Ann. Phys. Fr.
Volume 19, Number 6, 1994
|Page(s)||739 - 741|
|Published online||01 June 2004|
Etudes des instabilités thermiques dans un écoulement ouvert horizontal, soumis à un phénomène de convection mixte
I.U.S.T.I. (U.R.A. CNRS n° 1168) Université d'Aix-Marseille I, Centre de Saint Jérôme, 13397 Marseille cedex 20, France
This study deals with thermal instabilities appearing on a "laminar-turbulent" transition. They are considered for a flow in a cylindrical and horizontal duct uniformly heated at the wall. Temporal fluctuations of the wall temperature represent these instabilities. After presenting characteristic and experimental results, we will carry out a signal analysis corresponding to the variations of this temperature. This will help us outline and describe the mechanisms that appear when these instabilities occur.
PACS : 4725Q – Convection and heat transfer / 4715F – Stability of laminar flows / 4760 – Flows in ducts, channels, and conduits / 4720 – Hydrodynamic stability and instability
Key words: convection / flow instability / laminar to turbulent transitions / pipe flow / thermal instabilities / laminar turbulent transition / horizontal duct / cylindrical / mixed convection / wall temperature
© EDP Sciences, 1994