Volume 87, Number 4, August 2009
|Number of page(s)||6|
|Section||Electromagnetism, Optics, Acoustics, Heat Transfer, Classical Mechanics, and Fluid Dynamics|
|Published online||15 September 2009|
Transition on local temperature fluctuations in highly turbulent convection
Institut Néel, CNRS/UJF - BP 166, F-38042 Grenoble cedex 9, France, EU
2 Technische Universität Ilmenau - Ehrenbergstraße 29, D-98693 Ilmenau, Germany, EU
Accepted: 13 August 2009
In 1997, a new turbulent regime has been observed in a Rayleigh-Bénard cell and has been interpreted as the “Ultimate Regime” of convection. This observation was based on global heat transfer measurements at very high Rayleigh numbers (Ra). Using a set-up similar to the one used in 1997, we examine the signature of this regime from within the flow itself. A systematic study of probe-size corrections shows that the earlier local temperature measurements within the flow were altered by an excessive size of thermometer, but not according to a theoretical model proposed in the literature. Using a probe one order of magnitude smaller than the one used previously, we find evidence that the transition to the very-high-Ra regime is indeed accompanied with a clear change in the statistics of temperature fluctuations in the flow.
PACS: 47.27.te – Turbulent convective heat transfer / 44.25.+f – Heat transfer: Natural convection / 47.80.-v – Instrumentation and measurement methods in fluid dynamics
© EPLA, 2009
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.