An experimental study of the effects of large longitudinal magnetic fields on the pipe flow of mercury has been made. The experiments were designed to provide large magnetic interaction parameters and thereby to have an important effect upon transition from laminar to turbulent flow and upon the structure of any turbulence. The friction factor and the transition Reynolds number were measured as functions of the magnetic field strength. The friction factor was obtained from accurate measurement of the pressure gradient along the tube. The transition Reynolds number was determined from measurements of the intermittency factor obtained using a hot-wire anemometer.
The results indicate that all relevant stability theories vastly over-estimate the stabilizing effect of the field. The results also indicate that viscosity plays a critical role in delaying transition and in reducing the friction factor of fully developed flows. This, in turn, leads to the important conclusion that the magnetic field has an important effect on the generation of new turbulence, as well as upon the damping of already generated turbulence.