Modal switching of bubbly Taylor–Couette flow investigated by particle tracking velocimetry

Murai, Yuichi; Tasaka, Yuji; Oishi, Yoshihiko; Takeda, Yasushi

doi:10.1007/s00348-018-2620-2

Cited by 12 publications

(16 citation statements)

References 41 publications

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“…In general, it relates centrifugal to the viscous forces, meaning that growing values correspond to higher levels of turbulence. Different definitions for Ta exist in literature and an overview of common definitions is given in Table 1 12,14,29,[31][32][33][34][35][36][37][38] . For the sake of brevity, in this work the definition in equation 1is based on the definition given by Lueptow et al 35,39 and Richter et al 35 The flow regimes in the annular gap vary with ω and can be characterized in terms of turbulence and the type and shape of the forming vortices.…”

Section: Fundamentals Of Taylor-couette Flowmentioning

confidence: 99%

“…The dispersion defining characteristics have been addressed recently by a number of groups leading to equations (32), (34), (37), and (38) for the determination of d 32 for various conditions [83][84][85][86] . For this purpose, different biphasic systems were investigated.…”

Section: Mass Transfer and Multiphase Mixingmentioning

confidence: 99%

“…The parameters C 1 to C 6 are available for two different columns of 0.1 m and 0.3 m in diameter and varying hydraulic load 70,86 . It has to be noted that the equations (37) and (39) are based on correlations for the rotating disc contactor modified for the application on the TCDC and not the TCR. (39) The specific power input for the TCR can be calculated following equation 40 42to numerically determine the power input of a lobed TCR 64,67 .…”

Section: Mass Transfer and Multiphase Mixingmentioning

confidence: 99%

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Taylor‐Couette reactor: Principles, design, and applications

et al. 2021

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The Taylor-Couette reactor (TCR) is an apparatus that capitalizes on the Taylor-Couette flow, which allows many flow regimes and conditions to perform (bio-)chemical conversions with precise control of various reactor characteristics. With the possibility to continuously perfuse the reactor with a reaction medium, the TCR becomes interesting for chemical engineering applications. In this review we introduce this reactor type and provide an overview of its history, principles of the flow regimes, and a description and design aspects of the reactors and their elements. Available information in the literature is summarized and harmonized to present available formulas and correlations in a consistent set of variables. Additionally, a wide number of applications in process technology is covered, including reactions in homogeneous, photo and enzymatic catalysis, polymer synthesis, and crystallization and aggregation-flocculation processes. Focusing on this reactor configuration, this article intends to be used as a hub for scientific groups interested in TCRs. This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process which may lead to differences between this version and the Version of Record. Please cite this article as

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Section: Fundamentals Of Taylor-couette Flowmentioning

confidence: 99%

Section: Mass Transfer and Multiphase Mixingmentioning

confidence: 99%

Section: Mass Transfer and Multiphase Mixingmentioning

confidence: 99%

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Taylor‐Couette reactor: Principles, design, and applications

et al. 2021

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“…Thickness of the laser sheet is about 2 mm in Gaussian effective value, which was judged optimum as the flow has significant out-of-plane velocity. The technique applied is the same as for Taylor-Couette flow (Murai et al, 2018). As water flow tracer for the visualizations, high porous-type particles (DIAION, HP20.…”

Section: Experimental Facilitymentioning

confidence: 99%

Quantitative visualization of vortex ring structure during wall impingement subject to background rotation

Oishi

Murai

Tasaka

2019

J Vis

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A single vortex ring subject to background rotation in the process of wall-impingement has been experimentally investigated by particle tracking velocimetry (PTV). Two parameter conditions of Reynolds and Rossby number were chosen in addition to stationary environment as much strong and competitive Coriolis force emerges in comparison with inertia induced by vortex rings. From horizontal PTV windows set on the rotating experimental frame above the bottom wall, comprehensive influences of Coriolis force on the wall-impinging reaction are visualized as space-time three-dimensional vorticity distributions. Against natural growth of azimuthal waves due to Widnall instability, wall-impinging suppresses the waves and rather reorganizes original primary vortex because of cyclonic swirl coherently induced during impingement. This resists to turbulent collapse of vortex ring during the impingement, and self-boosts own life time. We try to explain the mechanism of such an anti-decaying process in the final part, untangling the phenomenon with best read from the space-time correlations among three vorticity components.

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“…At small air injection rate, bubbles patterns still exhibit a toroidal arrangement [9]. But at higher air injection rates, different bubbles patterns such as toroidal or spiral patterns or the combination of these two patterns (i.e., composite flow) have been observed according to the Reynolds number and the air injection rate [8,13,14]. Yoshida et al [13] showed an example of the space-time diagram in the axial direction of the bubbles patterns for the composite flow where the space-time sequences of toroidal and spiral patterns are visible (see Fig.…”

Section: Introductionmentioning

confidence: 99%

Defect-mediated turbulence in bubbly Taylor-Couette flow

et al. 2020

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We investigate experimentally the defect-mediated turbulence (DMT) which is induced by bubbles injection in a Taylor-Couette flow when the inner cylinder is rotating while the outer cylinder is fixed. Bubbles of 1.2 mm in diameter are injected at the bottom of a Taylor-Couette device of radii ratio equal to 0.91. The tangential Reynolds number range is [2 200, 19 300] and the air injection rate varies up to 800 ml/min. For these conditions of the experiments, bubbles are trapped in the gap by the Taylor vortices and arranged as patterns (toroidal, wavy toroidal, spirals, and wavy spirals). Visualizations of the bubble patterns were carried out. When decreasing the Reynolds number or increasing the air injection rate, spiral and toroidal patterns can coexist in a composite flow. Defects occur in the bubble's patterns (merging or splitting of the Taylor vortex pairs). By analyzing the space-time diagram of bubbles patterns and their complex demodulation, we highlight different regimes and transitions in the DMT of the bubbly Taylor-Couette flow. The control parameter of the transitions is the air volumetric fraction, which evolves as the ratio between the axial injection Reynolds number and the tangential Reynolds number. By increasing the air volumetric fraction, the defects in the DMT flows are classified as three flow regimes: (i) structured composite flow where the defects are periodic in space and time, (ii) intermittency defects chaos where the defects zones alternate randomly with the patterns in time and space, and (iii) developed defects chaos with a large defects density. The statistical properties of these three regimes of the DMT are analyzed in the framework of the complex Ginzburg-Landau equation.

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Modal switching of bubbly Taylor–Couette flow investigated by particle tracking velocimetry

Cited by 12 publications

References 41 publications

Taylor‐Couette reactor: Principles, design, and applications

Taylor‐Couette reactor: Principles, design, and applications

Quantitative visualization of vortex ring structure during wall impingement subject to background rotation

Defect-mediated turbulence in bubbly Taylor-Couette flow

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