A Numerical Wave Tank Based On OpenFOAM And Its Application

Waves have received considerable attention in the research of port and coastal engineering. Experiments, prototype observation, theoretic analysis and numerical simulation are major methods in the research, amongst which, numerical simulation has become more and more popular because of its wide application, convenience in adjustment, good compatibility with complex environment and lower costs compared to the experiments. In order to study the propagation and interaction with structure of the wave, a numerical wave tank based on open source software was built.A three dimensional numerical wave model which solves Navier-Stokes equation using finite volume method on unstructured mesh was built based on OpenFOAM, an open source computational fluid dynamics toolbox, with several turbulence models available. Volume of fluid method was employed to capture the free surface of the wave. The model reaches a comparatively high accuracy, based on which propagation and deformation of the wave can be well described. MPI was also employed to provide good compatibility with parallel computation.Base on the model, the 2D waves around pier structure was simulated using RNG model. The influence to wave propagation by piers with different submerged depth and width were evaluated and the variation of wave pressure on the front and bottom of the pier were also presented. The interaction between the wave and structure was discussed. Factors affecting the stability of the high pile pier structure were also discussed with a prototype simulation.A submerged dike was also simulated using large eddy simulation and the results were compared to a flow field PIV experiment. The generation and development of eddies around the dike was discussed and the three dimensional characteristic of the velocity and turbulence field was involved with analysis to the cross-section of the tank.Wave height dissipation in NWT was discussed and resolved. The computational characteristic of this NWT was also derived from log files of cases. Relationship between computation speed, mesh quality and computation settings was discussed. Some basic principles of improving stability and efficiency were concluded.