해안선에 평행한 단일 잠제 후면 연안 흐름패턴 관측 수리실험

국문 초록 (Abstract)

해안선 변동을 제어하기 위해 설치되는 잠제의 효과를 이해하기 위해 해안선과 평행한 단일 잠제 주변 연안의 흐름변화 특성을 수리실험을 통해 연구하였다. 잠제와 입사파 파라미터에 따른 잠제 후면의 흐름패턴을 관측하기 위해 LSPIV(Large-Scale Particle Image Velocimetry) 이미지 분석 기법을 적용하였고, 잠제 주변의 역학적 특성을 파악하기 위해 평균수면 및 파고분포를 관측하였다. 수리실험을 통해 흐름패턴은 잠제에 의한 파고(파랑응력) 분포변화와 그에 따라 발달하는 잠제 후면과 측면 쇄파유도류 및 평균수면상승효과의 상호작용에 의해 변화됨을 알 수 있었다. 잠제 주변의 분기 또는 수렴하는 흐름패턴에 따라 각각 해안선 변동을 침식 또는 퇴적반응으로 구분하는 Ranasinghe et al.(2010)의 경험식과 수리실험 결과를 비교하여, 전반적으로 경험식에 부합하는 흐름패턴을 확인할 수 있었다. 그러나 일부 실험결과에서 기존의 경험식을 적용하여 구분하기 어려운 침식과 퇴적이 혼재된 반응을 유도하는 흐름패턴도 관찰할 수 있었다.

다국어 초록 (Multilingual Abstract)

In order to understand the efficacy of submerged breakwater constructed for the beach protection, laboratory experiments were carried out by observing the characteristics of flow around a single shore-parallel submerged breakwater. The velocity field near the shoreline was measured by utilizing the LSPIV (Large-Scale Particle Image Velocimetry) technique, and mean surface and wave height distributions were observed around the submerged breakwater, according to various combinations of incident waves and submerged breakwaters. In this experiment, it was found that the mean flow pattern behind the submerged breakwater was determined by the balance among the gradients of mean water surface and excess wave-momentum flux (i.e., radiation stress tensors) which interact with the wave-induced current developed by the gradients on the rear and the side of the submerged breakwater. The divergent and convergent flow patterns behind the submerged breakwater (i.e., accretion and erosion response) of the numerical study of Ranasinghe et al.(2010) were observed in the measured velocity distributions, and their empirical formula mostly agreed with the experimental results. However, for some cases in this experiment, it was difficult to say that the flow pattern was one of them and was agreed with the empirical formula.

목차 (Table of Contents)

• 요지
• Abstract
• 1. 서론
• 2. 실험 방법
• 3. 실험 결과
• 4. 결론 및 토의
• References

참고문헌 (Reference)

1 Kriebel, D. L., "Undistorted froude model for surf zone sediment transport" 20 : 1296-1310, 1986

2 Mei, C. C., "The applied dynamics of ocean surface waves" World Scientific 463-, 1989

3 Ranasinghe, R.S., "Shoreline response to submerged structures : a review" 53 : 65-79, 2006

4 Ranasinghe, R. S., "Shoreline response to multi-functional artificial surfing reefs : A numerical and physical modelling study" 53 : 589-611, 2006

5 Hanson, H., "Shoreline response to a single transmissive detached breakwater" 2034-2046, 1990

6 Ranasinghe, R. S., "Shoreline response to a single shore-parallel submerged breakwater" 57 : 1006-1017, 2010

7 Black, K.P., "Sandy shoreline response to offshore obstacles Part 1: salient and tombolo geometry and shape" 29 (29): 82-93, 2001

8 Douglass, S.L, "Performance of a perched beach - Slaughter beach, Delaware" 1385-1398, 1987

9 Zanuttigh, B., "Numerical modelling of the morphological response induced by low crested structures in Lido di Dante, Italy" 54 : 31-47, 2007

10 Rouse, H., "Nomogram for the settling velocity of spheres" National Research Council 57-64, 1937

11 Fujita, I., "Large-scale particle image velocimetry for flow analysis in hydraulic engineering applications" 36 (36): 397-414, 1998

12 Kantoush, S. A., "LSPIV implementation for environmental flow in various laboratory and field cases" 5 : 263-276, 2011

13 Martinelli, L., "Hydrodynamic and morphodynamic response of isolated and multiple low crested structures: experiments and simulations" 53 : 363-379, 2006

14 Heckbert, P. S., "Fundamentals of Texture Mapping and Image Warping" University of California 1989

15 Dean, R. G., "Full scale monitoring study of a submerged breakwater" 29 : 291-315, 1997

16 Lamberti, A., "European experience of low crested structures for coastal management" 52 : 841-866, 2005

17 Dean, R. G., "Equilibrium beach profiles: Principle and applications" 7 (7): 53-84, 1991

18 Villani, M., "Circulation patterns and shoreline response induced by submerged breakwaters" 2012

19 Ranasinghe, R.S., "Beach morphology behind single impermeable submerged breakwater under obliquely incident waves" 49 (49): 1-24, 2007

20 Deguchi, I., "Beach fill at two coasts of different configurations" 77 : 1032-1046, 1986

21 Zyserman, J., "Analysis of far-field erosion induced by low crested rubble mound structures" 52 : 977-994, 2005

22 Choi, J., "A laboratory experiment on beach profile evolution induced by two wave conditions dominated in the Haeundae Coast of Kore" 75 (75): 1327-1331, 2016