NONLINEAR MHD STABILITY OF ALUMINIUM REDUCTION CELLS

An industrial electrolysis cell used for primary aluminium production is sensitive to interface waves between liquid aluminium and electrolyte, which significantly affect the stability of the system. This study aims to address the stability analysis of aluminium reduction cells by incorporating both turbulent horizontal circulation flows in the fluid layers and exploring their implications on oscillation behaviors. A systematic perturbation expansion is used to simplify the problem, allowing for the reduction of the three-dimensional flow dynamics to a two-dimensional context through a shallow water approximation. The Boussinesq formulation extends this modeling to account for more complex wave behaviors including non-linear and dispersive characteristics. The results demonstrate that the inclusion of turbulence modeling is crucial to replicate the self-sustained oscillations observed in actual cells. Additionally, it is shown that balancing vortex formations in both layers can stabilize the interface, providing a viable strategy for improving the design and operational stability of electrolysis cells. The findings emphasize the need for incorporating such turbulence effects in future models to enhance the predictive capabilities regarding cell behavior during production processes.