In this paper, an improved numerical wave tank based on OpenFOAM is developed for simulations of wave-current interaction. The ghost fluid method (GFM) is implemented to handle the interface jump conditions and eliminate the spurious velocities. The sharp interface is obtained by a fully coupled level set and volume of fluid method (CLSVOF). A modified generating-absorbing boundary condition (GABC) is employed to achieve high-efficiency wave simulations in the presence of uniform currents. At the same time, the stabilized SST k-ω turbulence model is adopted to solve the excessive numerical dissipation in long-time wave propagation. The present numerical model is validated by a benchmark experiment, demonstrating its accuracy in predicting wave elevation and velocity profile.
With the rapid development of high-performance computers, Computational Fluid Dynamics (CFD) has been extensively used in marine hydrodynamics. Compared with previous methods like potential flow theory, CFD is more suitable for simulating complex two-phase flows, where violent free surface and large-scale flow separation may coexist. In addition, more detailed flow field information can be provided for in-depth analysis of flow mechanisms.
Given these advantages, many researchers have developed their own two-phase CFD solvers to meet the growing demand for high-fidelity simulations. For the study of wave hydrodynamics, Bihs et al. (2016) developed a three-dimensional numerical wave tank REEF3D based on the level set method and the ghost cell immersed boundary method. To gain a better understanding of wave-structure interaction (WSI), Xie et al. (2020) extended their 3D two-phase flow code (Xdolphin3D) to large eddy simulations. The air-water interface is captured by the high resolution VOF scheme CICSAM, and complex geometries are handled by the Cartesian cut-cell method. Zong et al. (2021) combined their CIP-based numerical model with the adaptive mesh framework Afivo to simulate free-surface flow. The CIP method is used for the spatial discretization of the advection term, and the VOF method THINC/SW is employed for interface capturing. Ferro et al. (2022) developed a GFM-based two-phase solver based on the open source CFD platform OpenFOAM. The Ghost Fluid Method (GFM) is used to deal with interface jump conditions, and several algebraic VOF schemes are implemented to capture the interface instead of the original MULES algorithm.
