Clear Water Scour Downstream of Log Deflectors in Horizontal Channels
Publication: Journal of Irrigation and Drainage Engineering
Volume 141, Issue 9
Abstract
Stream deflectors are in-stream hydraulic structures that limit the flow channel width, thereby accelerating the flow through the constricted section. Single-wing and double-wing log deflectors are the two most commonly used types of in-stream eco-friendly structures. The purpose of this paper is to investigate the scour phenomena downstream of log deflectors in straight horizontal channels. The main goal is to obtain design equations to predict the main scour parameters and describe the scour morphology. All the experiments have been carried out in a horizontal channel and in clear water conditions. Log deflectors with different heights and angles were tested. Different hydraulic conditions including densimetric Froude numbers, water head drops, and tailwater values were studied. Results show that the tailwater depth and deflector angle are important variables to determine the scour parameters. Dimensional analysis leads to design equations to estimate the maximum scour depth, maximum length of the scour, and maximum height and length of the dune. Two types of scour morphology downstream of log deflectors have been defined.
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Journal of Irrigation and Drainage Engineering
Volume 141 • Issue 9 • September 2015
Copyright
© 2015 American Society of Civil Engineers.
History
Received: May 10, 2014
Accepted: Dec 15, 2014
Published online: Jan 21, 2015
Discussion open until: Jun 21, 2015
Published in print: Sep 1, 2015
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