square30_blue_1.gif  Model Application: Sogwipo Marina, South Korea

Simulation of wave reflection, refraction, diffraction, bottom friction, and breaking

sogwipo_1.gif

        Calculated wave height image showing the effect of Nakto Island on

         waves coming from south with wave period =12 s and wave height =1 m.

 

 

Sogwipo Marina is located on the south side of Cheju Island, Korea. The major waves come from the S and SSE.  Further south of the Sogwipo Marina is a smaller island, Nakto, that provides some protection to the marina.  The geography and bathymetry at this study site are complex because of Nakto Island, the peninsula, and the breakwaters. One difficulty in simulating wave transformation when wave reflection has to be considered is the selection of the proper value of .  For a rigorous selection, field or laboratory experiments must be performed.  In general, varies with wave period, beach slope, beach material, and beach structures. For this case,  was arbitrarily selected as 0.98 on boundary grids that are adjacent to land for simulating the possible energy dissipation on beaches.  On the two lateral boards, the radiation boundary condition was specified. 

The computed wave height distribution in the computation domain and wave crest lines for the 12 s waves coming from the South indicate a complicated wave transformation process caused by Nakto Island.  In many places, the original long crest waves were changed to short crest waves because of wave reflection, diffraction, and scatter. The significant wave scatter caused by Nakto Island may be because its size (~ 300 m X 500 m) is slightly larger than the deep water wave length (L0 = 225 m) for the 12 s waves. Nakto Island does provide reasonable shelter effect for the marina.   Wave heights were significantly reduced in front of the entrance to the marina.  Inside the marina, wave crest lines clearly show the wave diffraction effect. For details, see Maa et al. (2002).

 

sogwipo_2.gif

Calculated wave crest lines showing the effect of the wave scatter caused by Nakto

Island for waves coming from south with wave period =12 s and wave height =1 m.