| Abstract: | Spatial problems involving the electric field in an MHD channel were formulated in 1] with allowance for the electrode potential drop. It was assumed that the electrode layer had a small thickness, so that relationships on the boundary of the layer could be applied to the surface of the electrode. It was assumed that the electrode potential drop   ° could be represented as a function of the current density jn at the electrode in the form of a known function ° =f (jn) determined experimentally or deduced from the appropriate electrode-layer theory. An approximate method was then put forward for solving such problems by reducing them to the determination of the electric field from a known distribution of the magnetic field and the gas-dynamic parameters. It was shown that when  =°/ E is small (E is the characteristic induced or applied potential difference), the solution can be sought in the form of series in powers of . In the zero-order approximation, the electric field is determined without taking into account the electrode processes. The first approximation gives a correction of the order of . The quantity °, which is present in the boundary conditions on the electrode in the first-order approximation, is determined from the current density calculated in the zero-order approximation.One of the problems discussed in 1] was concerned with the electric current in a channel with one pair of symmetric electrodes. Its solution was found in the first approximation in the form of the integral Keldysh-Sedov formula. In this paper we report an analysis of the solution for ° taken in the form of a step function. |
