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Title: Void fraction, bubble velocity and bubble size in two-phase flow

Journal Article · · Int. J. Multiphase Flow; (United States)

Experiments were performed in atmospheric vertical air-water flows, for void fractions between 0.25 and 0.75 (cross-sectional averages) and superficial liquid velocities of 1.3, 1.7 and 2.1 m/s. Local values of void fraction and bubble velocity as well as the bubble diameter were measure by means of a resistivity probe technique. Reliable values were obtained for the local void fraction over the entire range 0 less than or equal to less than or equal to 1. The void fraction profiles appeared to have a local maximum at the pipe center, local maxima close to the wall were obviously absent. The resistivity probes are shown to measure the velocity of the interface between the conducting and nonconducting phases, which equal the gas velocity only for low void fractions. The measured data for void fraction and bubble velocity were correlated by means of power law distribution functions, with exponents given by a function o the cross-sectionally averaged void fraction. The Sauter mean diameters for the bubble size spectr found, agree reasonably well with diameters predicted by a theoretical model based on the energy dissipation in the flow.

Research Organization:
Laboratory for Thermal Power Engineering, Delft University of Technology, Delft
OSTI ID:
6192507
Journal Information:
Int. J. Multiphase Flow; (United States), Vol. 11:3
Country of Publication:
United States
Language:
English