| Title |
Numerical Study on a Dominant Mechanism of Rip Current at Haeundae Beach: Honeycomb Pattern of Waves |
| Authors |
최준우(Choi, Junwoo) ; 박원경(Park, Won Kyung) ; 배재석(Bae, Jae Seok) ; 윤성범(Yoon, Sung Bum) |
| DOI |
https://doi.org/10.12652/Ksce.2012.32.5B.321 |
| Keywords |
이안류;수치모의;비선형 Boussinesq 방정식;벌집구조;해운대 rip current;numerical simulation;nonlinear boussinesq equation;honeycomb pattern;haeundae beach |
| Abstract |
Two regular progressive wave trains, the directions of which are slightly different from each other, develop a honeycomb pattern of wave crests due to their nonlinear interaction. In the honeycomb pattern of wave crest, the nodal line area, which has very low wave energy, is formed. When the honeycomb pattern is developed near the beach area, rip current evolves through the nodal line area formed in the cross shore direction. In this study, to confirm that the formation of honeycomb pattern of waves near the beach area is a dominant mechanism of rip current occurred at Haeundae beach, we performed a numerical simulation of nearshore circulation at Haeundae beach under an unidirectional and monochromatic wave condition by using a nonlinear Boussinesq equation model. As a result, wave refraction due to topographical characteristics (i.e., submerged shoal) of Haeundae gave rise to several wave trains propagating with slightly different directions toward the beach, and consequently rip currents well developed through the nodal line area of honeycomb patterns of wave crest. In addition, we found that a narrow-banded spectral wave condition (i.e., a swell spectrum) increases more likelihood of rip current than a broad-banded spectral wave condtion based on the simulations employing various wave spectra with an equivalent wave height and period. |