European Turbulence Conference 2015

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11:45
15 mins

Roughness-triggered turbulent boundary layers in Rayleigh-Bénard convection
Julien Salort, Olivier Liot, Robert Kaiser, Ronald du Puits, Francesca Chillà

Session: Thermally driven turbulence 1
Session starts: Thursday 27 August, 10:30
Presentation starts: 11:45
Room: Room I

Julien Salort (Laboratoire de physique, ENS Lyon CNRS)
Olivier Liot (Laboratoire de physique, ENS Lyon CNRS)
Robert Kaiser (TU-Ilmenau, Institute of Thermdynamics & Fluid Mech.)
Ronald du Puits (TU-Ilmenau, Institute of Thermdynamics & Fluid Mech.)
Francesca Chillà (Laboratoire de physique, ENS Lyon CNRS)

Abstract:
We present measurements carried out inside the Barrel of Ilmenau as part of the European EuHIT transnational infrastructure access program. The Barrel of Ilmenau is the worldwide largest experiment to study highly turbulent convection in air. A rectangular cell, with proportions strictly identical to the water cell in Lyon [Salort, et al. PoF 26:015112 (2014)], but six times larger, has been inserted inside the Barrel. The top plate is smooth, and the bottom plate is rough. The roughness are also similar to the one in Lyon, but six times larger. We have obtained velocity fields using PIV near the obstacles, as well as the local heat-flux on the bottom plate. This has allowed us to test and improve our previous interpretation of the roughness-induced heat transfer enhancement mechanisms.