depth changes commence. Hopefully, this will be a distance of at least three or four wavelengths from the

entrance. This diffraction analysis will define the wave heights and crest orientation at the point where

significant shoaling-refraction effects commence. From this point landward, a refraction-shoaling analysis

using the procedures described in Part II-3 can be used to carry the wave to the point of breaking or

interaction with a land boundary.

(1) A computer program for dealing with combined diffraction and reflection by a vertical wedge has

been developed by Seelig (1979, 1980) and is available in the Automated Coastal Engineering System

(ACES) (Leenknecht et al. 1992). This package estimates wave height modifications due to combined

diffraction and reflection caused by a structure. It has the ability to simulate a single straight, semi-infinite

breakwater, corners of docks, and rocky headlands. Assumptions include monochromatic, linear waves, and

constant water depth.

(2) The user has the ability to vary the wedge angle from 0 to 180 deg, where 0 deg would represent the

case of a single straight, semi-infinite breakwater and 90 deg, the corner of a dock.

(3) The required input includes incident wave height, wave period, water depth, wave angle, wedge

angle, and X and Y coordinates (location of desired calculation). The range of X and Y should be limited

to plus or minus 10 wavelengths.

Harbor Hydrodynamics

II-7-13

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