Abstract
The present study numerically investigates the breaking and spectral characteristics and geometric properties of breaking irregular waves over slopes for different incident waves. The growth of wave non-linearity and wave energy redistribution during shoaling and breaking process are observed to be major factors in determining the free surface elevation skewness and spectral bandwidth. In general, the variation of the breaker indices with the surf similarity parameter is found to be mainly governed by the type of wave breakers. The wave breaker type further depends on the seabed slope, incident wave parameters and water depth at the location of wave breaking. The study further explores the geometric properties for both spilling and plunging irregular wave breakers. The wave deformation due to wave-seabed interaction plays a major role in affecting the breaker shapes. Every individual breaking wave in the irregular wave train possesses different wave profiles and breaker characteristics. In order to study these parameters in a probabilistic way, the statistics of the breaker characteristics and the breaker shape parameters are investigated. The lognormal distribution is noticed to be the most suitable fit for the wave crest steepness and asymmetry factors. This study is performed using the open-source computational fluid dynamics (CFD) based numerical model. The numerical model is validated for a submerged bar under breaking irregular waves and the numerical results are compared with experimental data. The transformations of the free surface elevation due to wave shoaling, wave breaking and wave decomposition are explored.
Highlights
During the last few decades, considerable efforts have been made to study wave breaking in the coastal regions
For case A1 (s = 0.0142, m2 = 1:25), as the waves propagate over the slope, the energy levels from the spectral peak region E1 and low frequency range E4 are slightly reduced due to wave shoaling, and this energy is transferred to the above-peak region E2 as noticed by an increase in E2 (Fig. 7a)
The present study further investigates the geometric properties of the wave profile at breaking by using the steepness and asymmetry parameters (Fig. 15) defined by Kjeldsen and Myrhaug (1978)
Summary
During the last few decades, considerable efforts have been made to study wave breaking in the coastal regions. Alagan Chella et al (2015, 2016) studied the breaking characteristics and geometric properties of breaking regular waves over slopes using a CFD based model They compared the numerical results with experimental data by Ting and Kirby (1996). There are only a few studies performed in the past to investigate the transformations in the parameters like free surface elevation skewness, spectral bandwidth, breaking characteristics and geometric wave profile properties during the breaking process for irregular waves in shallow water over slopes. The analysis of the geometric properties of irregular wave breakers is performed for different breaker types to explore the role of seabed slope and incident wave parameters in the wave breaking process. The statistics of breaking wave characteristics and geometric properties of the breakers are analysed and discussed to quantify these parameters
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
