Session: 06-08-02 Model Tests

Submission Number: 156752

Experimental Investigation of 3D Reflection in an Ocean Basin 

Traditionally, wave basins are equipped with wave generators and absorbers, the efficiency of the latter being typically described by frequency-dependent reflection coefficients. The definition of the reflection coefficient usually assumes a wave field only composed of an incident and a reflected wave component, both long-crested.

This study presents an experimental investigation of the 3D aspects of wave reflection across a wave basin. For that purpose, a series of tests were conducted in the Ocean Basin at SINTEF Ocean. The tests included both regular and irregular long-crested waves, and the free-surface elevation was measured over a large area of the basin. Reflection was defined as the set of wave components appearing in the basin after a given time, corresponding to the time it takes for the energy of the waves to cross the basin. Linear wave theory was assumed for both interpolating and extrapolating the data, thus leading to a mapping of the reflected waves over the whole surface of the basin. The amplitude of the extracted reflected waves was compared to the reflection coefficient obtained through traditional techniques. It was found that the reflected waves were multidirectional and inhomogeneous, and that extrapolation of the reflected waves with time reversal allowed to assess the sources of reflection better.

Presenting Author: Sébastien Laflèche SINTEF Ocean

Presenting Author Biography: Sébastien Laflèche is a Research Scientist at SINTEF Ocean. He recently graduated as a PhD from the department of Marine Technology at NTNU. He is part of SFI BLUES, a joint industry-academia centre for research on new floating structures. His work focuses on the wave quality in experiments with large floating structures, and on the description of inhomogeneous wave fields.