Wave transmission of deep-draft box-type bottom-detached breakwaters

authored by
Zihan Liu, Nils Goseberg, Lorenzo Cappietti
Abstract

Expanding human activity into offshore marine areas presents significant challenges. Protecting offshore structures and the areas within them from the destructive forces of large waves is of primary importance. Bottom-founded breakwaters are effective in shallow waters, whereas floating or bottom-detached breakwaters are more suitable for deeper waters. This study explored the transmission coefficient (kt) of fixed box-type bottom-detached breakwaters (BDBs) with various dimensions under different wave conditions. A numerical wave flume based on Computational Fluid Dynamics (CFD) was validated using experimental measurements from a physical wave flume and employed to conduct a parametric study. The results indicated that the changes in wave steepness had a small effect on kt of BDBs, while significant decreases in kt were observed with the increase in relative draft (DFB/Lw) and relative width (WFB/Lw), where Lw presents wavelength. A predictive equation for kt was derived from the numerical results and validated using the numerical data and the experimental data from present and previous studies. Within WFB/Lw=0.004–0.43 and DFB/Lw = 0.001–0.21, the proposed equation demonstrated considerable accuracy with a relative error within the range of (−20 %, 20 %). The Root Mean Square Errors (RMSEs) of the kt predicted by the proposed equation and various experimental datasets were below 0.1.

Organisation(s)
Coastal Research Centre
External Organisation(s)
University of Florence (UniFi)
Technische Universität Braunschweig
Type
Article
Journal
Ocean engineering
Volume
331
ISSN
0029-8018
Publication date
22.04.2025
Publication status
E-pub ahead of print
Peer reviewed
Yes
ASJC Scopus subject areas
Environmental Engineering, Ocean Engineering
Sustainable Development Goals
SDG 14 - Life Below Water
Electronic version(s)
https://doi.org/10.1016/j.oceaneng.2025.121208 (Access: Closed)