ud) squared. Dimensional scaling was investigated by varying the segmentation ratio of electrode length to channel height. The results show that when the electrode length divided by the channel height is changed from the neighborhood of .12 to the neighborhood of .25 then the generator power output decreases by 15 percent over the entire load spectrum. Other studies involving gross generator behavior include an investigation of the effect resulting from the deposit of aluminum oxide and other combustion materials on the walls of the generator. No deterioration of performance was noted during this process. The addition of the powdered aluminum improved the generator performance. During the course of the experimental study, it was found that both the injector head and combustor are very critical to the performance of the generators.