Simulations on Skimming Flow over a Vertical Drop Pool
Publication: Journal of Engineering Mechanics
Volume 140, Issue 7
Abstract
The installation of a drop pool in an open channel is aimed to dissipate the flow energy that diminishes the destruction of the downstream channel. Previous studies have been conducted experimentally on the hydraulic properties for flow over the pools. The numerical simulations based on the Reynolds average Navier-Stokes (RANS) equation and the renormalization group method (RNG) turbulent transport model for exploring the dynamic characteristics of the skimming flow over the vertical drop pools are presented. The simulations were conducted for a specified supercritical approaching flow on a fixed drop height but different heights of the end sill . The simulated results were verified by previous experimental results of the flow visualization and the measured mean velocity profiles. The numerical results show that the skimming flow will form in cases of where the dropping flow slides over the pool and forms a sliding jet. The pressure tends to be negative at the leading edge of the wall corner in the vertical drop area for a low-end sill. The momentum exchange between the sliding jet and pool creates a circulation flow in the pool; the major turbulent energy dissipation occurs at the momentum exchange zone. The maximum vorticity occurs at the drop corner where the sliding jet starts. The head loss of energy decreases as increases. The empirical formula of the energy loss between the approaching flows and downstream flows is presented.
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Acknowledgments
The authors are grateful to the National Science Council, Taiwan, for financial support under Grant No. NSC100-2622-E-005-001-CC1. The authors thank Dr. Wei-Jung Lin for supporting the valuable experimental images and data. The authors also thank Dr. I-Yu Wu for supporting the site picture.
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Published In
Journal of Engineering Mechanics
Volume 140 • Issue 7 • July 2014
Copyright
© 2014 American Society of Civil Engineers.
History
Received: Nov 8, 2012
Accepted: Nov 21, 2013
Published online: Nov 23, 2013
Published in print: Jul 1, 2014
Discussion open until: Jul 5, 2014
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