Numerical Calculation of Turbulence Structure in Depth-Varying Unsteady Open-Channel Flows
Publication: Journal of Hydraulic Engineering
Volume 132, Issue 7
Abstract
Unsteady depth-varying open-channel flows are really observed in flood rivers. Owing to highly accurate laser Doppler anemometers (LDA), some valuable experimental databases of depth-varying unsteady open-channel flows are now available. However, these LDA measurements are more difficult to conduct in open-channel flows at higher unsteadiness, in comparison with unsteady wall-bounded flows such as oscillatory boundary layers and duct flows. Therefore, in this study, a low-Reynolds-number model involved with a function of unsteadiness effect was developed and some numerical calculations were conducted using the volume of fluid method as a free-surface condition. The present calculated values were in good agreement with the existing LDA data in the whole flow depth from the wall to the time-dependent free surface. These values were also compared with those of unsteady wall-bounded flows. The present calculations were able to predict the distributions of turbulence generation and its dissipation, and consequently the unsteadiness effect on turbulence structure was discussed on the basis of the outer-variable unsteadiness parameter , which is correlated with the inner-variable unsteadiness parameter in unsteady wall-bounded flows.
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Acknowledgment
The writers thank the anonymous reviewers for their critical and constructive comments.
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Information & Authors
Information
Published In
Journal of Hydraulic Engineering
Volume 132 • Issue 7 • July 2006
Pages: 681 - 695
Copyright
© 2006 ASCE.
History
Received: Feb 7, 2003
Accepted: Jul 19, 2005
Published online: Jul 1, 2006
Published in print: Jul 2006
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