The present work describes the numerical approach used for the assessment of breaking waves impact on a vertical wall with a large recurved parapet, for which experiments were performed in Coastal Research Centre (ForschungsZentrum Küste, FZK), Hannover, Germany (Ravindar et al., 2018, 2019, 2021).
To perform these computations, the compressible multi-phase solver within the OpenFOAM numerical toolbox is presently combined with the waves2FOAM libraries to generate waves and resolve the Navier Stokes equations. Moreover, in these considered solvers, the free surface is treated using the Volume of Fluid (VoF) method and the pressure-velocity equations are solved thanks to the PIMPLE algorithm.
Different wave gauges and pressure probes are present in the experimental configuration that are used either as input parameters for our simulations and for the validation of our numerical results by numerical-experimental cross-comparisons.
Coastal structures are built to prevent land erosion and flooding. They can appear in different shapes, among which vertical breakwaters and sea walls are frequently used. However, these structures can be severely damaged when subjected to violent sea state conditions. Oumeraci et al. (1993) reported that breaking waves are the most significant cause of this damage but, on the other hand, they state that the prediction of design wave load conditions remains difficult. This means that accurate investigation of waves loading is a key factor for a safe design of coastal infrastructures.
Extreme wave loadings have been underlined both theoretically (e.g. Cooker & Peregrine, 1990) and experimentally (e.g. Kirgkoz 1982; Oumeraci et al. 1993; Hattori et al., 1994 and Bullock et al., 2007). Most of these studies gave a general classification of breaking wave loads on vertical and sloping sea walls. Besides, it has been proven that the shape of breakwaters has a large influence on the so-called wave impact pressure exerted on the structure, and the wave over-topping as well (Hull and Müller, 2002). In fact, nowadays, with the sea level rise due to global warming, rather than increasing the sea wall height, many researchers and engineers show that adding a parapet could be more efficient in mitigating the wave over-topping through discharging a part of seawater back into the sea.
