A 3D Numerical Wave Tank (NWT) has been implemented in the inhouse Large Eddy Simulation (LES) code to study wave-structure interaction problems in deep, intermediate and shallow water-depths. For the purpose of this study, a three dimensional solitary wave interacting with a submerged finite plate is considered. The direction of the wave relative to the plate orientation is examined by considering a rotating plate of several angles of attack (θ). The NWT is capable of generating solitary, linear and non-linear periodic waves using Dirichlet boundary conditions based on relevant wave theories. Experimental data obtained from a previous study of a solitary wave-fixed plate interaction are used to evaluate the accuracy of the refined code, by comparing wave elevations, forces and moments. Then, a finite plate of various angles of attack is considered and plots of the free-surface evolution and contours of the flow vorticity reveal the variations and similarities between different cases and confirm that complex local flow hydrodynamics exist in such more realistic problems.
Due to climate change and global worming, shorelines and coastal protection suffer from the impact of extreme events such as storms and extreme wave conditions. Breakwaters, wave energy converters and other near-coast structures are usually designed to operate in calm water conditions, however, under extreme conditions, they may experience high impact pressures and forces critical for the stability and durability of the design. Understanding the impact of extreme waves like tsunami waves on coastal structures will result to safer and more efficient designs.
Different theories have been adopted to develop numerical models to estimate the hydrodynamic properties in coastal engineering problems. Based on potential theory, Liu et al. (2009) consider regular waves propagating over a thin flat plate and good agreement with relevant experimental data achieved. Similarly, based on velocity potential Dong et al. (2018) examined the forces acting by monochromatic waves on a thin flat plate located over an uneven floor bed. Different bottom geometries were also tested to study their effect on wave reflections. Alternatively, Hayatdavoodi and Ertekin (2015a,b) based their numerical model in level 1 Green-Naghdi (GN) equations to study the interaction of solitary and regular waves with a submerged thin plate. Similar models such as Boussinesq-type models (Nwogu, 1993; Wei and Kirby, 1995) are widely used in coastal engineering problems. However, relevant experimental studies (Poupardin et al., 2012; Lo and Liu, 2014) revealed a dominant rotational flow near the edges of the submerged plate that alter the near-field hydrodynamics. Not all models are capable of accurately simulating the above. In a comprehensive review Hayatdavoodi and Ertekin (2016) presents the key studies relevant to waves interacting with bridge decks and flat plates.