PIV measurements of velocities and accelerations under breaking waves on a slope

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Abstract

Understanding the physics of breaking waves is an ongoing research topic, not only due to human curiosity, but also due to the influence breaking waves have on offshore structures. In recent years, the development in experimental methods has facilitated a new insight into the physics of breaking waves. In this study, we have investigated the wave kinematics under steep and breaking waves on a laboratory beach with a slope of 1/25. The velocity field was measured by use of Particle Image Velocimetry (PIV) at a sample rate of 96Hz. The high sample rate allowed for the accelerations to be determined directly from the sampled velocities. It was found that both velocities and accelerations differ from the ones predicted from common wave theories such as streamfunction theory. This was especially evident at the top part of the wave close to the surface. This was not surprising, since the breaking event is a highly non-linear process. The results presented here may facilitate computations of the impact force on offshore structures and furthermore be used for validation of CFD models while altogether shedding light on the mechanisms behind breaking waves.
Original languageEnglish
Article number7837
JournalGeophysical Research Abstracts
Volume19
Number of pages1
ISSN1607-7962
Publication statusPublished - 2017
EventEGU General Assembly 2017: European GEosciences Union 2017 - Vienna, Austria
Duration: 24 Apr 201728 Apr 2017
http://www.egu2017.eu

Conference

ConferenceEGU General Assembly 2017
CountryAustria
CityVienna
Period24/04/201728/04/2017
Internet address

Cite this

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title = "PIV measurements of velocities and accelerations under breaking waves on a slope",
abstract = "Understanding the physics of breaking waves is an ongoing research topic, not only due to human curiosity, but also due to the influence breaking waves have on offshore structures. In recent years, the development in experimental methods has facilitated a new insight into the physics of breaking waves. In this study, we have investigated the wave kinematics under steep and breaking waves on a laboratory beach with a slope of 1/25. The velocity field was measured by use of Particle Image Velocimetry (PIV) at a sample rate of 96Hz. The high sample rate allowed for the accelerations to be determined directly from the sampled velocities. It was found that both velocities and accelerations differ from the ones predicted from common wave theories such as streamfunction theory. This was especially evident at the top part of the wave close to the surface. This was not surprising, since the breaking event is a highly non-linear process. The results presented here may facilitate computations of the impact force on offshore structures and furthermore be used for validation of CFD models while altogether shedding light on the mechanisms behind breaking waves.",
author = "Vested, {Malene Hovgaard} and Stefan Carstensen and Christensen, {Erik Damgaard}",
year = "2017",
language = "English",
volume = "19",
journal = "Geophysical Research Abstracts",
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}

PIV measurements of velocities and accelerations under breaking waves on a slope. / Vested, Malene Hovgaard; Carstensen, Stefan; Christensen, Erik Damgaard.

In: Geophysical Research Abstracts, Vol. 19, 7837, 2017.

Research output: Contribution to journalConference abstract in journalResearchpeer-review

TY - ABST

T1 - PIV measurements of velocities and accelerations under breaking waves on a slope

AU - Vested, Malene Hovgaard

AU - Carstensen, Stefan

AU - Christensen, Erik Damgaard

PY - 2017

Y1 - 2017

N2 - Understanding the physics of breaking waves is an ongoing research topic, not only due to human curiosity, but also due to the influence breaking waves have on offshore structures. In recent years, the development in experimental methods has facilitated a new insight into the physics of breaking waves. In this study, we have investigated the wave kinematics under steep and breaking waves on a laboratory beach with a slope of 1/25. The velocity field was measured by use of Particle Image Velocimetry (PIV) at a sample rate of 96Hz. The high sample rate allowed for the accelerations to be determined directly from the sampled velocities. It was found that both velocities and accelerations differ from the ones predicted from common wave theories such as streamfunction theory. This was especially evident at the top part of the wave close to the surface. This was not surprising, since the breaking event is a highly non-linear process. The results presented here may facilitate computations of the impact force on offshore structures and furthermore be used for validation of CFD models while altogether shedding light on the mechanisms behind breaking waves.

AB - Understanding the physics of breaking waves is an ongoing research topic, not only due to human curiosity, but also due to the influence breaking waves have on offshore structures. In recent years, the development in experimental methods has facilitated a new insight into the physics of breaking waves. In this study, we have investigated the wave kinematics under steep and breaking waves on a laboratory beach with a slope of 1/25. The velocity field was measured by use of Particle Image Velocimetry (PIV) at a sample rate of 96Hz. The high sample rate allowed for the accelerations to be determined directly from the sampled velocities. It was found that both velocities and accelerations differ from the ones predicted from common wave theories such as streamfunction theory. This was especially evident at the top part of the wave close to the surface. This was not surprising, since the breaking event is a highly non-linear process. The results presented here may facilitate computations of the impact force on offshore structures and furthermore be used for validation of CFD models while altogether shedding light on the mechanisms behind breaking waves.

M3 - Conference abstract in journal

VL - 19

JO - Geophysical Research Abstracts

JF - Geophysical Research Abstracts

SN - 1607-7962

M1 - 7837

ER -