Full Program »

Lagrangian measurements of temperature and velocity in turbulent thermal convection

PDF
0.3MB

We introduced a neutrally buoyant Smart Particle able to measure the local temperature in a Rayleigh-Bénard flow. The aim is to understand organisation of heat flux transport in turbulent thermal convection. We perform measurements for Ra=3.10^10, 4.10^10 and 5.10^10. As expected for a Lagrangian tracer in a turbulent flow, the velocity power spectra show a scaling range close to f^{-2}. The probability density functions of temperature are clearly non gaussian while the power density spectra exhibit a scaling close to f^{-2.5} which seems to indicate that temperature is not a passive scalar and probably dominated by the large scale flow behavior.

Author(s):

Olivier Liot    
Ecole Normale Supérieure de Lyon
France

Fanny Seychelles    
Ecole Normale Supérieure de Lyon
France

Julien Salort    
Ecole Normale Supérieure de Lyon
France

Eleonore Rusaouen    
Ecole Normale Supérieure de Lyon
France

Marius Tanase    
Ecole Normale Supérieure de Lyon
France

Francesca Chillà    
Ecole Normale Supérieure de Lyon
France

Bernard Castaing    
Ecole Normale Supérieure de Lyon
France

Yoann Gasteuil    
Ecole Normale Supérieure de Lyon
France

Jean-François Pinton    
Ecole Normale Supérieure de Lyon
France