Greenwater due to plunging breaking wave impingement on a deck structure. Part 1: Experimental investigation on fluid kinematics

Abstract

This study experimentally investigates the kinematics of greenwater resulting from plunging breaking wave impacts on a deck structure. Two impingement scenarios, characterized by different breaking points, were considered. The ensemble-averaged flow fields were obtained by applying both PIV (particle image velocimetry) and BIV (bubble image velocimetry) techniques to 50 repeated tests. The study examines flow patterns, velocity fields, and derived quantities from velocity data to identify differences in flow behaviors, variations in velocity magnitude, and potential distribution of peak impact pressures. The presented results provide useful information and indication for assessing concentrated loadings and enhancing our understanding of hydrodynamic behaviors. Additionally, the validity of applying Ritter dam break solutions to describe the horizontal velocity distribution of greenwater flows is examined, and prediction equations based on self-similar horizontal velocity distribution are derived.