Front Wall and In-Chamber Impact Loads on a Breakwater-Integrated Oscillating Water Column

Abstract

Large-scale tests (about 1:9 of full scale) were carried out at the Large Wave Channel (GWK) on Oscillating Water Column (OWC) wave energy converters to analyse loading and water column behaviour over a wide range of wave steepnesses. The paper shows that prediction methods for non-impulsive wave loads and impulsive wave loads developed for conventional e ca b ea a e ca be ada ed OWC a ad e ac (). T e a e ad analysis demonstrates that the impact probability method from project Probabilistic Design Tools for Vertical Breakwater (PROVERBS) estimates well the proportion of impacts experienced. Observations within the OWC chamber provide new insight on water column behaviour, c d ee d e e c a ca ac d e a : e ac , cce a ac , a d a e c ac. T e e de a e c d at risk of violent impact inside the chamber.

Duct Attachment on Improving Breaking Wave Zone Energy Extractor Device Performance

“…The y-axis shows the impact pressure measured, normalized using the hydrostatic pressure (ρgH) where ρ is water density at 25 • C, g is gravitational acceleration, and H is the wave height of 0.07 m. The x-axis, on the other hand, represents the location of the measurement relative to the breaking position (zero value) and normalized with the shallow water wavelength in accordance with the linear wave theory of period (T) = 0.057 s. As demonstrated in Figure 8, the swl impact pressure is at its highest at or near the breaking wave for the bare turbine case (blue circle), up to about 5.5 times the hydrostatic pressure. This result agrees with the impact pressure measured by [35][36][37] on a vertical wall breakwater. When placed on the broken wave zone (positive x-axis value), the pressure is drastically reduced until x/L = 0.1 and then rises again.…”

The Influence of the Chamber Configuration on the Hydrodynamic Efficiency of Oscillating Water Column Devices

“…This reduction in the efficiency is explained by the fact that the energy transfer due to the wave motion over small periods is reduced when the front barriers are greater in thickness. However, in a real scenario, during severe storm events, or during times of high water levels, the front barrier is subjected to high loads, due to direct wave action [36][37][38][39], and a slender front wall cannot offer protection to the whole system, as occurred at the MWEP [12]. Therefore, special consideration should be given to this structural aspect.…”

Numerical investigation of the hydrodynamic properties of oscillating water column air chambers

“…The ocean occupies nearly 71% of the earth's surface area and is rich in energy, of which wave energy is an important component [1][2][3][4][5][6][7][8][9] . Wave energy is a promising source of clean energy because it not only generates electricity for a long time but also does not require land.…”

“…Figure 5.Frequency spectrum of the incident wave surface at different wave heights As shown in figure 4,. the relative amplitude changes with wave period for four groups of wave amplitudes, it can be seen that there is a more obvious resonance frequency of the device, and at the resonance frequency, the relative amplitude of the air chamber reaches the maximum and the overall efficiency is the highest.…”