Generating shallow- and intermediate-water waves using a line-shaped mass source wavemaker

Abstract The mass source wavemaker in Navier–Stokes equations, which is a frequently used wave generation method, is relatively difficult to control. To resolve this problem, a line-shaped mass source wavemaker is proposed for generating shallow- and intermediate-water waves. Via employing reasonable simplifications, only the enhanced factor, which is introduced to compensate for the energy loss, is unknown during the wave generation process. It is derived that the enhanced factor depends on a weighted combination of wave steepness and relative water depth. Furthermore, the velocity field inside the source region is adjusted at each time step to eliminate the undesirable downward velocity which could contaminate the result via inducing strong and persistent vortical activities near source regions. With the undesirable velocity eliminated, the vortical activity in the vicinity of the source region is weakened significantly. Compared with other mass source wavemakers, the proposed method yields better results when it is used for simulating waves of large steepness. Compared with piston-type wavemakers, the proposed method yields satisfactory results when it is used for generating high-order waves although it is derived under the linear theory. Further simulations indicate that the proposed method is competent to reproduce the process of wave-structure interactions precisely.