Rayleigh-Benard convection

Rayleigh Number

Nusselt Number

total heat flux

conductive heat flux

Turbulent Convection Experimental set up

d = 20 cm Lx =40 cm Ly = 10 cm

Temperature profiles

Nu versus Ra

Heat transport in turbulent convection

When the system is turbulent:

probe

Variable employed for the test

PDF of temperature at Ra=1010

Deviation from a Gaussian as a function of

PDF of temperature at Ra=1010

We select an interval around zero

and we compute

with

We find:

Therefore the temperature PDF verifies

for -0.5<Y<0.5

A good rescaling of the PDF is obatined for all values of

Scaling Function

We modify the Sinai scaling function in the following way: