condition, the minimum area was pushed bayward and the inlet was progressively
wider bayward and seaward from the minimum area region.
This experiment combined the 26-min tide period and the 0.26-mm-diameter
sand. After 54 tidal cycles an area of 0.125 sq m (1.347 sq ft) was reached, with
0.32-m/sec (1.05-ft/sec) maximum currents and a 22.96-cu-m (811-cu-ft) tidal
prism. Figure 11 shows the inlet at the start and end of the tide-current-only test.
As before, the sides of the inlet remained relatively straight and parallel to one
another in the absence of waves.
a. Tidal cycle 1
b. Tidal cycle 54
Figure 11. Tidal cycle 1 at start of Run 9 and tidal cycle 54 at the conclusion of the
tidal current experiment (no waves)
Appendix A presents plots of data collected from the nine runs. Included are
the minimum area versus time (elapsed time of tidal current (and wave) action),
the maximum ebb and flood current in the center of the channel during the ex-
periment, the maximum head difference between ocean and bay measured away
from the influence of the inlet, the bay tidal range versus time during the experi-
ment, and for Runs 4, 5, 8, and 9, channel cross-sectional area plots at some or all
the stations shown in Figure 4.
Discussion of Results
The runs with tide period of 105 min produced a bay response in which the
bay was nearly filled; i.e., the bay range was nearly equal to the ocean tide range.
Figure 8 shows the ocean and bay water levels during Runs 4 and 8. The bay
Chapter 4 Experiments and Results