Abstract
The present study explores the performance of an array of cylindrical oscillating water column (OWC) devices, having a vertical symmetry axis, placed in front of a bottom seated, surface piercing, vertical breakwater. The main goal of this study is the investigation of a possible increase in the power efficiency of an OWC array by applying, in the vicinity of the array, a barrier to the wave propagation, aiming at amplifying the scattered and reflected waves originating from the presence of the devices and the wall. To cope with the set goal, a theoretical analysis is presented in the framework of linear potential theory, based on the solution of the proper diffraction, and pressure-radiation problems in the frequency domain, using the image theory, the matched axisymmetric eigenfunction expansion formulation, and the multiple scattering approach. Numerical results are presented and discussed in terms of the expected power absorption by the OWCs comparing different array’s characteristics i.e.,: (a) angle of incidence of the incoming wave train; (b) distances from the breakwater; and (c) geometric characteristics of the different arrangements. The results show that compared to the isolated OWC array (i.e., no presence of the wall), the power efficiency of the OWCs in front of a breakwater is amplified at specific frequency ranges.
Highlights
Sea waves have enormous power, the construction of structures for mitigating such power is not accomplished
Concerning the fixed breakwaters, they operate by reflecting the incoming wave train, as a bottom mounted rigid structure
Pile breakwaters comprise a series of piles which partially attenuate the wave energy due to turbulences and eddies created around the solids, preventing effectively the soar from sediment siltation [12,13,14]
Summary
Sea waves have enormous power, the construction of structures for mitigating such power is not accomplished. Breakwaters are widely used in coastal and offshore engineering, frequently applied in coastal protection and restoration schemes They are barriers, either water-surface piercing or submerged, that are frequently displaced perpendicularly to the dominant direction of the incoming waves, which absorb, diffract, and reflect part of the wave energy, reducing the amount of energy that reaches the shoreline. A seawall breakwater is a most common defensive structure, acting as one large solid block at locations where the ocean environments are dominating at the coast. It is usually composed of prefabricated reinforced concrete caissons, representing a better alternative in terms of performance, construction rapidity, standardization, environmental implications, and construction and maintenance costs when compared with the rubble mound type [8]. Barrier type of breakwater consists of perforated and slotted structures, operating as permeable breakwaters, increasing wave reflection as their porosity increases [15,16]
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call