Author(s): Ignacio Fernandez De Bobadilla; Maria Jesus Martin; Paloma Aberturas; Corrado Altomare; Alejandro J. C. Crespo; Jose M. Dominguez; Moncho Gomez-Gesteira

Linked Author(s): María Jesús Martín, Corrado Altomare

Keywords: SPH; Wave-structure interaction; Overtopping

Abstract: This work aims to prove the capability of the DualSPHysics model to reproduce the overtopping results obtained in CEDEX large-scale flume physical tests with vertical sea walls (CEDEX, 2018). The Smoothed Particle Hydrodynamics (SPH) is based on a Lagrangian description of fluid motion in which continuum properties are reformulated in terms of smoothed quantities at discrete locations named “particles”. SPH can be conveniently adopted to simulate free-surface flows and for capturing highly nonlinear behaviour of wave-structure interactions. The DualSPHysics code (Domínguez et al., 2021) is an open-source code developed to use SPH for real engineering problems and it will be used here. A physical test representing a standard vertical sea wall designed for the Mediterranean wave climate has been selected. In particular, the one with largest measured overtopping discharges and highest wave conditions falling within the limits imposed by generation theory for piston-type wavemaker will be simulated with the DualSPHysics model. A sensitivity analysis on the initial inter-particle distance, the smoothing length and piston transfer function (by means of a gain factor) have been carried out for model validation. The two first parameters are related to the numerical resolution and the distance for particle interactions, respectively. The gain factor is applied in the numerical model to amplify the magnitude of the piston displacement in order to compensate wave decay that is dependent on the wave steepness (Ursell et al., 1960). A good agreement between the experimental and numerical accumulative overtopping volume and relative overtopping rate is achieved with errors lower than 1%. Once the model is validated and calibrated, it has been applied for the same wave spectrum but developed using different wave time series, obtaining acceptable results within the forecasts provided by the EurOtop (2018). Finally, the same calibration was verified for other wave cases available in the physical campaign. This works presents the first attempt to apply SPH models to simulate long duration events (25 min) where the overtopping volume (few events) is measured with waves interacting against a vertical wall. References: CEDEX, 2018. Ensayos en modelo físico sobre una sección tipo convencional de dique vertical, Madrid. Domínguez JM, Fourtakas G, Altomare C, Canelas RB, Tafuni A, García-Feal O, Martínez-Estévez I, Mokos A, Vacondio R, Crespo AJC, Rogers BD, Stansby PK, Gómez-Gesteira M. 2021. DualSPHysics: from fluid dynamics to multiphysics problems. Computational Particle Mechanics. Ursell YS, Dean F, Yu RG. 1960. Forced small-amplitude water waves: a comparison of theory and experiment. J. Fluid Mech. 7, 3–52. EurOtop, 2018. Manual on wave overtopping of sea defences and related structures. An overtopping manual largely based on European research, but for worldwide application.

DOI: https://doi.org/10.3850/IAHR-39WC2521711920221401

Year: 2022