Experiments on droplet production from solitary waves impacting on a vertical wall

Abstract

This work presents the results of an experimental investigation of solitary waves impacting on a vertical flat wall. The aim of the study was to correlate the wave characteristics and breaking stage before impact to the droplet production after the impact. The main characteristic of these experiments is that the wall height is lower than the wave height. The droplet sizes were obtained by combining 3D particle tracking velocimetry with an in-house code. Droplet diameters between 0.3–22 mm were measured at a distance of 35 cm and 68 cm from the wall. It was found that the breaking stage before the impact has a large influence on the mean size of the droplets produced, especially when there is air trapped between the wall and the wave at the impact moment. It was found that the mean droplet size decreases with the ratio of water jet velocity after impact and the wave speed. The resulting distributions of droplet sizes were compared to three different theoretical models used in other droplet production studies. Results were also compared to previous experimental studies of droplet formation from breaking waves to determine the best fit to the experimentally obtained distribution.