AN ENERGY ANALYSIS OF UNSTABLE, ALUMINUM REDUCTION CELLS

In this paper we investigate the stability of interfacial gravity wave s in an aluminium reduction cell. Specifically, we use an energy argum ent to unravel the physical mechanisms leading to instability, and to evaluate wave growth rates. In common with other studies, we find that the vertical component of the background magnetic field is central to the instability. Here we show that a key instability mechanism is the generation of oscillatory motion in a direction parallel to the wave crests. This induced, transverse motion is in-phase with the wave pres sure, and so transfers energy into the disturbance.