Flow in Direct-Current Electromagnetic Pumps

The effects of the ends of the electric and magnetic fields on the steady one-dimensional channel flow of an electrically conducting fluid were studied experimentally and theoretically. Two methods are described which may be used to recover the one-dimensional character of the flow. It was found possible to obtain an electric field that is essentially one-dimensional, by choosing the center portion of the field produced by very long electrodes for the location of a rectangular magnetic field. Flow from such a pump, where the end effects are negligible, is evidenced by the uniformity of the stream. The disadvantage of this pump is that only about one-third of the current interacts with the magnetic field to increase the momentum of the stream. (B.O.G.)