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

Immiscible Fluids in Cylindrical Taylor Couette System
N. Merabet, A. Mahamdia, F. Mokhtari, M. Mahloul
Abstract:
In the present work, we investigate experimentally the development of hydrodynamic instability phenomena of immiscible liquids flow with free surface between concentric cylinders when the outer cylinder is fixed and the inner one rotates. The combined effect of the free surface and the aspect ratio is studied for a single fluid flow and for two fluids flow. The onset of the Taylor vortex (Tc1) is not affected for both studied cases. Its value remains unchanged Tc1 = 41. The critical speed for the appearance of the wave instability Tc2 of the heavy fluid flow is found to be very sensitive to the presence of the free surface. Increasing the aspect ratio delays the appearance of this instability. However, the effect of the free surface is removed for large aspect ratios and the flow becomes stable. When the gap is partially filled with two immiscible fluids the variation of aspect ratio of light fluid ΓHF and heavy fluid ΓLF can stabilize or destabilize the appearance of the wave instability.
Keywords:
Instability , Immiscible fluids, Free surface , Taylor Couette

Fulltext: PDF DOI: https://doi.org/10.14311/TPFM.2019.022

In Proceedings Topical Problems of Fluid Mechanics 2019, Prague, 2019 Edited by David Šimurda and Tomáš Bodnár, pp. 161-168 ISBN 978-80-87012-69-7 (Print) ISSN 2336-5781 (Print)