Topical Problems of Fluid Mechanics


Institute of Thermomechanics AS CR, v.v.i.	CTU in Prague Faculty of Mech. Engineering Dept. Tech. Mathematics	MIO Université du Sud Toulon Var - AMU - CNRS - IRD	Czech Pilot centre ERCOFTAC

Experimental Investigation of the Free Surface Effect on the Conical Taylor -Couette Flow System
Yahi F., Hamnoune Y., Lecheheb S., Bouabdallah A.
Abstract:
The aim of this work is to highlight the critical thresholds corresponding to the onset of different instabilities considered in the flow between two vertical coaxial cones with and without free surface. The inner cone is rotating and the outer one is maintained at rest. Both cones have the same apex angle ? = 12 giving a constant annular gap ? = d/R1max. The height of the fluid column is H = 155mm and can be progressively decreased for each studied case of the flow system. Two kinds of configuration are studied, small and large gap configurations The working fluid is assumed as Newtonian and having constant properties as density and viscosity within the range of the required experimental conditions. By means of visualization technique of the flow we were able to show the different transition modes occurring in the conical flow system according to the aspect ratio and then the induced action of the free surface which introduces a delay in the onset of different instability modes. The obtained results in term of features and stability of the flow are compared to those of M. Wimmer [3-8] and N Noui-Mehidi [9].
Keywords:
conical Taylor-Couette flow, free surface effect, transition

Fulltext: PDF DOI:

In Proceedings Topical Problems of Fluid Mechanics 2015, Prague, 2015 Edited by David Šimurda and Tomáš Bodnár, pp. 273-280 ISBN 978-80-87012-55-0 (Print) ISSN 2336-5781 (Print)