Abstract
The electric potential drop near the electrode surfaces in MHD power generators is studied theoretically by considering a simple model, in which the current flows in the direction normal to the electrode surfaces. In order to simplify the situation so as to permit analytic solution, the idea of a "boundary layer" near the electrodes is introduced, and the problem is treated entirely macroscopically, wherein the following assumptions are made:
(1) The electrical conductivity is constant.
(2) The Hall effect and the induced magnetic field can be neglected.
(3) The behavior of the flow in the boundary layer may be described by equations for laminar flow.
(4) The temperature variation in the boundary layer perpendicular to the electrode surfaces may be neglected.
The theory predicts that the magnitude of the electric potential drop near the electrode is of the order of 10 V in typical MHD power generators.
