The calculation methods for nonsteady flows with the shock waves in the channels of the MHD-generators

Survey of important methods used for the calculations of the nonsteady flows with the shock waves in the MHD-generator is presented. The results of the calculations of nonsteady flow caused by the change of the generator load are given. The calculations were done for the gasdynamic duct containing Laval nozzle and MHD generator of Faraday type with segmented electrodes and diffuser. Constant mass flow ratio and stagnation temperature in the inlet of the nozzle as well as constant pressure on the outlet of the diffuser were assumed. Lax-Wendorff differential scheme together with Neuman-Richtmyer artificial viscosity method and differential scheme of Mac Cormac were used. It was noticed that joint application of Lax-Wendorff scheme and Neuman-Richtmyer artificial viscosity method gives the better attenuation of the high frequency oscilations, which are rather pertained to the shock wave head, than the Mac Cormac scheme. Mac Cormac scheme ought to be used together with Neuman-Richtmyer artificial viscosity method. Computer code NEPTUN used for the calculation is described. (author)