Flow Behavior in a Disk MHD Generator

The flow behavior in a disk MHD generator was studied under high-MHD interaction conditions. Experiments were conducted using a blow-down facility, and argon seeded with cesium was used. The static pressure distribution, the flow velocity, fluctuations of the static pressure and the swirl were measured. The results show that when load resistances and seed fractions are high, a steep pressure increase appears at the upstream region in the MHD channel owing to the enhanced Lorentz force. On the other hand, the location of the pressure increase shifts downstream with the decrease of the Lorentz force. At the same time, the increment of pressure becomes small. A large fluctuation of the static pressure was observed at the upstream region where the steep pressure increase appeared. Characteristics of the pressure fluctuation are found to be analogous to those of the pseudoshock observed in channels without MHD interactions. Furthermore, it is confirmed that the swirl becomes large with the increase of the Hall current.