At the end of the last century, Rayleigh studied strange instabilities.
These instabilities appear for a configuration such as:
A viscous fluid lies between two walls with a gradient of temperature.
It may happen different cases:
- if T1>T2, the temperature field is given by Fourier's law, in other words the temperature is linear such as :
- if T1<T2, for certain conditions, the gradient of temperature can make the state of the fluid change and create a velocity field between the walls. This phenomenon is called Rayleigh-Benard instability.