Numerical simulation of nonlinear long waves interacting with arrays of emergent cylinders

TL;DR

This study develops a numerical model to simulate long wave interactions with arrays of emergent cylinders, capturing complex wave behaviors and assessing their protective effects in coastal environments.

Contribution

The paper introduces a hybrid numerical approach combining Serre-Green-Naghdi and nonlinear shallow water equations for accurate wave simulation around emergent cylinders.

Findings

Cylinders provide coastal protection by reducing wave energy behind them.

Cylinders can cause local water depth amplification, affecting wave runup.

Model validation shows high accuracy against existing data.

Abstract

We presented numerical simulation of long waves, interacting with arrays of emergent cylinders inside regularly spaced patches, representing discontinues patchy coastal vegetation. We employed the fully nonlinear and weakly dispersive Serre-Green-Naghdi equations (SGN) until the breaking process starts, while we changed the governing equations to nonlinear shallow water equations (NSW) at the vicinity of the breaking-wave peak and during the runup stage. We modeled the cylinders as physical boundaries rather than approximating them as macro-roughness friction. We showed that the cylinders provide protection for the areas behind them. However they might also cause amplification in local water depth in those areas. The presented results are extensively validated against the existing numerical and experimental data. Our results demonstrate the capability and reliability of our model in simulating wave interaction with emergent cylinders.