Simulation of Wave-Plus-Current Scour beneath Submarine Pipelines
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VIEW CORRECTIONPublication: Journal of Waterway, Port, Coastal, and Ocean Engineering
Volume 142, Issue 5
Abstract
A fully coupled hydrodynamic and morphologic numerical model was utilized for the simulation of wave-plus-current scour beneath submarine pipelines. The model was based on incompressible Reynolds-averaged Navier–Stokes equations, coupled with k-ω turbulence closure, with additional bed and suspended load descriptions forming the basis for seabed morphology. The model was successfully validated against experimental measurements involving scour development and eventual equilibrium in pure-current flows over a range of Shields parameters characteristic of both clear-water and live-bed regimes. This validation complements previously demonstrated accuracy for the same model in simulating pipeline scour processes in pure-wave environments. The model was subsequently utilized to simulate combined wave-plus-current scour over a wide range of combined Keulegan–Carpenter numbers and relative current strengths. The resulting equilibrium scour depths and trends were shown to be in accordance with existing experimentally based expressions from the literature. The variety of scour profile types emerging under various flow conditions is detailed and reconciled with experimental observations. The resulting matrix of scour depth time series was systematically analyzed, resulting in a new generalized expression for the scour time scale in combined wave-plus-current flow environments. This expression is fully consistent with existing experimentally based relations at both pure-current and pure-wave limits and is appropriate for engineering use.
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Acknowledgments
The authors acknowledge support from the European Union Project ASTARTE [Assessment, Strategy and Risk Reduction for Tsunamis in Europe; Grant No. 603839 (FP7-ENV-2013.6.4-3)]. The third author additionally acknowledges Innovative Multi-purpose Offshore Platforms: Planning, Design and Operation (MERMAID), 20122016, Grant Agreement No. 288710 of European Commission, 7th Framework Programme for Research.
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Journal of Waterway, Port, Coastal, and Ocean Engineering
Volume 142 • Issue 5 • September 2016
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© 2016 American Society of Civil Engineers.
History
Received: May 26, 2015
Accepted: Jan 28, 2016
Published online: Mar 15, 2016
Discussion open until: Aug 15, 2016
Published in print: Sep 1, 2016
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