Periodic seabed undulations, such as nearshore sandbars, are known to reflect incoming surface waves of twice the wavelength by the so-called Bragg resonance mechanism. In view of this property, longshore seabed-mounted bars were proposed long ago as a means of coastal protection against the high momentum of incident oceanic waves. Many theoretical, computational, experimental and field measurements were conducted to understand their effectiveness in shielding the shore. The idea, nevertheless, proved impractical when Yu and Mei (JFM 2000, [1]) showed that due to an inevitable finite reflection from the shoreline, energy can get trapped in the area between the shoreline and the patch of bars eventually resulting in a much higher wave energy flux impinging the shoreline. Here we propose an arrangement of oblique bars that shelters the shore by diverting, rather than reflecting, shore-normal incident waves to the shore-parallel direction. A protected buffer zone is thus created at the shoreline. We show that this novel arrangement can very efficiently shelter the shore, is almost insensitive to the distance between the bottom corrugations and the shoreline, is relatively robust against frequency detuning, and will discuss that it can be designed to protect the shore against almost the entire broadband spectrum of incident waves.

This content is only available via PDF.
You do not currently have access to this content.