Estimating ocean wave directional spreading from an Eulerian surface elevation time history

The directional spreading of sea states is an important design parameter in offshore engineering. Wave directionality affects the resulting wave kinematics, which affects the forces exerted on offshore structures. In this paper, we develop a method for estimating the amount of spreading, when the on...

Cijeli opis

Bibliografski detalji
Glavni autori: Adcock, T, Taylor, P
Format: Journal article
Jezik:English
Izdano: 2009
_version_ 1826274668341886976
author Adcock, T
Taylor, P
author_facet Adcock, T
Taylor, P
author_sort Adcock, T
collection OXFORD
description The directional spreading of sea states is an important design parameter in offshore engineering. Wave directionality affects the resulting wave kinematics, which affects the forces exerted on offshore structures. In this paper, we develop a method for estimating the amount of spreading, when the only information available is the time history of free surface elevation at a single point in space. We do this by predicting the second-order bound waves that occur at the difference in frequency of two freely propagating waves. The magnitude of these second-order bound waves is a function of the angle between the interacting waves. Thus, it is possible to infer some information about spreading from a single-point time history. We demonstrate that this approach works for wave groups in a fully nonlinear numerical wave tank. We create a synthetic random sea state and introduce noise into the analysis and thus show that our approach is robust and insensitive to noise, even with a signalto-noise ratio of unity in the difference waves. This approach is also applied to random waves in a physical wave tank where spreading was directly measured and also to a storm recorded in the North Sea. In all cases, we find our estimate of spreading is in good agreement with other measurements. © 2009 The Royal Society.
first_indexed 2024-03-06T22:46:57Z
format Journal article
id oxford-uuid:5d816c1b-f769-40d7-b9a7-a3f91b2c0f1d
institution University of Oxford
language English
last_indexed 2024-03-06T22:46:57Z
publishDate 2009
record_format dspace
spelling oxford-uuid:5d816c1b-f769-40d7-b9a7-a3f91b2c0f1d2022-03-26T17:34:49ZEstimating ocean wave directional spreading from an Eulerian surface elevation time historyJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:5d816c1b-f769-40d7-b9a7-a3f91b2c0f1dEnglishSymplectic Elements at Oxford2009Adcock, TTaylor, PThe directional spreading of sea states is an important design parameter in offshore engineering. Wave directionality affects the resulting wave kinematics, which affects the forces exerted on offshore structures. In this paper, we develop a method for estimating the amount of spreading, when the only information available is the time history of free surface elevation at a single point in space. We do this by predicting the second-order bound waves that occur at the difference in frequency of two freely propagating waves. The magnitude of these second-order bound waves is a function of the angle between the interacting waves. Thus, it is possible to infer some information about spreading from a single-point time history. We demonstrate that this approach works for wave groups in a fully nonlinear numerical wave tank. We create a synthetic random sea state and introduce noise into the analysis and thus show that our approach is robust and insensitive to noise, even with a signalto-noise ratio of unity in the difference waves. This approach is also applied to random waves in a physical wave tank where spreading was directly measured and also to a storm recorded in the North Sea. In all cases, we find our estimate of spreading is in good agreement with other measurements. © 2009 The Royal Society.
spellingShingle Adcock, T
Taylor, P
Estimating ocean wave directional spreading from an Eulerian surface elevation time history
title Estimating ocean wave directional spreading from an Eulerian surface elevation time history
title_full Estimating ocean wave directional spreading from an Eulerian surface elevation time history
title_fullStr Estimating ocean wave directional spreading from an Eulerian surface elevation time history
title_full_unstemmed Estimating ocean wave directional spreading from an Eulerian surface elevation time history
title_short Estimating ocean wave directional spreading from an Eulerian surface elevation time history
title_sort estimating ocean wave directional spreading from an eulerian surface elevation time history
work_keys_str_mv AT adcockt estimatingoceanwavedirectionalspreadingfromaneuleriansurfaceelevationtimehistory
AT taylorp estimatingoceanwavedirectionalspreadingfromaneuleriansurfaceelevationtimehistory