Coupled electrical and fluid calculations in the cross plane in linear MHD generators

Two dimensional aspects of the coupling between the quasi-three dimensional fluid and electrical equations are presented. It is shown that significant Hall current-induced secondary flows can exist even in Faraday generators. These secondary flows can dominate the turbulence-related secondary flows induced by noncircularity of the duct cross section. Insulator wall velocity overshoots and friction enhancements caused by nonuniform plasma properties are predicted in agreement with previous work. For conducting wall generators, the velocity overshoots can extend over the electrodes as well. The conducting wall generator also exhibits a tendency for current constriction on the sidewall at high values of the Hall parameter. The predicted phenomena are compared to experimental experience with slag deposition patterns and conducting wall sidebar damage.