CFD-CSD NUMERICAL MODELLING OF WAVE-INDUCED PRESSURES IN OPEN- PORED PBA-REVETMENTS
AbstractThe highly porous Polyurethane Bonded Aggregates (PBA) revetments represent a novel ecologically friendly solution for the protection of shorelines and vulnerable coastal areas against erosion. Advantages of the open-pored PBA-revetments over conventional smooth impermeable revetments are among others, the reduction of: wave run- up/run-down, wave reflection and wave-induced loads on the sand core beneath the revetment. However, the hydro- geotechnical processes involved in the interaction of waves with such PBA-revetments and their foundation are still not sufficiently understood. Therefore, a new 3-dimensional one-way coupled CFD-CSD model system "wavePoreGeoFoam" was developed at the Leichtweiß-Institute (LWI) within the OpenFOAM® framework for the analysis of the response of open-pored PBA-revetments due to wave-induced loads. In this way, this paper firstly describes the new CFD-CSD model system. Second, validation of the model "wavePoreGeoFoam" is shown considering large-scale laboratory tests performed in the Large Wave Flume (GWK) at the Coastal Research Center (FZK) in Hanover, Germany (Oumeraci et al. 2010). Third, the relevance of implementing the CFD-CSD coupling for modelling wave-induced pressures on and beneath PBA-revetments is discussed. Fourth, a sensitivity analysis related to the effect of the empirically defined parameters for the numerical model is described. Finally, recommendations and implications of the use of CFD-CSD model for further research will be addressed.
Alcérreca Huerta, J.C., and H. Oumeraci. 2013. Model equations and validation tests of the numerical modelling of porous structures: focus on solvers developed within the OpenFOAM® framework, Internal Report, Leichtweiß-Institut fur Wasserbau, Technische Universität Braunschweig, Braunschweig, Germany, 137 pp.
Alcérreca Huerta, J.C. 2014. Process-based modelling of waves interacting with porous bonded revetments and their soil foundation, Ph.D. Thesis, Technische Universität Braunschweig, Germany, 200 pp.
BASF (2013). BASF Solutions-ELASTOCOAST. Retrieved August 13th, 2013 from http://www.basf.be
De Groot, M.B., M.D. Bolton, P. Foray, P. Meijers, A.C. Palmers, R. Sandven, A. Sawicki and T.C. Teh. 2006. Physics of liquefaction phenomena around marine structures, Journal of Waterways, Ports Coastal and Ocean Engineering, ASCE, 132(4), 227-243.
El Safti, H., and H. Oumeraci. 2012. Wave-structure-foundation interaction for gravity marine structures: the structural model, Internal report, Leichtweiß-Institut fur Wasserbau, Technische Universität Braunschweig, Braunschweig, Germany.
El Safti, H., M. Kudella and H. Oumeraci. 2012. Modelling wave-induced residual pore pressure and deformation of sand foundations underneath caisson breakwaters. Proceedings of 33rd International Conference on Coastal Engineering, Santander, Spain, 16pp.
El Safti, H., and H. Oumeraci. 2013. Modelling sand foundation behaviour underneath caisson breakwaters subject to breaking wave impact. Proceedings of 32nd International Conference on Ocean, Offshore and Arctic Engineering, ASME, 10pp. DOI:10.1115/OMAE2013-10281.
Engelund, F. 1953. On the laminar and turbulent flow of ground water through homogeneous sand, Report A.T.S. No. 3, Danish Academy of Technical Sciences, Technical University of Denmark.
Foyer, G. 2013. Prediction Formulae for processes on and in porous bonded revetments -An experimental and numerical study-, Ph.D. Thesis, Technische Universität Braunschweig, Germany, 164 pp.
Hsu, T.J., T. Sakakiyama, and P.L.F. Liu. 2002. A numerical model for wave motions and turbulence flows in front of a composite breakwater, Coastal Engineering, 46(1), 25-50. DOI: 10.1016/S0378-3839(02)00045-5.
Liebisch, S., J.C. Alcérreca Huerta, A. Kortenhaus, and H. Oumeraci. 2012. Bonded porous revetments -effect of porosity on wave-induced loads and hydraulic performance-. Proceedings of 33rd International Conference on Coastal Engineering, Santander, Spain, 15pp.
Morris, D.A., and I.A. Johnson. 1967. Summary of hydrologic and physical properties of rock and soil materials as analyzed by the Hydrologic Laboratory of the U.S. Geological Survey, USGS Water Supply Paper: 1839-D, U.S.A.
Oumeraci, H., T. Staal, S. Pfoertner, G. Ludwigs, and M. Kudella. 2010. Hydraulic performance, wave loading and response of Elastocoast revetments and their foundation -A large scale model study-. Report Nr. 988, Leichtweiß-Institut fur Wasserbau, Technische Universität Braunschweig, Braunschweig, Germany.
Sidiropolou, M.G., K.N. Moutsopoulos, and V.A. Tsihrintzis. 2006. Determination of Forchheimer equation coefficients a and b, Hydrological processes, 21, 534-554. DOI: 10.1002/hyp.6264.
Van Gent, M.R.A. 1993. Stationary and oscillatory flow through coarse porous media, Report 93-9, Communications on Hydraulic Geotechnical Engineering, Delft University of Technology, The Netherlands, 62 pp.
Zienkiewicz, O.C., A.H.C. Chan, M. Pastor, B.A. Schrefler, and T. Shiotmi. 1999. Computational geomechanics with special reference to earthquake engineering, John Wiley & Sons, Ltd., England, pp. 398.