Affiliation:
1. Central Electricity Research Laboratories, Cleeve Road, Leather-head, Surrey.
Abstract
A discussion is given of the basic physical processes occurring in magnetohydrodynamic (MHD) generators. In designing a generator two parameters are of importance, namely, the power output per unit volume and the isentropic efficiency ñs which is a measure of the departure of the generation processes from the ideal. It is shown that the maximum electrical output per unit volume of gas is ñs(1-ñs)θ u2 B2 where θ is the electrical conductivity, u the flow speed down the duct, and B the magnetic field strength. The paper describes how the isentropic efficiency depends on the load characteristics, how to calculate the electrical conductivity, the effect of a strong magnetic field on the electrical conductivity and the optimum shape of an MHD duct. A brief account is given of the progress in the development of experimental generators and of the practical problems still to be solved.