|Source||CMES: Computer Modeling in Engineering & Sciences, Vol. 106, No. 4, pp. 263-289, 2015|
|Download||Full length paper in PDF format. Size = 929,422 bytes|
|Keywords||Rogue waves, random sea, 2nd order wave theory, FNPT, improved SBI, QALE-FEM.|
This paper presents an improved technique to generate rogue (freak) waves embedded in random sea based on the approach proposed by Kribel and Alsina (2000). In this method, a part of the wave energy is focused using the temporal-spatial focusing approach to generate an extreme transient wave and the rest behaves randomly. By introducing a correction term, the improved technique removes the numerical.ly spurious fluctuations of the spectra in the existing approach. Various effects of the correction are investigated numerically by using the second-order wave theory and two existing numerical. methods based on the fully nonlinear potential theory (FNPT), including the improved Spectral Boundary Integral (SBI) method and the Quasi Arbitrary Lagrangian- Eulerian Finite Element Method (QALE-FEM). The discussions are mainly focused on (1) the effectiveness of the correction on retaining the features of the specified wave spectrum; and (2) the effects of the correction on the probability of the maximum wave heights.