Bubble Movement in Downward-Inclined Pipes
Publication: Journal of Hydraulic Engineering
Volume 135, Issue 11
Abstract
An experimental investigation with large-scale model tests of bubbles moving upward and downward in downward-inclined pipes is presented. The shape, velocity, and drag coefficient of single nonspherical air bubbles in continuous air-water flows are discussed. The bubble height depends mainly on the approach flow water velocity and the pipe slope. For stagnant bubbles, the bubble height is determined depending on these two parameters. Equilibrium of the drag and buoyancy forces is applied on single air bubbles in downward-inclined pipes. In pipes with pipe slope ranging from 0.052–0.087, the bubble drag coefficient is independent of the bubble Reynolds number. However, the bubble drag coefficient depends on the pipe slope and the approach flow water velocity. Using the approach of the equilibrium of the main forces the volume of stagnant bubbles can be predicted.
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Acknowledgments
The writers sincerely thank Professor Hans-Erwin Minor, director of the VAW at ETH Zurich, and Carl Robert Kriewitz for their steady support for this work. This work was financially supported by Swisselectric research.
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Information & Authors
Information
Published In
Journal of Hydraulic Engineering
Volume 135 • Issue 11 • November 2009
Pages: 1012 - 1015
Copyright
© 2009 ASCE.
History
Received: Jul 31, 2008
Accepted: Apr 27, 2009
Published online: Apr 29, 2009
Published in print: Nov 2009
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