PART V: MODEL APPLICATIONS 



General Comments 



94. General guidance concerning RCPWAVE applications is provided in 

 this section. Two model applications are given to demonstrate the different 

 scales of prototype problems for which the model can be applied successfully. 

 The next two sections explain each example in greater detail. Listings of JCL 

 files used to run each simulation are provided, as are listings of input files 

 and printed output. Comparisons between model execution costs incurred on 

 both CDC computers are given in the last section. 



95. Whenever RCPWAVE is a candidate for solving a wave propagation 

 problem, the area of interest is well defined, and wave conditions to be simu- 

 lated are known. The user must create a finite difference grid system encom- 

 passing the area. Grid characteristics determine the success of the applica- 

 tion, so they should be given considerable thought. Two factors completely 

 define the grid, orientation of the axes, and cell resolution. 



96. Users should construct the grid system so that the y-axis runs as 

 parallel to the coastline as possible. This causes the x-axis to be directed 

 offshore and probably somewhat perpendicular to the bottom contours. The lat- 

 eral boundary conditions used in the model are most accurate when this axis 

 configuration is adopted. The boundary conditions assume that the variation 

 of the bathymetry, and wave parameters, in the y-direction is small. The as- 

 sumption is most accurate when the y-direction is essentially the longshore 

 direction. Ideally this axis configuration also results in the offshore ba- 

 thymetry having fairly straight and parallel contours and the offshore rows of 

 cells having the greatest depths. The procedure of applying Snell's law to 

 propagate wave information from deep water to the seaward boundary of the 

 model is more accurate if these conditions exist. 



97. Waves will generally attempt to advance in directions parallel to 

 the x-axis as a result of the recommended orientation. The model tends to 

 produce erroneous results if computed waves attempt to propagate parallel to 

 the y-axis (wave angles near plus or minus 90 deg) . Even with this axis con- 

 figuration, problems may arise due to very irregular bottom bathymetry and/or 

 very oblique wave incidence. These errors manifest themselves via large local 

 wave angles and occurrences of very large and very small wave heights in 



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