47 lines
1.9 KiB
TeX
47 lines
1.9 KiB
TeX
\chapter{SWASH model}
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\section{1D model}
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In order to find out if the reflection induced by the breakwater has an
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influence on the sea state at the buoy's location, a one-dimensional model of
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the zone between the buoy and the breakwater was created.
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The considered domain is \SI{1450}{\m} long, with \SI{1250}{\m} between the
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buoy and the breakwater, and a further \SI{200}{\m} offshore of the buoy.
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The model is a 10 layers swash model accounting for porous media in near the
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breakwater. The model was adapted from PA Poncet.
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\subsection{Model 1}
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A first run was produced in order to test the model with a water level of
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\SI{0.5}{\m} using the measured spectrum from 2017-02-28 as the offshore
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boundary condition and a sommerfeld radiation condition on the breakwater
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boundary. The model was run over a duration of 30 minutes.
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The same model was implemented without the breakwater (by forcing a minimum
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depth) with an added \SI{250}{\m} sponge layer at the shorewards boundary.
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The reflection coefficient at the buoy's location was computed using
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a PUV method \parencite{huntley1999use}.
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The results are displayed in \autoref{fig:swash_1_R}. Two methods of
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calculating the reflection were used \parencite{huntley1999use}, the second one
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might be wrongly implemented, and the first one might be subject to
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noise-induced bias.
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\begin{figure}
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\centering
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\includegraphics{R1.png}
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\includegraphics{R2.png}
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\caption{Reflection coefficient computed with Swash. 1: With breakwater; 2:
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Without breakwater.}\label{fig:swash_1_R}
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\end{figure}
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\subsection{Model 2}
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An attempt at running the model with the correct water level (\SI{4.5}{\m}) was
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made without success, as the model does not seem to be able to compute
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overtopping. Changing the boundary condition at the breakwater does not fix the
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issue, and the model is not able to run with water on both sides of the
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breakwater as the initial condition.
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