Europhys. Lett.
Volume 62, Number 6, June 2003
Page(s) 822 - 828
Section Electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics
Published online 01 June 2003
DOI: 10.1209/epl/i2003-00446-x
Europhys. Lett., 62 (6) , pp. 822-828 (2003)

Statistical properties of the fluctuations of the heat transfer in turbulent convection

S. Aumaître and S. Fauve

Laboratoire de Physique Statistique, Ecole Normale Supérieure, UMR 8550 24 rue Lhomond, 75 005 Paris, France

(Received 6 January 2003; accepted in final form 15 April 2003)

We report measurements of the temporal fluctuations of the heat flux in Rayleigh-Bénard turbulent convection in various fluids and geometries. We observe that the rms fluctuations of the heat flux increase nearly proportionally to the temperature difference $\Delta T$. The ratio of the rms fluctuations of the heat flux to their mean display a power law, $Ra^{-\gamma}$ on two decades in Rayleigh number ( $2\cdot 10^7<Ra<3\cdot 10^9$). We discuss this law as well as the non-Gaussian character of the probability density function of the heat flux.

47.27.-i - Turbulent flows, convection, and heat transfer.

© EDP Sciences 2003