Reflection of irregular waves from perforated-wall caisson breakwaters

Citation
Kd. Suh et al., Reflection of irregular waves from perforated-wall caisson breakwaters, COAST ENG, 44(2), 2001, pp. 141-151
Citations number
22
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Civil Engineering
Journal title
COASTAL ENGINEERING
ISSN journal
0378-3839 → ACNP
Volume
44
Issue
2
Year of publication
2001
Pages
141 - 151
Database
ISI
SICI code
0378-3839(200112)44:2<141:ROIWFP>2.0.ZU;2-D
Abstract
An analytical model has been developed that predicts the reflection of irre gular waves normally incident upon a perforated-wall caisson breakwater. To examine the predictability of the developed model, laboratory experiments have been conducted for the reflection of irregular waves of various signif icant wave heights and periods impinging upon breakwaters having various wa ve chamber widths. For frequency-averaged reflection coefficients, though t he overall agreement is fairly good between measurement and calculation, th e model somewhat over-predicts the reflection coefficients at larger values , and under-predicts at smaller values. The model also underestimates the e nergy loss coefficients as wave reflection becomes larger. These difference s occur because the model neglects the evanescent waves near the break-wate r, which increase the energy loss at the perforated wall. The frequency-ave raged reflection coefficient shows a minimum when the wave chamber width is approximately 0.2 times the significant wavelength, and it decreases with increasing wave steepness. Finally, it is shown that the reflection of irre gular waves from a perforated-wall caisson breakwater depends on the wave f requency, so that the reflected wave spectrum shows a frequency dependent o scillatory behavior. (C) 2001 Elsevier Science B.V. All rights reserved.