Analysis of real gas effects in an MHD generator with STCC nonuniformities

In the present work, a time-dependent two-dimensional model based on a pressure scheme is presented. It is able to take real gas thermodynamics and loss mechanisms due to friction, heat transport, and turbulence into account. The MHD generation in a current-carrying nonuniform (STCC) regime has been studied by means of it. In order to see what the effects of the loss mechanisms on the STCC-MHD generation are, the results of three different approximations are compared. In the first case, the model analyzes the MHD operation in an ideal gas approximation without losses. In the second case, the ideal gas with losses is studied, in the last one, a combustion gas with loss mechanisms is considered. In all three cases, the same starting conditions and boundary conditions are assumed. Passing from the first to the second case, a reduction of the electrical power output of 20% is calculated. In the third case, with similar plasma conditions, small differences of the power output are obtained. In this case, the energy needed for the formation of the plasma nonuniformity results to be much larger than the energy used in the ideal gases. This is due to the specific heat of the combustion gas, which increases with the temperature