Bjarne Jensen, Erik Damgaard Christensen, B. Mutlu Sumer


The present paper presents the results of an experimental and numerical investigation of the flow between large roughness elements on a steep sloping impermeable bed during wave action. The setup is designed to resemble a breakwater structure. The work is part of a study where the focus is on the details in the porous core flow and the armour layer flow i.e. the interaction between the two flow domains and the effect on the armour layer stability. In order to isolate the processes involved with the flow in the porous core the investigations are first carried out with a completely impermeable bed and successively repeated with a porous bed. In this paper the focus is on the impermeable bed. Results are obtained experimentally for flow and turbulence between the roughness elements on the sloping bed. Numerical simulations have reproduced the experimental results with good agreements and can hereby add more details to the understanding of the fluid-structure interaction.


Fluid-structure interaction; Breakwaters; Model scale experiments; Numerical modelling

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Andersen, T. L., Burcharth, H., and Gironella, X. (2011). Comparison of new large and small scale overtopping tests for rubble mound breakwaters. Coastal Engineering, 58(4):351–373.http://dx.doi.org/10.1016/j.coastaleng.2010.12.004

Burcharth, H. and Andersen, O. (1995). On the one-dimensional steady and unsteady porous flow equations. Coastal Engineering, 24(3-4):233–257.http://dx.doi.org/10.1016/0378-3839(94)00025-S

Burcharth, H., Kramer, M., Lamberti, a., and Zanuttigh, B. (2006). Structural stability of detached low crested breakwaters. Coastal Engineering, 53(4):381–394.http://dx.doi.org/10.1016/j.coastaleng.2005.10.023

Christensen, E. (2006). Large eddy simulation of spilling and plunging breakers. Coastal Engineering, 53(5-6):463–485.http://dx.doi.org/10.1016/j.coastaleng.2005.11.001

Christensen, E. D. and Deigaard, R. (2001). Large eddy simulation of breaking waves. Coastal Engineering, 42(1):53–86.http://dx.doi.org/10.1016/S0378-3839(00)00049-1

del Jesus, M., Lara, J. L., and Losada, I. J. (2012). Three-dimensional interaction of waves and porous coastal structures. Coastal Engineering, 64:57–72.http://dx.doi.org/10.1016/j.coastaleng.2012.01.008

Engelund, F. (1954). On the laminar and turbulent flows of ground water through homogeneous sand. Technical report, Danish Academy of Technical Sciences.

Grilli, B. S. T., Losada, M. A., and Martin, F. (1994). Characteristics of solitary wave breaking induced by breakwaters. Journal of Waterway, Port, Coastal, and Ocean Engineering, 120(1).http://dx.doi.org/10.1061/(ASCE)0733-950X(1994)120:1(74)

Grilli, S., Svendsen, I., and Subramanya, R. (1997). Breaking Criterion And Characteristics For Solitary Waves On Slope. Journal of Waterway, Port, Coastal, and Ocean Engineering, (June):102–112.http://dx.doi.org/10.1061/(ASCE)0733-950X(1997)123:3(102)

Hald, T. (1998). Wave Induced Loading and Stability of Rubble Mound Breakwaters. Series paper no. 18, Aalborg University.

Jensen, A., Pedersen, G. K., and Wood, D. J. (2003). An experimental study of wave run-up at a steep beach. Journal of Fluid Mechanics, 486:161–188.http://dx.doi.org/10.1017/S0022112003004543

Lai, J.-W., Hsu, T.-W., and Lan, Y.-J. (2010). Experimental and numerical studies on wave propagation over coarse grained sloping beach. In Coastal Engineering, pages 1–15.

Lara, J. L., del Jesus, M., and Losada, I. J. (2012). Three-dimensional interaction of waves and porous coastal structures. Coastal Engineering, 64:26–46.http://dx.doi.org/10.1016/j.coastaleng.2012.01.009

Losada, I., Lara, J., Christensen, E., and Garcia, N. (2005). Modelling of velocity and turbulence fields around and within low-crested rubble-mound breakwaters. Coastal Engineering, 52(10-11):887–913.http://dx.doi.org/10.1016/j.coastaleng.2005.09.008

Muttray, M. and Oumeraci, H. (2005). Theoretical and experimental study on wave damping inside a rubble mound breakwater. Coastal Engineering, 52(8):709–725.http://dx.doi.org/10.1016/j.coastaleng.2005.05.001

Pedersen, G. and Gjevik, B. (1983). Run-up of solitary waves. Journal of Fluid Mechanics, 135:283–299.http://dx.doi.org/10.1017/S0022112083003080

Sumer, B. M., Sen, M. B., Karagali, I., Ceren, B., Fredsø e, J. r., Sottile, M., Zilioli, L., and Fuhrman, D. R. (2011). Flow and sediment transport induced by a plunging solitary wave. Journal of Geophysical Research, 116(C1):1–15.http://dx.doi.org/10.1029/2010JC006435

Torum, A. (1994). Wave-induced foreces on armor unit on berm breakwaters. Journal of Waterway, Port, Coastal, and Ocean Engineering, 120(3):251–268.http://dx.doi.org/10.1061/(ASCE)0733-950X(1994)120:3(251)

Vanneste, D. and Troch, P. (2012). An improved calculation model for the wave-induced pore pressure distribution in a rubble-mound breakwater core. Coastal Engineering, 66:8–23.http://dx.doi.org/10.1016/j.coastaleng.2012.03.007

DOI: http://dx.doi.org/10.9753/icce.v33.waves.23