Hostname: page-component-7b7567c8c-fvjsw Total loading time: 0 Render date: 2026-11-15T09:01:59.296Z Has data issue: false hasContentIssue false

Convective/absolute instability in miscible core-annular flow. Part 1: Experiments

Published online by Cambridge University Press:  10 January 2009

M. d'OLCE
Affiliation:
Universite Pierre et Marie Curie-Paris 6, Universite Paris-Sud, CNRS, F-91405, Lab FAST, Bat 502, Campus Universitaire, Orsay F-91405, France
J. MARTIN
Affiliation:
Universite Pierre et Marie Curie-Paris 6, Universite Paris-Sud, CNRS, F-91405, Lab FAST, Bat 502, Campus Universitaire, Orsay F-91405, France
N. RAKOTOMALALA
Affiliation:
Universite Pierre et Marie Curie-Paris 6, Universite Paris-Sud, CNRS, F-91405, Lab FAST, Bat 502, Campus Universitaire, Orsay F-91405, France
D. SALIN
Affiliation:
Universite Pierre et Marie Curie-Paris 6, Universite Paris-Sud, CNRS, F-91405, Lab FAST, Bat 502, Campus Universitaire, Orsay F-91405, France
L. TALON*
Affiliation:
Universite Pierre et Marie Curie-Paris 6, Universite Paris-Sud, CNRS, F-91405, Lab FAST, Bat 502, Campus Universitaire, Orsay F-91405, France
*
†Email address for correspondence: talon@fast.u-psud.fr
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the 'Save PDF' action button.

We address the issue of the convective or absolute nature of the instability of core-annular pipe flows, in experiments using two miscible fluids of equal density but different viscosities, the core fluid being much less viscous than the wall one. We use a concentric co-current injection of the two fluids. An axisymmetric parallel base state is obtained downstream the injector. The core radius RI and the Reynolds number Re of the so-obtained base state are varied independently due to the control of the flow rate of each fluid. However, a downstream destabilization of this base state was observed within the explored range of the two control parameters RI and Re. Moreover, the fixed location of this destabilization, observed for some particular parameters, suggests an absolute nature of the instability. We present a tentative delineation of the nature (convective or absolute) of the instability and discuss the accessible measurements to experimentally address this issue.

Information

Type
Papers
Copyright
Copyright © Cambridge University Press 2008