Wave reflections from breakwaters

A new method is presented for estimating the reflection of a random, multi-directional sea from a coastal structure. The technique is applicable to an array of wave gauges of arbitrary geometry deployed seaward of the reflector. An expansion for small oblique wave incidence angles is used to derive an approximate relationship between measured array cross-spectra and a small number of parameters that describe the incident wave properties and the reflectivity of the structure. Model tests with simulated array data demonstrate that for wave incidence angles less than about 30 deg the new technique provides accurate and robust estimates of the gross properties of incident and reflected waves. The new method is applied to array data acquired offshore of a permeable, rubble mound breakwater in Monterey Bay, California. The estimated reflection coefficients decrease approximately linearly with creasing frequency. Whereas the observed reflections depend only weakly on the incident wave energy, the fraction of the incident wave energy flux transmitted through the breakwater decreases with increasing wave energy, suggesting that dissipation is enhanced with large amplitude waves.

Department dc:contributor.department

Meteorology

Grantor dc:publisher

Monterey, California. Naval Postgraduate School

Year dc:date.issued

1994

Author dc:creator

• Dickson, William S.

Advisors dc:contributor.advisor

• Herbers, Thomas H.C.
• Thornton, Edward B.

Statement dc:rights

• This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.

Language dc:language.iso

en_US

Handle dc:identifier.uri

https://hdl.handle.net/10945/30846

OAI identifier oai:identifier

oai:calhoun.nps.edu:10945/30846