CFD investigations of wave interaction with a pair of large tandem cylinders

Wave forces and the flow field around cylinders placed in a periodic wave field are investigated with a numerical model using the Reynolds-averaged Navier-Stokes equations. The numerical model is validated by simulating the wave interaction with a single cylinder and comparing the numerical results with experimental data from a large scale experiment. Then, the wave interaction with a single large cylinder and a pair of large cylinders placed in tandem for different incident wave steepnesses is studied. The numerically calculated forces are compared with predictions from potential theory. The numerical results are seen to match the predictions at low incident wave steepness but differ at higher incident wave steepnesses. The wave diffraction pattern around the tandem cylinders for waves of low and high steepness is investigated and the evolution of a strong diffraction pattern is seen in the case of high steepness waves, which results in the difference between the wave forces predicted by potential theory and the numerical model at higher steepnesses.