Flow of Liquid Metals with a Transversely Applied Magnetic Field : 7th Report, Experiment on the Unsteady Channel Flow

It is considered that transfer, control and measurement of molten metals by MHD devices are very important for automation in casting and metallurgical industries. From such a practical standpoint, investigations on MHD channel flows of liquid metals seem to be fully significant in engineering. However the experimental investigations on the unsteady MHD channel flows are few. This report deals with the experimental investigation on the transient flow of mercury in a rectangular channel. A constant magnetic field or constant magnetic and electric fields are suddenly applied in the direction perpendicular to the flow, being initially hydrodynamic, and the created electromagnetic effects modify the motion to give rise to a magnetohydrodynamically developed flow. Then the applied fields are suddenly removed from the magnetohydrodynamically developed flow. It is shown that the flow undergoes oscillations during the transition from hydrodynamic to magnetohydrodynamic conditions or from magnetohydrodynamic to hydrodynamic ones and that the time required for the transient flow to reach the steady state is longer in the region of transitional flow.