Haut PDF Influence d'une phase dispersée sur l'écoulement de Taylor-Couette

Influence d'une phase dispersée sur l'écoulement de Taylor-Couette

Influence d'une phase dispersée sur l'écoulement de Taylor-Couette

Les 15 èmes Journées Scientifiques de Marcoule 9 – 10 juin 2015 Document propriété du CEA – Reproduction et diffusion externes au CEA soumises à l’autorisation de l’émetteur INFLUENCE D’UNE PHASE DISPERSEE SUR L’ECOULEMENT DE TAYLOR-COUETTE

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Influence d'une phase dispersée sur le mélange dans l'écoulement de Taylor-Couette

Influence d'une phase dispersée sur le mélange dans l'écoulement de Taylor-Couette

1 Synthèse et Conclusions Cette étude avait pour but de caractériser l’influence d’une phase disper- sée sur le mélange en écoulement de Taylor-Couette. En effet, le mélange axial contrecarre le mécanisme de séparation dans la colonne Couette et doit donc être, sinon minimisé, du moins quantifié dans les colonnes d’ex- traction. fAfin de distinguer les différents mécanismes physiques à l’origine du mélange dans un tel système, nous avons choisi de travailler avec des billes sphériques calibrées de Polyméthacrylate de méthyle (PMMA), de diamètre 800 µm à 1,5 mm, en nombre suffisant pour atteindre des réten- tions jusqu’à 32% pour les propriétés hydrodynamiques, et 8% pour l’étude du mélange en colonne Couette. Ces particules sont mises en suspension dans une solution aqueuse de Thiocyanate de Potassium (KSCN) et de Di- méthylsulfoxyde (DMSO). Nous nous sommes particulièrement intéressés aux deux premières instabilités de l’écoulement de Taylor-Couette, à savoir les régimes de Taylor Vortex Flow (TVF) et Wavy Vortex Flow (WVF). Dans ces deux régimes, des études précédentes réalisées en monophasique ont mis en évidence un lien étroit entre les propriétés hydrodynamiques et l’efficacité du mélange. Par exemple, lorsque le nombre de Reynolds aug- mente, les mélanges intra-vortex (Desmet et al. (1996)) et inter-vortex (Ako- nur and Lueptow (2003)) sont accélérés. Lorsque le nombre de Reynolds dé- passe une valeur critique, un changement de régime (du TVF vers le WVF) apparaît. En régime ondulatoire (WVF), des études numériques par Rud- man (1998) et expérimentales par Nemri et al. (2014) s’accordent à préciser l’importance de la longueur d’onde axiale, représentant la taille d’une paire de vortex adjacents, sur le mélange. Enfin, le mélange intra-vortex et le mé- lange inter-vortex sont d’autant plus rapides que le nombre d’onde azimutal
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Étude expérimentale et numérique du mélange et de la dispersion axiale dans une colonne à effet Taylor-Couette

Étude expérimentale et numérique du mélange et de la dispersion axiale dans une colonne à effet Taylor-Couette

1 4 CHAPITRE 1. INTRODUCTION - CONTEXTE INDUSTRIEL 1.1 Le procédé PUREX Le procédé hydro-métallurgique « PUREX » (acronyme de Plutonium Uranium Refining by EXtraction), mis au point dès 1945 aux États-Unis, se base sur l’extraction liquide-liquide comme méthode de séparation. Il per- met de séparer les matières nobles (l’uranium et le plutonium) des produits de fission contenus dans le combustible usé des réacteurs à eau pressuri- sée (REP). Il est basé sur l’utilisation d’une molécule organique ayant des propriétés remarquables de sélectivité : le phosphate de tri-butyle (TBP) en solution dans un alcane (par exemple du TPH : tétrapropylène hydro- géné). Le transfert de matière s’effectue à la surface de contact entre les deux phases liquides non miscibles : la solution aqueuse contenant le com- bustible dissous et la phase organique contenant l’extractant. Cette surface de contact est maximisée en créant une émulsion, constituée de fines gout- telettes de phase discontinue (ou dispersée) dans la phase continue. Après transfert, les deux phases, l’une enrichie et l’autre appauvrie en éléments à récupérer, sont séparées par décantation et/ou par centrifugation.
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Numerical simulation of bubble dispersion in turbulent Taylor-Couette flow

Numerical simulation of bubble dispersion in turbulent Taylor-Couette flow

of Taylor Vortices and (right) on their radial component. Table V reports the two-phase flow configurations we simulated. We are aiming to study the influence of the Reynolds number (through H variation), the bubble size by changing R b /R 2 , and the role of buoyancy effects by considering two different values of C. In exper- iments, these effects can hardly be tested independently since C depends both on gravity and bubble size (bubble size is controlled by the injection flow rate, the nozzle geometry and possibly the local shear rate which in turn depends on the flow Reynolds number). For all configurations the dispersed phase is composed of one million bubbles, but figures representing bubble positions display only 20000 bubbles in order to ease visualizations (typically fig. 14). Table V also gives an estimate of the Stokes numbers based on the characteristics of the inner cylinder wall turbulent scales St = τ b /(δ 1 ∗ /u ∗ 1 ). Our analysis is organized as follows: we will first present the general arrangement of the dispersed phase and the corresponding void fraction profiles. We will focus on cases without gravity effects (g = 0). Then, we describe the effect of gravity by varying C and finally we discuss the effects of the flow Reynolds number Re and the bubble size R b /R 2 .
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Effect of bubble’s arrangement on the viscous torque in bubbly Taylor-Couette flow

Effect of bubble’s arrangement on the viscous torque in bubbly Taylor-Couette flow

The objective of this part is to study the e ffect of buoyancy (through varying the viscosity of the mixture and the bubble size), as well as the e ffect of the Reynolds number on the bubble arrangement in the gap. Unfortunately, it is not possible to test experimentally the influence of these variables separately. Indeed, for a given bubble size, C increases as H decreases, with the increasing of the Reynolds number. Table III reports the two-phase flow configurations, for which the Eulerian cartographies of the gas-phase are displayed. These flow conditions were selected because the gas Eulerian cartographies of each of them illustrated the various types of bubble arrangement observed in the framework of the present study. Cases 1 to 3 exhibit di fferent arrangements for same bubble size and same viscosity, when increasing the Reynolds number. Case 4 corresponds to same bubble size as the previous cases but with an increase of the Reynolds number and an increase of the rising velocity by changing the viscosity. Case 5 illustrates the influence of the bubble size for same Reynolds number and same viscosity. Case 6 corresponds to a condition of high Reynolds number and large bubbles, thus leading to large void fraction.
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Preferential accumulation of bubbles in Couette-Taylor flow patterns

Preferential accumulation of bubbles in Couette-Taylor flow patterns

共Received 12 December 2006; accepted 30 May 2007; published online 17 August 2007兲 We investigate the migration of bubbles in several flow patterns occurring within the gap between a rotating inner cylinder and a concentric fixed outer cylinder. The time-dependent evolution of the two-phase flow is predicted through three-dimensional Euler-Lagrange simulations. Lagrangian tracking of spherical bubbles is coupled with direct numerical simulation of the Navier-Stokes equations. We assume that bubbles do not influence the background flow 共one-way coupling simulations兲. The force balance on each bubble takes into account buoyancy, added-mass, viscous drag, and shear-induced lift forces. For increasing velocities of the rotating inner cylinder, the flow in the fluid gap evolves from the purely azimuthal steady Couette flow to Taylor toroidal vortices and eventually a wavy vortex flow. The migration of bubbles is highly dependent on the balance between buoyancy and centripetal forces 共mostly due to the centripetal pressure gradient兲 directed toward the inner cylinder and the vortex cores. Depending on the rotation rate of the inner cylinder, bubbles tend to accumulate alternatively along the inner wall, inside the core of Taylor vortices or at particular locations within the wavy vortices. A stability analysis of the fixed points associated with bubble trajectories provides a clear understanding of their migration and preferential accumulation. The location of the accumulation points is parameterized by two dimensionless parameters expressing the balance of buoyancy, centripetal attraction toward the inner rotating cylinder, and entrapment in Taylor vortices. A complete phase diagram summarizing the various regimes of bubble migration is built. Several experimental conditions considered by Djéridi, Gabillet, and Billard 关Phys. Fluids 16, 128 共2004兲兴 are reproduced; the numerical results reveal a very good agreement with the experiments. When the rotation rate is increased further, the numerical results indicate the formation of oscillating bubble strings, as observed experimentally by Djéridi et al. 关Exp. Fluids 26, 233 共1999兲兴. After a transient state, bubbles collect at the crests or troughs of the wavy vortices. An analysis of the flow characteristics clearly indicates that bubbles accumulate in the low-pressure regions of the flow field. © 2007 American Institute of Physics. 关DOI: 10.1063/1.2752839 兴
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Quantitative visualization of swirl and cloud bubbles in Taylor–Couette flow

Quantitative visualization of swirl and cloud bubbles in Taylor–Couette flow

Moreover, with increasing gravity effect (Chouippe et al. 2014 ) or gas injection flux (Shiomi et al. 1993 ), the bubble arrangement can shift from a toroïdal mode to a spiral mode. Jnteresting enough is that the maximum drag reduction is observed during the transition from the toroidal to the spiral regimes (Murai et al. 2008 ). Bubble distributions in a three-dimensional domain the consequence of two-way interaction between bubbles and liquid base flows, here TC flow. They have to be reflected by the influence of the drag reduction, and thus, knowing the time evolution of bubble distributions and velocity of accumulated bubbles is a key step towards understanding bubbly drag reduction processes. lndividual bubble motions in bubble flow have been investigated (e.g., Murai et al. 2000 ), and the differences of behaviors between isolated bubbles and bubbles belonging to organized groups have also been discussed (e.g., Cheng et al. 2005 ). Furthermore, there are some reports performing the measurements of bubble distributions in a three­ dimensional domain in bubbly conditions (e.g., Murai et al. 2001 ). However, general three-dimensional tracking for capturing bubble distributions is not applicable to the annular flow system in TC flow because of problems in optical configuration. Attempts to determine the local distribution in the radial-axial plane of bubbles and bubble velocity (Watamura et al. 2013 ; Ndongo Fokoua et al. 2015 ) based on individual bubble tracking techniques, however, cannot discriminate bubbles captured in the vortices (swirl bubbles, here after) from bubbles trapped in the outflow region near the inner cylinder (termed cloud bubbles, here after) in the triple capture mode (Fig. l a) using their size. In fact, clouds can be supeiposed with swirl bubbles, as shown in Fig. 2 a, which is a snapshot of bubble distributions in the triple capture mode. Moreover, the determination of azimuthal velocity of bubbles is crucial. Mehel et al. ( 2006 ) determined azimuthal velocity profiles of the gas phase in the vortex core by adopting intrusive dual fiber-optical probes, but this technique is not applicable in the near-wall region of the outflow, where bubbles are accumulated.
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Numerical simulation of bubble dispersion in turbulent Taylor-Couette flow

Numerical simulation of bubble dispersion in turbulent Taylor-Couette flow

We show here that depending on the bubble size, these structures can have a significant effect on bubble preferential accumulation in the vicinity of the wall. D. With gravity effects The effect of gravity is now discussed by considering the case C ≈ 0.5: the terminal rising velocity of the bubbles is almost half of the characteristic velocity of Taylor vortices. We remind that periodic boundary conditions are used for the bubble and the flow equations, so that bubbles reaching the upper boundary are re-injected at the bottom of the domain with the same velocity and acceleration. Compared to case C = ∞ (g = 0), we observe a different response of the bubbly phase. The influence of the outflow jet is less pronounced as shown in fig. 18 and fig. 19 for both bubble size (cases 4 and 5, respectively). Initial ejection by the outflow jet is now weaker, which confirms that Taylor vortices have less influence and that bubble migration in the vertical direction is dominated by buoyancy. In the radial direction, bubbles are attracted towards the inner cylinder, as expected. For larger bubbles, the spatial arrangement does not match herringbone-like streaks but forms well defined spirals as shown in fig. 20. These spirals could be related to bubbly spiral patterns observed experimentally 19 and reported in fig. 21. We estimated the value of
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Modélisation eulérienne de la phase dispersée dans les moteurs à propergol solide, avec prise en compte de la pression particulaire

Modélisation eulérienne de la phase dispersée dans les moteurs à propergol solide, avec prise en compte de la pression particulaire

masse avec la phase gazeuse sont donc nuls et le diamètre des particules reste constant. Cette modélisation, plus simple que celle de particules évaporantes, permet de simuler des écoulements diphasiques où les particules d’aluminium sont quasiment instantanément transformées en alumine. Concrètement, les simulations sont effectuées en injectant des particules dont le diamètre est directement celui des résidus de combustion obtenus pour la granulométrie physique étudiée. Ces particules ont donc les caractéristiques de l’alumine (densité, température, chaleur spécifique). Cette modélisation diphasique inerte est également employée lors d’investigation sur le rôle des particules dans certains mécanismes. Dans ce cas, les particules d’aluminium sont supposées inertes : elles ne vont pas réagir avec le milieu gazeux ambiant, ni s’évaporer. Ce type de simulations ne représente évidemment pas correctement la physique de l’écoulement mais permet, en décou- plant artificiellement les phénomènes, d’accéder à une meilleure compréhension des mécanismes liés aux écoulements diphasiques dans les propulseurs. Par exemple, nous pouvons ainsi estimer l’influence des particules sur l’écoulement gazeux en fonction de leur diamètre. Bien qu’imparfaite au niveau de la physique, cette méthode a permis d’aboutir à une description plausible du méca- nisme d’amplification des ODP par une phase dispersée inerte (cf. Chapitre 8).
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Evolution des propriétés morphologiques de flocs de latex en réacteur de Taylor-Couette

Evolution des propriétés morphologiques de flocs de latex en réacteur de Taylor-Couette

agrégats Les résultats obtenus dans ce chapitre sont issus d’expériences de floculation en réacteur de Taylor-Couette en hydrodynamique séquencée. Les conditions de l’écoulement demeurent inchangées. Les mêmes taux de cisaillement seront étudiés et le séquençage sera identique à celui développé dans le chapitre précédent. Nous étudierons ainsi l’influence des conditions hydrodynamiques durant les six étapes conduites alternativement à faible et fort taux de cisaillement sur les propriétés des agrégats de latex. Nous nous intéressons à présent à l’influence du choix du coagulant sur les propriétés de taille et de forme des agrégats. Trois coagulants ont été choisis: le chlorure de sodium, le sulfate d’aluminium et le polychlorure de diallyl diméthyl ammonium (PolyDADMAC). Dans les conditions de l’expérience, le mécanisme à l’œuvre lors de l’ajout de chlorure de sodium ou de sulfate d’aluminium comme nous l’avons vu au chapitre II est principalement la neutralisation de charges. Le polymère quant à lui induit un mécanisme de floculation par pontage. L’étude de ces trois coagulants, mettant en avant deux mécanismes fréquemments observés d’agrégation, va permettre de discuter de l’impact de la physico-chimie sur la taille et la structure de flocs de latex placés sous contraintes hydrodynamiques. Nous nous intéresserons dans un premier temps à l’impact des trois coagulants préalablement cités sur la taille des agrégats puis, dans un second temps, aux conséquences sur leur forme.
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Experimental investigation of mixing efficiency in particle laden Taylor-Couette flows

Experimental investigation of mixing efficiency in particle laden Taylor-Couette flows

4 Conclusion We have carried out an experimental characterization of tracer mixing in the Taylor-Couette flow configura- tion. More specifically, we have measured the enhance- ment of mixing efficiency by solid particles with various sizes and volume concentrations. Particles are neutrally buoyant and the size ratio of the particle diameter to the gap between cylinders ranges from 0.073 to 0.14. A specific attention has been paid to the Planar Laser- Induced Fluorescence (PLIF) measurements due to the presence of particles. Both density and refractive in- dexes of particles were matched to fluid properties. The presence of beads in the flow requires to use two PLIF channels and the unsteady deformation of the vortices for WVF is measured by PIV (allowing detection the vortex boundaries for the determination of intravortex mixing). Systematic analysis and error quantification of the successive steps of image processing have been thoroughly discussed. We have shown that the deter- mination of mixing times is robust over the range of physical parameters we investigated.
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Experimental study of bubble-drag interaction in a Taylor-Couette flow

Experimental study of bubble-drag interaction in a Taylor-Couette flow

The bubbles accumulation in the flow has a direct influence on the liquid flow structures. As was shown from PIV measurements, bubbles trapping inside the Taylor vortices can lead to a decrease of the velocities of the Taylor vortices, leading to a contribution of the coherent motion that is reduced in favour of an enhancement of the small scale turbulence of the liquid. Generally speaking, in a Taylor Couette flow, the outflow is the region of minimum wall shear stress, and the inflow corresponds to the region of maximum wall shear stress applied on the inner cylinder. Thus the observed preferential decrease in velocity of the outflow can be responsible for the increase in the viscous torque. This situation is observed when bubbles are trapped by the vortices near the outflow (case a) and expected to occur also for bubbles accumulated in the outflow (case d). Thus one could expect the opposite trend (ie bubbles localized near the inflow close to the inner cylinder) for a bubble induced reduction in the viscous torque, but this trend needs to be confirmed by experimental investigation of the liquid flow.
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Quantitative visualization of swirl and cloud bubbles in Taylor–Couette flow

Quantitative visualization of swirl and cloud bubbles in Taylor–Couette flow

Moreover, with increasing gravity effect (Chouippe et al. 2014 ) or gas injection flux (Shiomi et al. 1993 ), the bubble arrangement can shift from a toroidal mode to a spiral mode. Interesting enough is that the maximum drag reduction is observed during the transition from the toroidal to the spiral regimes (Murai et al. 2008 ). Bubble distributions in a three-dimensional domain the consequence of two-way interaction between bubbles and liquid base flows, here TC flow. They have to be reflected by influence of the drag reduction, and thus, knowing the time evolution of bubble distributions and velocity of accumulated bubbles is a key step towards understanding bubbly drag reduction processes. Individual bubble motions in bubble flow have been investigated (e.g.,Murai et al. 2000 ) and differences of behaviors between isolated bubbles and bubbles belonging to organized groups have also been discussed (e.g.,Cheng et al. 2005). Further, there are some reports performing measurements of bubble distributions in a three-dimensional domain in bubbly conditions (e.g.,Murai et al. 2001). But general three-dimensional tracking for capturing bubble distributions is not applicable to the annular flow system in TC flow because of problems in optical configuration. Attempts to determine the local distribution in the radial-axial plane of bubbles and bubble velocity (Watamura et al. 2013 ; Fokoua et al, 2015 ) based on individual bubble tracking techniques, however, cannot discriminate bubbles captured in the vortices (swirl bubbles, here after) from bubbles trapped in the outflow region near the inner cylinder (termed cloud bubbles, here after) in the triple capture mode ( Fig. 1a ) by using their size. In fact, clouds can be superposed with swirl bubbles as seen on Fig. 2a which is a snapshot of bubble distributions in the triple capture mode. Moreover, the determination of azimuthal velocity of bubbles is crucial. Mehel et al. (2006) determined azimuthal velocity profiles of the gas phase in the vortex core by adopting intrusive dual fiber-optical probes, but this technique is not applicable in the near wall region of the outflow, where bubbles are accumulated.
En savoir plus

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Experimental study of bubble-drag interaction in a Taylor-Couette flow

Experimental study of bubble-drag interaction in a Taylor-Couette flow

The bubbles accumulation in the flow has a direct influence on the liquid flow structures. As was shown from PIV measurements, bubbles trapping inside the Taylor vortices can lead to a decrease of the velocities of the Taylor vortices, leading to a contribution of the coherent motion that is reduced in favour of an enhancement of the small scale turbulence of the liquid. Generally speaking, in a Taylor Couette flow, the outflow is the region of minimum wall shear stress, and the inflow corresponds to the region of maximum wall shear stress applied on the inner cylinder. Thus the observed preferential decrease in velocity of the outflow can be responsible for the increase in the viscous torque. This situation is observed when bubbles are trapped by the vortices near the outflow (case a) and expected to occur also for bubbles accumulated in the outflow (case d). Thus one could expect the opposite trend (ie bubbles localized near the inflow close to the inner cylinder) for a bubble induced reduction in the viscous torque, but this trend needs to be confirmed by experimental investigation of the liquid flow.
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Experimental study of bubble-drag interaction in a Taylor-Couette flow

Experimental study of bubble-drag interaction in a Taylor-Couette flow

Figure 4 and 5 display the viscous torque measured in two-phase flow for the largest and smallest bubbles respectively. To test reproducibility of injection effect on the viscous drag, different dataset were obtained for the same time after the inner cylinder velocity had reached its steady state, at several days interval. For the largest bubbles, the viscous torque increases with the Reynolds number (up to 10% of relative increase for Re=3000). For the smallest bubbles, the relative modifications of the torque are less important. Nevertheless, even if the trends are not very obvious, they are reproducible. It can be observed an increase (+5%) in the torque for Re≥14000 (ie: Ta≥4400) and a weak decrease (-2%) for Re≤6000 (ie: Ta≤1900), out of the range of systematic errors.
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Experimental investigation of mixing efficiency in particle‑laden Taylor–Couette flows

Experimental investigation of mixing efficiency in particle‑laden Taylor–Couette flows

of the 26 possible stable configurations observed when the two cylinders are allowed to rotate. When the outer cylin- der is at rest, only five regimes are commonly observed for single-phase flows. The Couette regime, which is the first regime that appears at low Reynolds, is laminar and steady (its velocity profile is provided in standard textbooks). The fluid flow has a single velocity component along the azi- muthal direction, and depends only on the radial distance r from the axis of rotation. When the rotation rate increases, Taylor Vortex Flow regime (TVF) appears. It results from a centrifugal instability that leads to the formation of toroidal vortices in the flow direction. These vortices are perpendicu- lar to the axis of rotation and are organized by pair (contra- rotative vortices). The flow in TVF regime is still axisym- metric and steady. For a given Reynolds number Re, the flow configuration is characterized by its axial wavelength,
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Experimental study of enhanced mixing induced by particles in Taylor–Couette flows

Experimental study of enhanced mixing induced by particles in Taylor–Couette flows

from the regions of high to low particle concentration. Because the spatial particle distribution is close to uni- form in our experiments, the mixing behavior can hardly be attributed to the gradient diffusion, proving that the main mechanism of interest in our case is more likely the shear-induced self-diffusion, illustrated in Fig. 8 . Similarly to heat transfer, the tracer dispersion efficiency is expected to grow linearly with the particle concentration for dilute suspensions because of the shear-induced particle agi- tation (see Fig. 8 ). This is in good agreement with our results about the intra-vortex mixing in TVF. However the inter-vortex efficiency in TVF does not show a linear evolution as a function of the particle volume fraction, due to two combined mecha- nisms. On one hand, shear-induced particle agitation occurs. On the other hand, the particles interact with the vortices outer layers, that are surrounding the cores, where poor mix- ing is observed. Experimentally, the characteristic thickness of those layers is estimated to 850 mm in single-phase flow. When the particles are moving in this zone where the convection is important, they drag dye while breaking the closed stream- lines between adjacent vortices (as evidenced in Fig. 9 ), leading to a non-monotonous enhancement of the inter-vortex mix- ing with increasing particle size. Small particles do not affect mixing while bigger ones (d = 1 mm, d = 1 .5 mm) are observed to increase mixing efficiency.
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Experimental study of enhanced mixing induced by particles in Taylor–Couette flows

Experimental study of enhanced mixing induced by particles in Taylor–Couette flows

A new setup based on 2-way PLIF measurements, coupled with PIV, was then proposed for the two-phase experiments. Two fluorescent dyes are simultaneously monitored ( Bouche et al., 2013 ). The first one, Rhodamine WT, is the real PLIF tracer from which the mixing properties of the flow will be investi- gated. The second one, Fluorescein, is uniformly diluted in the flow and used as a reference. Indeed, measured variations of fluorescein concentration are only due to the presence of parti- cles, making them easier to detect. Thanks to this second PLIF system, dynamic masks of the instantaneous particles surface are created. These masks are achieved by an image processing based on a combination of a threshold and a Watershed seg- mentation, and are used to correct the PLIF rhodamine raw images, aiming at a better mixing quantification.
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Experimental investigation of mixing and axial dispersion in Taylor–Couette flow patterns

Experimental investigation of mixing and axial dispersion in Taylor–Couette flow patterns

square grid (16  16) with sub-pixel intercorrelation. The uncertainty on the Reynolds number due to the variation in the inner cylinder speed, fluid viscosity, and other factors was at most 5 %. The uncertainty on the velocity measurements depends on several factors (peak locking, correlation technique and interpolation scheme, density mismatch between tracer particles and fluid). We have chosen to use hollow glass particles, because density matching of those particles with our solution is very good. The other sources of error have been controlled based on PIV state of the art. As a validation test, PIV measurements of the pure azimuthal Couette flow were performed to check accuracy (in a radial plane, the velocity should be zero). The maximum of spurious velocities we measured was of the order of 1 % of the inner cylinder speed
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Analysis of the flow pattern modifications in a bubbly Couette-Taylor flow

Analysis of the flow pattern modifications in a bubbly Couette-Taylor flow

Handle ID: . http://hdl.handle.net/10985/10301 To cite this version : Amine MEHEL, Céline GABILLET, Henda DJERIDI - Analysis of the flow pattern modifications in a bubbly Couette-Taylor flow - Physics of Fluids - Vol. 19, p.118101-1: 118101-4 - 2007

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