Experimental study of tsunami-induced scour around a monopile foundation

Bjarke Eltard Larsen*, Lasse Kærgaard Arbøll, Sarah Frigaard Kristoffersen, Stefan Carstensen, David R. Fuhrman

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

This paper presents an experimental study of the tsunami-induced scour process around a monopile foundation, representative of those commonly used for offshore wind farms. The scour process is studied by subjecting the monopile to a time varying current, which enables a properly down-scaled experiment from the boundary layer and scour perspective. It is shown how the scaled experiments corresponds to real life idealized tsunami cases with periods ranging from 10 to 40 min. It is then shown that the boundary layers of the model tsunami are well described by recently developed empirical relations for tsunami boundary layers. By subjecting the monopile to several successive tsunami waves the scour process is shown to occur in a stepwise cumulative fashion, with the final equilibrium scour depth tending to the depth limited steady current limit. It is shown that the entire scour development can reasonably be predicted by a recently developed simple engineering model. Finally, the experimental results are compared to a fully coupled hydrodynamic and morphologic CFD model and a good correspondence is obtained.
Original languageEnglish
JournalCoastal engineering
Volume138
Pages (from-to)9-21
ISSN0378-3839
DOIs
Publication statusPublished - 2018

Keywords

  • Boundary layers
  • Computational fluid dynamics
  • Monopiles
  • Morphology
  • Scour
  • Tsunamis

Cite this

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title = "Experimental study of tsunami-induced scour around a monopile foundation",
abstract = "This paper presents an experimental study of the tsunami-induced scour process around a monopile foundation, representative of those commonly used for offshore wind farms. The scour process is studied by subjecting the monopile to a time varying current, which enables a properly down-scaled experiment from the boundary layer and scour perspective. It is shown how the scaled experiments corresponds to real life idealized tsunami cases with periods ranging from 10 to 40 min. It is then shown that the boundary layers of the model tsunami are well described by recently developed empirical relations for tsunami boundary layers. By subjecting the monopile to several successive tsunami waves the scour process is shown to occur in a stepwise cumulative fashion, with the final equilibrium scour depth tending to the depth limited steady current limit. It is shown that the entire scour development can reasonably be predicted by a recently developed simple engineering model. Finally, the experimental results are compared to a fully coupled hydrodynamic and morphologic CFD model and a good correspondence is obtained.",
keywords = "Boundary layers, Computational fluid dynamics, Monopiles, Morphology, Scour, Tsunamis",
author = "Larsen, {Bjarke Eltard} and {K{\ae}rgaard Arb{\o}ll}, Lasse and Kristoffersen, {Sarah Frigaard} and Stefan Carstensen and Fuhrman, {David R.}",
year = "2018",
doi = "10.1016/j.coastaleng.2018.04.007",
language = "English",
volume = "138",
pages = "9--21",
journal = "Coastal Engineering",
issn = "0378-3839",
publisher = "Elsevier",

}

Experimental study of tsunami-induced scour around a monopile foundation. / Larsen, Bjarke Eltard; Kærgaard Arbøll, Lasse ; Kristoffersen, Sarah Frigaard; Carstensen, Stefan; Fuhrman, David R.

In: Coastal engineering, Vol. 138, 2018, p. 9-21.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Experimental study of tsunami-induced scour around a monopile foundation

AU - Larsen, Bjarke Eltard

AU - Kærgaard Arbøll, Lasse

AU - Kristoffersen, Sarah Frigaard

AU - Carstensen, Stefan

AU - Fuhrman, David R.

PY - 2018

Y1 - 2018

N2 - This paper presents an experimental study of the tsunami-induced scour process around a monopile foundation, representative of those commonly used for offshore wind farms. The scour process is studied by subjecting the monopile to a time varying current, which enables a properly down-scaled experiment from the boundary layer and scour perspective. It is shown how the scaled experiments corresponds to real life idealized tsunami cases with periods ranging from 10 to 40 min. It is then shown that the boundary layers of the model tsunami are well described by recently developed empirical relations for tsunami boundary layers. By subjecting the monopile to several successive tsunami waves the scour process is shown to occur in a stepwise cumulative fashion, with the final equilibrium scour depth tending to the depth limited steady current limit. It is shown that the entire scour development can reasonably be predicted by a recently developed simple engineering model. Finally, the experimental results are compared to a fully coupled hydrodynamic and morphologic CFD model and a good correspondence is obtained.

AB - This paper presents an experimental study of the tsunami-induced scour process around a monopile foundation, representative of those commonly used for offshore wind farms. The scour process is studied by subjecting the monopile to a time varying current, which enables a properly down-scaled experiment from the boundary layer and scour perspective. It is shown how the scaled experiments corresponds to real life idealized tsunami cases with periods ranging from 10 to 40 min. It is then shown that the boundary layers of the model tsunami are well described by recently developed empirical relations for tsunami boundary layers. By subjecting the monopile to several successive tsunami waves the scour process is shown to occur in a stepwise cumulative fashion, with the final equilibrium scour depth tending to the depth limited steady current limit. It is shown that the entire scour development can reasonably be predicted by a recently developed simple engineering model. Finally, the experimental results are compared to a fully coupled hydrodynamic and morphologic CFD model and a good correspondence is obtained.

KW - Boundary layers

KW - Computational fluid dynamics

KW - Monopiles

KW - Morphology

KW - Scour

KW - Tsunamis

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DO - 10.1016/j.coastaleng.2018.04.007

M3 - Journal article

VL - 138

SP - 9

EP - 21

JO - Coastal Engineering

JF - Coastal Engineering

SN - 0378-3839

ER -