Breaking occurrence and dissipation in shortcrested waves in finite water
Umniya Al Khalili, Ioannis Karmpadakis
Abstract
The understanding of wave breaking has long been a critical concern for engineers and scientists. However, accurately identifying the onset of breaking and quantifying the associated energy dissipation remain significant challenges. To address this, the present study develops a novel methodology to identify breaking wave events in shortcrested seas in finite water depths. This is achieved through a unique dataset which couples laboratory and numerically generated waves. The data reflect realistic sea-states used in engineering design and cover a wide range of conditions from mild to extreme. Using the proposed algorithm, key physical properties of breaking waves are examined. In particular, the probability of wave breaking and the associated wave energy dissipation are quantified to provide a statistical description of their behaviour. Complementarily, waves exhibiting significant nonlinear amplifications are also identified and modelled in a similar manner. This enables traditional wave distributions to be decomposed into more detailed distributions of breaking and non-breaking waves. These insights are combined to define a new model that predicts crest height statistics in intermediate water depths. This new mixture model is shown to reproduce experimental measurements with high accuracy, while also providing critical additional information about wave breaking.