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EE - Escola de Engenharia

URI permanente desta comunidadehttps://rihomolog.furg.br/handle/1/512

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Resultados da Pesquisa

Agora exibindo 1 - 2 de 2
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    Wave propagation in jettied entrance channels. II: observations
    (1991) Melo Filho, Eloi; Guza, Robert
    Field measurements of surface gravity waves along the center line of the straight, 1 km long, 8 m deep, 250 m wide Mission Bay entrance channel (bounded by rubble-mound jetties) are compared to a model developed in a companion paper by Melo and Guza. The observations show a rapid downchannel decay of wave energy. Additionally, the observed ratio of significant wave heights between any two stations along the channel axis is rather constant despite the different wave and current conditions encountered. The model, with all empirical coefficients determined with existing parameterizations, agrees qualitatively well with these observations. These model results are insensitive to the details of the motions and dissipation occurring within the jetties so long as an appropriate amount of energy is lost at these lateral boundaries. The wave height on the center line of a wide channel with highly absorptive jetties is controlled by diffraction. In fact, the observations and model results on the center line at Mission Bay are similar to previously published simplified models with the jetties replaced by strips of appropriate bottom dissipation and also to the decay along the center line of a breakwater gap with the gap width equal to the entrance channel width.
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    Wave propagation in jettied entrance channels. I: models
    (1991) Melo Filho, Eloi; Guza, Robert
    A model for the propagation of sea and swell waves in a channel bounded by rubble-mound jetties is presented. The model combines elements of earlier work on waves normally incident on a breakwater with a modified diffraction model based on the linear mild-slope equation. For grazing-angle (relative to the jetty axis) wave incidence, a parabolic approximation to the governing equation is used to obtain numerical solutions for monochromatic long waves propagating down the channel. An initially plane wave evolves into a spatially complex pattern as dissipation occurs along the jetties and energy is drawn from the channel interior by diffraction. Comparisons of the model to field observations are presented in a companion paper.