Fully nonlinear analysis of near-trapping phenomenon around an array of cylinders

Wave resonances in a narrow gap between two barges using fully nonlinear numerical simulation

“…More striking is the non-dimensionalised second-order wave elevation in Fig. 4(b), where results of both Bai et al [29] and the present model agree well with the experiments. The analytical solution of Malenica et al [27], however, tends to over-predict the second-order elevation near x = 0.366 m upwave of the downstream cylinder.…”

“…2 plots the non-dimensional time history of wave elevation at the center of the array. It can be seen that the present results are very close to those in Bai et al [29] (note that they have a phase shift as expected) after the steady states have been reached, yet a smaller number of wave periods is required for the present model to achieve the final steady state. A similar comparison is made in Fig.…”

“…A likely explanation for the small difference observed in Figs. 2 and 3 may be the side wall effects in the numerical model of Bai et al [29], while the current simulation is more suitable for open sea conditions. As in [29], we have used FFT techniques to extract from the time history of wave elevation several higher harmonics, as indicated in Fig.…”

“…The first, second and third harmonics are the components of fully nonlinear results at single-, double-, and triple the frequency of the incident wave, respectively. Analytical solutions by the secondorder potential theory in Malenica et al [27], numerical results in Bai et al [29] and experimental data from Ohl et al [28] are included in the comparisons. The first-order results in Fig.…”

“…This is the case tested in the experiments in Ohl et al [28] with an incident wave of steepness kA = 0.126, and here is simulated for comparison. More information on the near-trapping and the configurations of this case can be found in Bai et al [29]. In their analysis, where a rectangular numerical wave tank was adopted and the propagating monochromatic wave was generated by a piston-like wave maker, a long simulation time was required before the steady-state regime was achieved.…”