Gasdynamic performance in relation to the power extraction of an MHD generator

An experimental and theoretical study of gasdynamical processes in an MHD generator is presented. The measured profile of the static pressure strongly increases in the second half of the experimental generator, due to thick boundary layers. A core flow and boundary layer model and a quasi-one-dimensional computer code are used for the theoretical part. It is shown that the boundary layers have to be calculated from integral equations describing the momentum, kinetic energy, and stagnation enthalpy, taking MHD effects in the boundary layers into account. The calculations show that the electrical power output is limited by the design of the studied facility and indicate possibilities of circumventing this limitation. The model also indicates shortcomings in the operation of the generator, especially a limitation caused by Hall shorting.