Effects of Turbulence and Containing Wall on Rise Velocities of Single Bubbles in a Vertical Circular Pipe

Conference · Mon Jul 01 04:00:00 EDT 2002

OSTI ID:21072837

Okawa, Tomio; Torimoto, Kazuhiro; Nishiura, Masanori; Kataoka, Isao ^[1]; Mori, Michitsugu ^[2]

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1. Osaka University, 1-1, Yamadaoka, Suita-shi, Osaka, 5650871 (Japan)
2. Tokyo Electric Power Company, Incorporated, 1-3, Uchisaiwai-cho 1-chome, Chiyoda-ku, Tokyo, 1008560 (Japan)

Experiments were conducted to clarify the single bubble rise characteristics in turbulent flows in vertical flow channels. It was revealed that the rise velocity of a bubble relative to the time-averaged local liquid velocity could be much smaller in turbulent up-flows than in stagnant liquids. The reduction of relative velocity was estimated to be caused by the two factors: turbulence in continuous phase and steep velocity gradient near wall; new correlations for describing these two effects were proposed. The relative velocity between the phases significantly affects the lateral phase distribution in multidimensional simulation of bubbly two-phase flow and the present correlations can give reasonable predictions for the relative velocity in turbulent flow. It is hence expected that the new correlations can contribute to the further improvement of the simulation models of bubbly two-phase flows. (authors)

• Research Organization: The ASME Foundation, Inc., Three Park Avenue, New York, NY 10016-5990 (United States)
• OSTI ID: 21072837
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
BUBBLES
CORRELATIONS
DISTRIBUTION
FORECASTING
LIQUIDS
SIMULATION
TURBULENCE
TURBULENT FLOW
TWO-PHASE FLOW
VELOCITY
WALLS