The Rayleigh Benard
instabilities are a phenomena that seems to have various applications.
This study allowed us to visualise many theoretical results about the convection
of Rayleigh Bénard with the simulation code FLUENT. We have shown
that under the critical Rayleigh (Rac=1708), the flow was purely
diffusive (no velocity in the fluid and temperature gradient
linear) and that over the critical Rayleigh, the flow began to be convective
(appearance of convection rolls).
On one hand,
we have checked that the computation of Rac was in good agreements with
the theoritical prediction. We also checked that the unsteady calculations
tend to the results of the steady model, if time increases. On the other
hand, we tried to draw users' attention on the results given by FLUENT.
For that, we have taken a turbulent case and calculated it with both laminar
and turbulent models. All these results do not bring something really knew
about the Rayleigh Benard instabilities but let the users of FLUENT know
better the results they get and what they can conclude from them.