Performance evaluation of MHD generators: the lumped parameter model and its validation

In this paper, the authors propose a 3D circuital model able to simulate the electrical performance of MHD linear or disk generators. The model consists of an electrical lumped parameter network. On each electrical branch, passive and active elements (such as resistances, controlled or ideal voltage sources) are placed. These bipoles take into account both the electrical characteristics of the ionized gas and all the electrical phenomena within the device (such as Faraday and Hall effects). Then, the equivalent electrical network is completed linking the external loads according to the generator type. On the basis of experimental measurements, some assumptions on fluid dynamics quantities have been imposed in order to define all electrical parameters of the flowing gas. The proposed model has been validated comparing the numerical results both with experimental measurements (on various test facilities) and with various analytical models developed by other researchers. The 3D nature of the model in its simplicity permits to obtain some important information with low cost of calculation