An efficient fully nonlinear diffraction model has been developed based on a time-domain higher-order boundary element method (HOBEM). An explicit description of incident waves is exploited to solve a modified problem for diffracted flow only. On the instantaneous free surface, a mixed Eulerian-Lagrangian (MEL) technique is used as the time marching process in a Lagrangian scheme. This approach possesses a number of practical advantages in terms of accuracy and computational efficiency. Numerical simulations are carried out for wave diffraction around a fixed vertical circular cylinder and verified by comparing with other published numerical and experimental results.
In recent years, considerable efforts have been made to the accurate prediction of nonlinear wave loads acting on structures in ocean and offshore industries. Most researches have been conducted based on the linear or higher-order perturbation analysis. The second- order analysis may represent a valuable alternative method in moderately steep waves. The applications of this method can be found in many publications, such as Eatock Taylor & Hung (1987), Isaacson & Cheung (1992), Isaacson & Ng (1993), Kim et al. (1997), and Teng et al. (1999, 2002). However, it is inaccurate for strong nonlinear waves. In the last two decades, the fully nonlinear numerical wave tank model has been widely applied to simulate wave-body interactions. Waves are generated by a wave maker, and their propagation and interaction with bodies are simulated as a single process, which can model real physical experiments. For example, Ma et al. (2001), Wu & Hu (2004), and Wang et al. (2007, 2010) developed a three-dimensional fully nonlinear numerical wave tank based on the finite element method (FEM). Grilli et al. (2001), Xue et al. (2001), and Bai & Eatock Taylor (2007, 2009) used the boundary element method (BEM) to calculate the similar problems.
