Jet Scour around Vertical Pile
Publication: Journal of Waterway, Port, Coastal, and Ocean Engineering
Volume 122, Issue 2
Abstract
This study investigates the mechanism and the characteristic parameters affecting local scour around a vertical pile caused by turbulent circular wall jets. There are two basic scouring mechanisms: the pile obstruction and the jet diffusion mechanisms. The former is dominated by a horseshoe vortex system while the latter is controlled by the bed shear stress as the jet diffuses into the flow. Four types of equilibrium scour hole profiles were identified. The criteria for each type of profile are classified in terms of the densimetric Froude number Fo and the relative impingement distance X i /d o. Semiempirical equations were developed to delineate the boundary limits for the different profiles. The results show that the maximum equilibrium scour depth d se and the scour depth at the pile d pe are highly dependent on Fo ; and generally for large Fo, d se =d pe. The scour depths are insensitive to the relative size of the pile to jet diameter D /d o. However, X i /d o does not appear to affect d se /d o but it has a profound influence on d pe /d o.
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Information & Authors
Information
Published In
Journal of Waterway, Port, Coastal, and Ocean Engineering
Volume 122 • Issue 2 • March 1996
Pages: 59 - 67
Copyright
Copyright © 1996 American Society of Civil Engineers.
History
Published online: Mar 1, 1996
Published in print: Mar 1996
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