Effects of Wave Coherence on Longshore Variability of Nearshore Wave Processes

Abstract

Since Young's (1802) double-slit experiment with optical waves, wave coherence has been studied in various scientific fields including quantum mechanics and engineering. Wave coherence happens when two intersecting waves have identical wave frequency, waveform, and constant phase difference and result in a stationary wave interference in the wavefield. Despite the importance of the subject in various scientific fields, it has not been studied broadly for the water waves. In one of the earliest studies of coherent waves, Dalrymple (1975) investigated the longshore variation of the mean water level as well as the wave height and wave-induced circulation due to the existence of intersecting waves with equal frequencies. He showed that alongshore variation of wave height due to the presence of two coherent waves results in nodal and anti-nodal points alongshore, and rip currents are formed at nodal lines with zero wave height. Following his work, Z. Wei and Dalrymple (2017) carried out numerical experiments with the Lagrangian-based smooth particle hydrodynamics (SPH) model using two intersecting waves of the same period and confirmed the

Phase‐Resolved Modeling of Wave Interference and Its Effects on Nearshore Circulation in a Large Ebb Shoal‐Beach System

“…The wave input conditions for the Boussinesq model are based on wave bulk parameters resulting from the large‐domain model, NearCoM (Shi et al., 2011). The JONSWAP spectrum with γ = 3.3 and the directional spreading parameter σ θ = 10° was partitioned into 1125 wave components, which are randomly phased with zero‐coherence (Salatin et al., 2021). The water depth is adjusted based on the tidal level recorded at the NOAA station 9414290.…”

“…For irregular wave applications, the model is equipped with an internal wavemaker (see Wei et al., 1999) that can generate monochromatic or directional spectral waves based on bulk parameters or measured spectral data. Recently, the wavemaker has been revised to address the problem of spurious spatial correlations occurring in irregular waves, resulting from discretization of target spectra over a uniform grid of frequencies and alongshore wavenumbers (Salatin et al., 2021).…”

Numerical Modeling of Nearshore Wave Transformation and Breaking Processes in the Yellow River Delta with FUNWAVE-TVD Wave Model

“…Internal wavemaker introduces a source function into the continuity equation to generate both regular and irregular waves corresponding to a given frequency and directional spectrum. Regarding the formulation of the wavemaker, this study adopted the newly proposed wavemaker developed by Salatin et al [44], which considers the degrees of wave coherence. The wave energy spectrum of the FUNWAVE-TVD model was discretized in both frequency and direction.…”

“…This recent development of wavemaker formulation enables modelers to investigate the impact of wave coherence on hydrodynamic processes with respect to different coherent levels. Detailed formulae and descriptions of the newly proposed wavemaker and its components can be found in Salatin et al [44].…”

“…Numerous efforts have been devoted to avoiding am-biguity in this problem, such as increasing the discretization in both wave direction and frequency [42] or the proposed method for the discretization of the input spectrum [17,43]. Furthermore, Salatin et al [44] proposed a new wavemaker, which is a generalized form of the default wavemaker in the FUNWAVE-TVD model that can eliminate and control the degree of wave coherence [44].…”