Using ANSYS and CFX to Model Aluminum Reduction Cell since 1984 and Beyond
(References 5, 6 and 7, see Figure 4).
mean that you could plan to use that tool on a routine basis as en efficient design tool!
the development of a first thermo-electro-magnetic model, a 3D thermo-electric full cell and external
busbars model was developed (References 6 and 8, see Figure 5). That model was really at the limit of what
could be built and solved on the available hardware at the time both in terms of RAM memory and disk
space storage.
were mirrored twice. Of course, the converged ledge geometry from the quarter cathode model was used
and kept fixed. Finally, the temperature solution from the quarter cathode model was also forced as
boundary conditions on those cathode elements.
electric solution in the cell reflected the imperfect balance of the external busbars so the electric solution
was different from the forced symmetric solution obtained with the quarter cathode model. In turn of
course, this change in the electric solution should have affected the temperature solution and the converged
ledge thickness. Yet, that coupling had to be neglected as the fully coupled problem could not be possibly
fit in the available computer.
mechanical model
take into account the coupled mechanical response of the swelling lining and the restraining potshell
structure. As the carbon lining swelling due to sodium intercalation is somewhat similar to material
creeping, different models that represented that behavior were developed (References 6 and 9, see Figure
6). However, notice that the most interesting and CPU demanding model has never been published.
pressure from the swelling lining material. Obviously, that additional load needed to be considered in order
to truly design a potshell structure that will not suffer extensive plastic deformation.
is described by the continuity equation, the Navier-Stokes equation and the energy equation. These
equations were solved by the FLOW3D software for a steady state solution. FLOW3D uses the finite
volume approach and hybrid up wind differencing. For turbulence, either the K E model or the differential
Reynolds flux model were used. The geometry and the boundary conditions were the same as those used in
a previous study (Reference 29).
towards the center of the building model. There was a large recirculating loop under the roof and a small
recirculating loop above the center floor opening. The isotherms showed steep temperature gradients near
the cell model with a small peak of 32 °C above one edge of the cell model. The temperatures were almost
constant under the roof.
model (Figure 20). The isotherms show a small peak of 30 °C above the cell model. Both of these
predictions were in good agreement with the experimental data.