Characterization of Taylor vortex flow in a short liquid column

Abstract

in Wiley InterScience (www.interscience.wiley.com).We present a study on Taylor vortex flow in the annulus between a rotating inner cylinder and a stationary outer cylinder, featured with a wide gap (radius ratio is 0.613) and a short column (aspect ratio is 5.17). A particle image velocimetry (PIV) system was used to determine the position, shape, and velocity distribution of the vortices, by which the flow was also confirmed to lie in the nonwavy Taylor vortex regime for all operating conditions explored in this study. Our results suggest that end boundary effects are important, in which the vortex number decreases with decreasing column length. For a system with an aspect ratio of 5.17, six vortices appear in the gap with their position, size, and shape varying at different Reynolds numbers. The fluid velocities show an asymmetric feature with respect to the vortex centers, while the maximum axial and radial velocities increase almost linearly with the increasing reduced Reynolds number (Re À Re c ). In addition, computational fluid dynamics study was employed under the same conditions, and its results agree well with the PIV measurements. Overall, this study provides a quantitative understanding of the formation of Taylor vortices in a constrained space. V V C 2009 American Institute of Chemical Engineers AIChE J, 55: 3056-3065, 2009

PIV Study of the Flow Across the Meridional Plane of Rotating Cylinders with Wide Gap

“…The difference in the magnitude between the axial velocity near the wall of the inner cylinder and that near the wall of the outer cylinder is observed to be small, indicating that there is a balance in the net axial flow along both walls. Figure 7 displays the normalised radial velocity profile at = + 0.5 , which has been the radial coordinate of choice for most of the radial velocity profiles reported in the open literature, such as the ones reported in [26]- [27]. The profile exhibits a periodic trend along the axial direction that is consistent with the one reported in previous work [26]- [27].…”

“…Figure 7 displays the normalised radial velocity profile at = + 0.5 , which has been the radial coordinate of choice for most of the radial velocity profiles reported in the open literature, such as the ones reported in [26]- [27]. The profile exhibits a periodic trend along the axial direction that is consistent with the one reported in previous work [26]- [27]. Approximately four cycles of a periodic oscillation along / are shown in figure 7.…”

“…The velocity profile along the gap mid-span of the annulus has been a focus of interest in most of the previous studies on the Taylor vortex flow including [26] and [27]. To the best of the authors' knowledge, no previous study has reported the velocity distribution at radial positions near the wall of the inner cylinder and near the wall of the outer cylinder.…”

Spatial resolution and dissipation rate estimation in Taylor--Couette flow for tomographic PIV

“…They applied a glass box, filled with a liquid that matches the refractive index of the working fluid, that encloses the Taylor-Couette flow system in order to avoid effects due to refraction from the curved outer cylinder wall. Since then, 2D PIV has been used to examine different flow characteristics of Taylor-Couette flows (Akonur and Lueptow 2003;Wang et al 2005;Smieszek and Egbers 2005;Racina and Kind 2006;Abcha et al 2008;Deng et al 2009). Akonur and Lueptow (2003) performed planar PIV in radial-azimuthal planes in a setup very similar to the one of Wereley and Lueptow (1998).…”

On the Onset of Taylor Vortices in Finite-Length Cavity Subject to a Radial Oscillation Motion

“…Recently, Deng et al, (2009) presented an experimental and numerical study on the onset of Taylor vortices in short cylinders with an aspect ratio of 5.17. They found that the vortex number decreases with decreasing fluid column length.…”