8.3 Rectangular Harbor - Resonance
In this example, we examine the influence of bottom friction on dispersion of wave
energy by friction for resonating waves in a rectangular harbor. The open boundary and
harbor dimensions are shown in Figure 18. Theoretical and lab data for this case were
presented in Ippen and Goda (1963), Lee (1971) and Chen (1986). Ippen and Goda
(1963) showed that linear theory predicts amplitudes that are too large near the resonant
reflection on the amplitudes. Laboratory data was collected at the center of the back wall
of the harbor (Lee, 1969).
Model input conditions were obtained from Lee (1969) and Chen (1986). Table 4
summarizes the input wave conditions.
Table 4. Model Input Data
Amplitude
kl
Amplitude
Kl
.13
0.2
.30
1.8
.13
0.4
.25
2.0
.13
0.6
.25
2.5
.13
0.8
.30
3.0
.13
1.0
.25
3.5
.13
1.1
.35
4.0
.38
1.2
.35
4.2
.38
1.3
.35
4.4
.25
1.4
.25
4.6
.25
1.5
.30
4.8
.25
1.6
.30
5.0
The term k is the wave number and l (0.3111 m) is the length of the harbor. Variations in
the friction coefficient and coastal reflection were considered. Waves were normally
incident to the exterior boundary for all model runs.
Results for a fully reflecting harbor are shown in Figures 19, 20 and 21. The
results of linear CGWAVE run without friction show a good match to the analytical
solution of Ippen and Goda (1963) (Figure 19). Figure 20 shows that the amplification at
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