NUMERICAL ANALYSIS OF WAVE AND NEARSHORE CURRENT FIELDS AROUND LOW-CRESTED PERMEABLE DETACHED BREAKWATERS

Takeshi Nishihata, Yoshimitsu Tajima, Shinji Sato

Abstract


A Boussinesq type numerical model was developed which can simulate both wave fields and current fields around permeable detached breakwaters. The validity of the model was verified through measurements of waves and nearshore currents in hydraulic experiments investigating reflection and transmission capability. The porosity of the structure was accounted by a friction term incorporating turbulent resistance. The combination of turbulent friction model and anisotropic diffusion type wave breaking model was found to reproduce wave fields around the detached breakwaters and nearshore current fields behind the structures with a good accuracy.

Keywords


permeable breakwater; porous structure; numerical modeling

References


Anno, K., and T. Nishihata. 2010. Development on offshore structure with wave force reduction, Proceedings of 32th International Conference on Coastal Engineering, ASCE, 224.

Cruz, E., K. Shiba, M. Isobe and A. Watanabe. 1992. A Computational Method for two-dimensional nonlinear wave transformation over submerged permeable breakwaters, Proceedings of Coastal Engineering, JSCE, Vol.39, 621-625.http://dx.doi.org/10.2208/proce1989.39.621

Goda, Y., Y. Suzuki, Y. Kishira and O. Kikuchi. 1976. Estimation of incident and reflected waves in random wave experiments, Technical Note of PARI, No.248, 1-28.

Hirayama, K., and T. Hiraishi. 2004. Boussinesq modeling of wave breaking and run-up on a reef;1D, Proceedings of Coastal Engineering, JSCE, Vol.51, 11-15.http://dx.doi.org/10.2208/proce1989.51.11

Madsen, P. A, O. R. Sorensen and H. A. Schaffer. 1997. Surf zone dynamics simulated by a Boussinesq type model. Part 1. Model description and cross-shore motion of regular waves, Coastal Engineering, ASCE, 255-287.

Mizutani, N., T. Goto, and W. G. McDougal. 1995. Hybrid-type numerical analysis of wave transformation due to a submerged permeable structure and internal flow, Proceedings of Coastal Engineering, JSCE, Vol.42, 776-780.http://dx.doi.org/10.2208/proce1989.42.776

Nwogu, O.J. 1993. Alternative form of Boussinesq equations for nearshore wave propagation, Journal of waterways, Port, Coastal and Ocean Engineering, ASCE, Vol.119(6), 618.http://dx.doi.org/10.1061/(ASCE)0733-950X(1993)119:6(618)

Ranasinghe, R. S, S. Sato and Y. Tajima. 2009a. Modeling of waves & currents around porous submerged breakwaters, Coastal Dynamics, No.12.

Ranasinghe, R. S, S. Sato and Y. Tajima. 2009b. Boussinesq modeling of waves and currents over submerged breakwaters, APAC, Vol.13, 58-64.

Rojanokamthorn, S., M. Isobe, and A. Watanabe. 2007. Modeling of wave transformation on submerged breakwater, Proceedings of 22th International Conference on Coastal Engineering, ASCE, 1060-1073.

Shimozono, T., S. Sato, and M. Isobe. 2005. Control of nearshore current and beach deformation by submerged detached breakwater, Asian and Pacific Coast, Vol.13, 1139-1153.

Tajima, Y., M. Kozuka, K. Ooshima and Y. Moriya. 2006. Numerical study on the effect of porous submerged mound to dissipate non-breaking long waves, Proceedings of 30th International Conference on Coastal Engineering, ASCE, 5008-5020.

Tajima, Y., S. Sato, T. Shimozono and M. Isobe. 2007. Modeling of wave-induced current around submerged detached breakwaters, Proceedings of International Conference on Coastal Structures, ASCE, 725-736.

Van Gent, M. R. A. 1995. Porous flow through rubble-mound material, Journal of waterways, Port, Coastal and Ocean Engineering, ASCE, 121(3), 171-181.

Watanabe, A. and M. Dibajnia. 1988. A numerical model of wave deformation in surf zone, Coastal Engineering, ASCE, 578-587.


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