This paper numerically investigates breaking wave interaction with a vertical wall attached with a recurved parapet in 1:8 model scale, as part of the ISOPE-2022 comparative study. The in-house CFD solver naoe-FOAM-SJTU based on the open source platform OpenFOAM is used to perform all simulations. For wave generation, a novel generating-absorbing boundary condition (GABC) is adopted to replace the time-consuming moving boundary wavemaker. A geometric volume-of-fluid (VOF) method based on piecewise-linear interface calculation (PLIC) is incorporated in the present numerical model to capture the sharp interface and improve the accuracy of the predicted impact pressure. The time history and frequency analysis of the wave elevation and pressure at each probe are compared with the experimental data. The comparison demonstrates that the present numerical model is able to predict the impact pressure with sufficient accuracy but gives less accurate results of wave elevation. Moreover, the evolutions of free surface, pressure, and vorticity distribution are further provided to achieve a better understanding of this complex wave-structure interaction issue as a good complement to the experiments.
Vertical breakwaters are typical coastal structures intended to reduce the effects of incoming waves, especially in extreme sea conditions. In practical design, wave overtopping has been a significant issue of sustained concern for decades. Among the various solutions, a parapet fixed on the top of the vertical wall has been proven effective by deflecting back the up-rushing water seawards. However, according to previous studies, the shape and parameters of the parapet will significantly influence the impact force and pressure compared with the original vertical wall. To provide guidelines to predict the wave impact and wave loading, it is necessary to systematically investigate the variations under different wave conditions, including non-breaking and broken waves.