Material Information |
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Title: |
13.1.1 - Experimental Investigation and Physical Modeling of a Two-Phase Bubbly Flow in Horizontal Pipe Fluidized and Circulating Fluidized Beds |
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Series Title: |
7th International Conference on Multiphase Flow - ICMF 2010 Proceedings |
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Physical Description: |
Conference Papers |
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Creator: |
Marchand, M. Bottin, M. Berlandis, J.-P. Serre, G. Hervieu, E. |
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Publisher: |
International Conference on Multiphase Flow (ICMF) |
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Publication Date: |
June 4, 2010 |
Subjects |
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Subject: |
horizontal pipe bubbly two-phase flow experiment physical modeling |
Notes |
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Abstract: |
The METERO experiment is designed by the French Atomic Energy Commission to provide exhaustive database for
horizontal two-phase flow in adiabatic conditions and validate MCFD codes as well as to characterize the opponent
hydrodynamic mechanisms responsible for horizontal water-air flow stratification. The test section is a 5 meter long Plexiglas
pipe, 0.1 meter in diameter, equipped with various measurement techniques, including hot film anemometry, home made
optical probes and fast video cameras. Different flow regimes are generated by varying the water superficial velocity from 0
to 5.3 m/s and the gas superficial velocity from 0 to 0.127 m/s.
The single-phase liquid flow agreement with literature on pipe flows has been checked by hot film velocimetry and several
two-phase flow conditions have been investigated for 3 axial locations and various values of the liquid and gas superficial
velocities by means of fast camera video. Flow pattern maps have been plotted, according to the description of Govier & Aziz
(1972) and the intermittent regime has been studied accurately. A new transition line between buoyant bubble and stratified
bubble regimes has then been proposed.
The features of the METERO two-phase flow revealed by videos have been also highlighted by hot film measurements
carried out for the same 3 axial location, a high value of the liquid velocity (4.42 m/s) and various values of the gas
superficial velocity, ranging from 0 (single phase) to 0.127 m/s.
The gas influence, slight for JG< 0.06 m/s and strongly increasing beyond this value, is demonstrated by a growing bubble
layer in the upper region of the pipe when the gas flow rate rises. The effect of this bubble layer is to slow down the main
liquid flow and enhance turbulence in this region, as can be seen on the mean and turbulent velocity as well as kinetic energy
radial profiles. These observations are in good agreement with the one depicted for similar conditions by Iskandrani &
Kojasoy (2001) or Ekambara et al. (2008). Moreover, the linear behavior of the averaged kinetic energy versus the axial
location suggests that bubbly induced turbulence is injected at the inlet of the test section and then transported by the main
liquid flow towards the exit.
These trends are attested by optical probe measurements carried out for the same conditions. The bubble layer generates
increased void fraction in the upper region and when the gas injection is raised, the void fraction profiles are enhanced
whatever the radial location. Supplementary data points, acquired for JL=5.3 m/s, show that the two-phase flow regime gets
more dispersed and the void fraction profiles tend to flatten when the liquid flow rate is increased. All these observations are
in good agreement with the literature cited previously. The interface area concentration profiles follow the same trends
accounting more likely for bubble sedimentation than for coalescence. Finally, plots of the averaged interface area
concentration exhibit a linear growth versus JG, already observed by authors in vertical pipe configuration, with almost the
same slope for all the X locations as soon as the water flow is fully developed (20D). Finally, a new correlation is proposed
for the behavior of <Ai> vs. JG. |
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General Note: |
The International Conference on Multiphase Flow (ICMF) first was held in Tsukuba, Japan in 1991 and the second ICMF took place in Kyoto, Japan in 1995. During this conference, it was decided to establish an International Governing Board which oversees the major aspects of the conference and makes decisions about future conference locations. Due to the great importance of the field, it was furthermore decided to hold the conference every three years successively in Asia including Australia, Europe including Africa, Russia and the Near East and America. Hence, ICMF 1998 was held in Lyon, France, ICMF 2001 in New Orleans, USA, ICMF 2004 in Yokohama, Japan, and ICMF 2007 in Leipzig, Germany. ICMF-2010 is devoted to all aspects of Multiphase Flow. Researchers from all over the world gathered in order to introduce their recent advances in the field and thereby promote the exchange of new ideas, results and techniques. The conference is a key event in Multiphase Flow and supports the advancement of science in this very important field. The major research topics relevant for the conference are as follows: Bio-Fluid Dynamics; Boiling; Bubbly Flows; Cavitation; Colloidal and Suspension Dynamics; Collision, Agglomeration and Breakup; Computational Techniques for Multiphase Flows; Droplet Flows; Environmental and Geophysical Flows; Experimental Methods for Multiphase Flows; Fluidized and Circulating Fluidized Beds; Fluid Structure Interactions; Granular Media; Industrial Applications; Instabilities; Interfacial Flows; Micro and Nano-Scale Multiphase Flows; Microgravity in Two-Phase Flow; Multiphase Flows with Heat and Mass Transfer; Non-Newtonian Multiphase Flows; Particle-Laden Flows; Particle, Bubble and Drop Dynamics; Reactive Multiphase Flows |
Record Information |
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Bibliographic ID: |
UF00102023 |
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Volume ID: |
VID00316 |
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Source Institution: |
University of Florida |
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Holding Location: |
University of Florida |
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Rights Management: |
All rights reserved by the source institution and holding location. |
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Resource Identifier: |
1311-Marchand-ICMF2010.pdf |
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