Spectral analysis of waves produced by HSC for coastal management

Abstract

The present study focuses on wake wash management in the Bay of Naples by time variant spectral analysis to establish more reliable operational strategies and mitigative measures. The time frequency analysis of several wake wash signals due to high-speed craft (HSC), both catamarans and monohulls, operating in the Gulf of Naples is carried out to derive the time-energy per unit area distribution and better characterize the wake wash event and relevant spectrum. A new spectral analysis procedure, which allows to filter the wind sea wave component, is proposed to evaluate the only wake wash component and to estimate both wake wash height and energy density. In this respect, in fact, the influence of wind sea waves may lead to more reliable coastal management guidelines and wake wash measures, even if the measurement campaign has been carried out under calm met-ocean conditions. A comparative study with wake wash values determined by time history analysis is finally carried out, showing that spectral analysis can be applied with good confidence for coastal management purposes, leading to more accurate and reliable operational strategies.