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Structure of two-phase air-water flows. Study of average void fraction and flow patterns; Structure des ecoulements diphasiques eau-air. Etude de la fraction de vide moyenne et des configurations d'ecoulement

Abstract

This report deals with experimental work on a two phase air-water mixture in vertical tubes of different diameters. The average void fraction was measured in a 2 metre long test section by means of quick-closing valves. Using resistive probes and photographic techniques, we have determined the flow patterns and developed diagrams to indicate the boundaries between the various patterns: independent bubbles, agglomerated bubbles, slugs, semi-annular, annular. In the case of bubble flow and slug flow, it is shown that the relationship between the average void fraction and the superficial velocities of the phases is given by: V{sub sg} = f(<{alpha}>) * g(V{sub sl}). The function g(V{sub sl}) for the case of independent bubbles has been found to be: g(V{sub sl}) = V{sub sl} + 20. For semi-annular and annular flow conditions; it appears that the average void fraction depends, to a first approximation only on the ratio V{sub sg}/V{sub sl}. (author) [French] Ce rapport est une etude experimentale d'un melange diphasique eau-air dans des tubes verticaux de differents diametres. Nous avons mesure la fraction de vide moyenne dans une portion de canal de longueur 2 m, au moyen d'un systeme de vannes a fermeture rapide et simultanee. Au moyen de  More>>
Authors:
Roumy, R [1] 
  1. Commissariat a l'Energie Atomique, Grenoble (France). Centre d'Etudes Nucleaires
Publication Date:
Jul 01, 1969
Product Type:
Technical Report
Report Number:
CEA-R-3892
Resource Relation:
Other Information: 9 refs; PBD: 1969
Subject:
42 ENGINEERING; BENCH-SCALE EXPERIMENTS; BUBBLES; EXPERIMENTAL DATA; FLOW VISUALIZATION; TWO-PHASE FLOW; VELOCITY; VOID FRACTION
OSTI ID:
20552725
Research Organizations:
CEA Grenoble, 38 (France)
Country of Origin:
France
Language:
French
Other Identifying Numbers:
TRN: FR04R3892007982
Availability:
Available from INIS in electronic form
Submitting Site:
FRN
Size:
65 pages
Announcement Date:

Citation Formats

Roumy, R. Structure of two-phase air-water flows. Study of average void fraction and flow patterns; Structure des ecoulements diphasiques eau-air. Etude de la fraction de vide moyenne et des configurations d'ecoulement. France: N. p., 1969. Web.
Roumy, R. Structure of two-phase air-water flows. Study of average void fraction and flow patterns; Structure des ecoulements diphasiques eau-air. Etude de la fraction de vide moyenne et des configurations d'ecoulement. France.
Roumy, R. 1969. "Structure of two-phase air-water flows. Study of average void fraction and flow patterns; Structure des ecoulements diphasiques eau-air. Etude de la fraction de vide moyenne et des configurations d'ecoulement." France.
@misc{etde_20552725,
title = {Structure of two-phase air-water flows. Study of average void fraction and flow patterns; Structure des ecoulements diphasiques eau-air. Etude de la fraction de vide moyenne et des configurations d'ecoulement}
author = {Roumy, R}
abstractNote = {This report deals with experimental work on a two phase air-water mixture in vertical tubes of different diameters. The average void fraction was measured in a 2 metre long test section by means of quick-closing valves. Using resistive probes and photographic techniques, we have determined the flow patterns and developed diagrams to indicate the boundaries between the various patterns: independent bubbles, agglomerated bubbles, slugs, semi-annular, annular. In the case of bubble flow and slug flow, it is shown that the relationship between the average void fraction and the superficial velocities of the phases is given by: V{sub sg} = f(<{alpha}>) * g(V{sub sl}). The function g(V{sub sl}) for the case of independent bubbles has been found to be: g(V{sub sl}) = V{sub sl} + 20. For semi-annular and annular flow conditions; it appears that the average void fraction depends, to a first approximation only on the ratio V{sub sg}/V{sub sl}. (author) [French] Ce rapport est une etude experimentale d'un melange diphasique eau-air dans des tubes verticaux de differents diametres. Nous avons mesure la fraction de vide moyenne dans une portion de canal de longueur 2 m, au moyen d'un systeme de vannes a fermeture rapide et simultanee. Au moyen de sondes resistives et de photographies nous avons determine la configuration de l'ecoulement et trace des cartes donnant les frontieres entre les differentes configurations d'ecoulement: bulles independantes, bulles agglomerees, bouchons, semi-annulaire, annulaire. Nous montrons que pour les regimes a bulles et a bouchons, une equation de la forme V{sub sg} = f(<{alpha}>) * g(V{sub sl}) relie la fraction de vide moyenne aux vitesses superficielles de chacune des phases. Nous avons pu determiner la fonction g(V{sub sl}) dans le cas du regime a bulles independantes, et nous trouvons g(V{sub sl}) = V{sub sl} + 20. Pour les regimes semi-annulaire et annulaire, il semble qu'en premiere approximation, la fraction de vide moyenne ne depende que du rapport V{sub sg}/V{sub sl}. (auteur)}
place = {France}
year = {1969}
month = {Jul}
}