Experimental study of the effect of a wavy surface in Taylor-Couette-Poiseuille flow
Résumé
In this article, we study the effect of an imposed axial flow on the Taylor-Couette flow with regularly
distributed wavy form on the surface of the inner cylinder.
Without an imposed axial flow, a series of clearly distinguishable flow regimes develops; from the
laminar flow Couette Flow CF to the vortex flow Wavy Taylor WVF, to the modulated flow Wavy
Taylor Vortex MWVF and chaotic flows up to a full turbulence. Their appearance is highly dependent
on the geometry of the CT system.
Furthermore, when an axial flow is imposed on a Taylor-Couette flow, new helical vortex structures are
observed. The emergence of these flow states indicates that a richer dynamic can develop in CT flows.
Hence, an imposed axial flow is an important factor / parameter in CT flow applications.
The superimposition of an axial flow can accentuate the dependence of the effect on surface roughness
(form of the inner cylinder). It is interesting to note that the presence of a rough surface on the inner
cylinder of the CTS accelerates the appearance of helical structures.
Using the visualization by Kalliroscope and the polarography technique, the time series of the velocity
gradient obtained, were associated with each flow state, thus allowing the analysis and identification of
the effect of an imposed axial flow on hydrodynamic instabilities’ Couette-Taylor flow