Laboratory Effects in Beach Studies. Volume VII. Movable-Bed Experiments with H sub o/L sub o = 0.013.
COASTAL ENGINEERING RESEARCH CENTER FORT BELVOIR VA
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In two experiments with a wave period of 2.35 seconds on an initial movable-bed slope of 0.10 in tanks 6 and 10 feet wide, significant differences in profile shape and wave height variability developed. Secondary wave and re-reflection effects resulting from the 38.3-foot difference in distance from the wave generator to the profile toe caused differences in the shape of the offshore zone. The 0.15-foot gap at the end of the generator blade in the 10-foot tank and the critical combination of wavelength and tank width generated a transverse wave. The transverse wave affected the profile shape--the shoreline became skewed, the depth over the shelf in the offshore zone increased laterally, and changes in the inshore zone progressed from one side of the tank to the other during the course of the experiment. The reflection coefficient, K sub r, varied from 0.03 to 0.14 in the 6-foot tank and the average in the 10-foot tank varied from 0.11 to 0.24, with considerable lateral variation. Changes in K sub r in the 10-foot tank correlate well with changes in the shape of the upper part of the offshore zone. The profile in the 6-foot tank reached equilibrium, while the profile in the 10-foot tank continued to change. Author
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