Title

Experiments and modeling in bubbly flows at elevated pressures

Authors

Authors

R. Kumar; T. A. Trabold;C. C. Maneri

Comments

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Abbreviated Journal Title

J. Fluids Eng.-Trans. ASME

Keywords

ANNULAR 2-PHASE FLOW; PREDICTION; FRACTION; CHANNEL; DROPLET; SPHERE; LIFT; Engineering, Mechanical

Abstract

Measurements of local void fraction, rise velocity, and bubble diameter have been obtained for cocurrent, wall-heated, upward bubbly flows in a pressurized refrigerant. The instrumentation used are the gamma densitometer and the hot-film anemometer Departure bubble size is correlated in terms of liquid subcooling and bulk bubble size in terms of void fraction. Flow visualization techniques have also been used to understand the two-phase flow structure and the behavior of the bubbly flow for different bubble shapes and sizes, and to obtain the bubble diameter and rise velocity. The lift model is provided explicitly in terms of Eotvos number which is changed by changing the system pressure. In general, Eotvos number plays a strong role in determining both bubbly lift and drag. Such insight coupled with quantitative local and averaged data on void fraction and bubble size at different pressures has aided in developing bubbly flow models applicable to heated two-phase flows at high pressure.

Journal Title

Journal of Fluids Engineering-Transactions of the Asme

Volume

125

Issue/Number

3

Publication Date

1-1-2003

Document Type

Article

Language

English

First Page

469

Last Page

478

WOS Identifier

WOS:000183646900008

ISSN

0098-2202

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