Survey of twenty years of modelisation of the MHD stability in Aluminium Electrolysis By Michel Romerio, Senior Researcher, EPFL, Lausanne Michel Romerio, a physicist by formation has worked for twenty years with Alusuisse and now with ALCAN, developing the numerical simulation of Aluminium electrolysis pots. This is a complex multi physics process that includes Joule effects, convection and magneto-hydrodynamics. It also involves stability of free surfaces, and much more. The process must be designed to avoid damages to the pots as well as optimal energy requirements. The EPFL team has had and still has a unique industrial collaboration with the aluminium producer and R/D lab. The conference will overview the work done, and the state of the art today. For a presentation of the problem and example see : http://dmawww.epfl.ch/rappaz.mosaic/research/alu.html http://dmawww.epfl.ch/rappaz.mosaic/animations/alu.html