Abstract
Subsonic flows near sonic condition have strong nonlinearities. For example, a slight variation of load condition of a subsonic MHD generator often causes a transition from a subsonic flow near sonic condition into a transonic flow with choking and shock wave. In the present paper the choking phenomena in MHD channels are investigated in order to analyze the nonlinear properties of subsonic MHD generators. The choking point is classified into two kinds by its geometrical property; one of them can appear in the MHD channel, whereas the other cannot appear in the channel and exists at the channel exit. A method of steady state analysis for transonic flow with choking and shock wave considering downstream condition is presented. A steady state analysis of a subsonic diagonal type MHD generator shows that transitions between subsonic flows and transonic flows are often accompanied with bifurcation phenomena such as hysteretic behavior of the flow and jump behavior of the power output.
