Fully nonlinear viscous wave generation in numerical wave tanks

A numerical method for simulating the complete physics of the fully nonlinear viscous wave generation phenomenon is presented. To accomplish this objective, the motion of a solid body representing the wave generating mechanism is modeled. In this paper, both the piston-type and flap-type wavemakers are simulated and the results of the model are compared with those of the experiments and analytics. The unsteady, two dimensional Navier–Stokes equations are solved in conjunction with the volume-of-fluid method for treating the free surface. A wide range of waves from linear to nonlinear generated by piston and flap-type wavemakers in intermediate and deep water cases are studied in this paper. The accuracy of the numerical results is verified by a comparison with the results of the wavemaker theory, the available experimental data in the literature, and the experiments preformed in this study. For the cases with small wave steepness, the numerical results agree well with the theoretical and experimental results for both the piston and flap-type wavemakers. However, for cases with large wave steepness, the numerical and experimental wave heights are slightly lower than the analytics. In both the piston and flap-type wavemakers, the numerical results are in good agreement with the measurements.

► A numerical model is developed for simulating viscous wave generation phenomenon.
► The motion of a solid body representing the wave generating mechanism is modeled.
► Piston-type and flap-type wavemakers in intermediate and deep water cases are studied.
► Experiments are performed using flap-type wavemaker in small and high wave steepness.
► The numerical results are validated by a comparison with experiments and analytics.