A novel and simple passive absorption system for wave-current flumes

Abstract

The physical limitations of experimental facilities, such as the walls and downstream gate of wave-current flumes, can cause excessive wave reflection. Wave reflection in wave or wave -current flumes is a key phenomenon that often leads to deviations between physical model results and prototype results. If a flume is not equipped with wave absorption systems, either active or pas-sive, in addition to the model's inaccurate representation of reality, there will be a tendency for the wave paddles to reach the maximum stroke, leading to the abrupt stoppage of the wave generation during the experiments. This research a novel and simple passive wave absorption system in the context of physical modelling studies of scour in the environment of offshore renewable energy tech-nologies. The tests were conducted in the wave-current flume of the Hydraulics Laboratory of FEUP. The results show that the new system reduced the wave reflection coefficient to values within the recommended references for physical modelling studies in offshore engineering. Design hydro-dynamic conditions showed reflection coefficients between 11 and 14.5%, and tests without currents revealed reflection coefficients between 7.5 and 10%. This study also highlights how the novel sys-tem can easily be adapted to other wave-current flumes and hydrodynamic conditions found in other hydraulics laboratories. (c) 2023 The Authors. Published by Elsevier BV on behalf of Faculty of Engineering, Alexandria University This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/).