diff --git a/biblio/chapters/literature.tex b/biblio/chapters/literature.tex index 7606cdb..a6b7232 100644 --- a/biblio/chapters/literature.tex +++ b/biblio/chapters/literature.tex @@ -1,8 +1,12 @@ \chapter{Literature Review} In this chapter, literature relevant to the present study will be reviewed. +Three sections will be detailled: the separation of incident and reflected +components from wave measurements, the modelisation of wave impacts on a +rubble-mound breakwater, and the modelisation of block displacement by wave +impacts. \section{Separating incident and reflected components from wave buoy data} - +\subsection{Introduction} The separation of incident and reflected waves is a crucial step in numerically modeling a sea state. Using the raw data from a buoy as the input of a wave model will lead to incorrect results in the domain as the flow velocity at the @@ -13,7 +17,7 @@ sea states, and they can generally be categorised in two types of methods: array methods and PUV methods \parencite{inch2016accurate}. Array methods rely on the use of multiple measurement points of water level to extracted the incident and -reflected waves, while PUV methods use colocated pressure and velocity +reflected waves, while PUV methods use co-located pressure and velocity measurements to separate incident and reflected components of the signal. \subsection{Array methods} @@ -87,39 +91,75 @@ seabeds, as shoaling is not part of the underlying model. \subsubsection{Conclusion} Array methods have been developped enough to provide accurate results in a wide -range of situations. However, they require at least two wave gauges to be used. +range of situations. Sensibility to noise has been reduced, and the influence +of shoaling has been considered. Those methods can also be applied to irregular +non-linear waves. + +However, they require at least two wave gauges to be used. That means that in some situations such as the Saint-Jean-de-Luz event of 2017, other methods are needed since only one field measurement location is available. \subsection{PUV methods} +The goal of PUV methods is to decompose the wave field into incident and +reflected waves using co-located wave elevation and flow velocity measurements +\parencite{tatavarti1989incoming}. \textcite{tatavarti1989incoming} presented a +detailled analysis of separation of incoming and outging waves using co-located +velocity and wave height sensors. Their method allows to obtain the reflection +coefficient relative to frequency, as well as to separate incident and +reflected wave components. Compared to array methods, this method also strongly +reduces the influence of noise. -\begin{itemize} - \item ?? \cite{guza1977resonant}: model of the surf zone as a standing wave - combined with a progressive wave. Accurate results of surface elevation and - runup for reflectivities over 0.3. +\textcite{kubota1990} studied the influence of the considered wave theory on +incident and reflected wave separation. Three methods, based on linear +long-wave theory, small-amplitude wave theory and quasi-nonlinear long-wave +theory respectiveley were developped and compared. The results show that the +quasi-nonlinear approach gave the most accurate results. - \item ?? \cite{guza1984}: +%\textcite{walton1992} applied a separation method based on co-located pressure +%and velocity measurements on field, studying two natural beaches. This study +%showed that reflection is not significant on natural beaches. Additionnaly, the +%method that is used allowed for larger reflected energy than incident energy. - \item \cite{tatavarti1989incoming}: Decompose colocated random field - measurements of wave elevation and currenct velocity into incoming and - outgoing components. Less sensitive to noise. +Research by \textcite{hughes1993} showed how co-located horizontal velocity and +vertical velocity (or pressure) sensors can be used to extract incident and +reflected wave spectra. Their method is based on frequency domain linear +theory, and provided accurate results for full reflection of irregular +non-breaking waves. Low-reflection scenarii were evaluated against the results +from \textcite{goda1977estimation}, and showed good agreement between both +methods. \textcite{hughes1993} also highlights that reflection estimates are +unreliable for higher frequency, where coherency between the two measured +series is lower. - \item \cite{kubota1990}: comparison between different wave theories: - quasi-nonlinear long-wave theory gave the best results. +Following the work of \textcite{tatavarti1989incoming}, +\textcite{huntley1999use} showed how principal component analysis can alleviate +noise-induced bias in reflection coefficient calculations compared to +time-domain analysis. They also stuied the influence of imperfect collocation +of the sensors, showing that the time delay between sensors leads to a peak in +the reflection coefficient at a frequency related to this time delta. - \itemĀ \cite{walton1992}: application to beaches, possibility to have higher - reflected energy than incident energy. +%%% TODO? %%% +%\begin{itemize} +% \item \cite{sheremet2002observations}: +%\end{itemize} - \item \cite{hughes1993}: colocated horizontal and vertical velocities or - horizontal velocity and surface elevation. Validation for full reflection - of irregular non breaking waves. +\subsection{Conclusion} +Numerous methods have been developped in order to separate incident and +reflected components from wave measurements. Array methods rely on the use of +multiple, generally aligned, wave gauges, while PUV methods rely on the use of +co-located sensors, generally a wave height sensor and a horizontal velocity +sensor. Array methods generally have the advantage of being more cost-effective +to implement, as the cost of reliable velocity measurement devices can be +important \parencite{hughes1993}. Nevertheless, PUV methods are generally more +accurate regarding noise, varying bathymetry, and can be setup closer to +reflective surfaces \parencite{hughes1993,inch2016accurate}. - \item \cite{huntley1999use}: principal component analysis technique to avoid - noise-induced bias. - - \item \cite{sheremet2002observations}: -\end{itemize} +In the case of the 2017 event on the Artha breakwater, the results from a +single wave gauge are available, which means that the array methods are not +applicable. A PUV method \parencite{tatavarti1989incoming,huntley1999use} +should then be used to evaluate the reflection coefficient of the Artha +breakwater and to separate the incident and reflected wave components from the +measured data. \section{Modeling wave impact on a breakwater} \subsection{SPH models} diff --git a/biblio/library.bib b/biblio/library.bib index ce7f3e2..d51fdee 100644 --- a/biblio/library.bib +++ b/biblio/library.bib @@ -722,3 +722,11 @@ publisher={American Society of Civil Engineers} } +@incollection{isobe1985method, + title={Method for estimating directional wave spectrum in incident and reflected wave field}, + author={Isobe, Masahiko and Kondo, Kosuke}, + booktitle={Coastal Engineering 1984}, + pages={467--483}, + year={1985} +} + diff --git a/biblio/notes/bibliography_research.tex b/biblio/notes/bibliography_research.tex index 4a92576..7415733 100644 --- a/biblio/notes/bibliography_research.tex +++ b/biblio/notes/bibliography_research.tex @@ -54,5 +54,6 @@ barbano2010large,PARIS20111,biolchi2016} \section{Other} \cite{miche1951} +\cite{isobe1985method} \section{Flow in porous media} \paragraph{wave flow porous media} \cite{SHAO2010304}