A novel method in generating freak wave and modulating wave profile

Abstract

More and more attentions have been paid on freak wave since it leads to serious damages on marine structures. The conventional method is to conduct linear superposition in frequency domain to obtain freak waves. In this study, the expected freak wave is firstly embedded in an irregular wave train and then transformed into frequency domain by Fast Fourier Transform (FFT). Because of the visualization and maneuverability in time domain, the profile of freak wave can be modulated conveniently. Therefore, special freak wave cases such as Three Sisters Wave (TSW), can also be obtained by this method. The correction on wave spectrum for freak wave train is firstly presented. It was then validated in experiments. The results show that the method is efficient to generate freak waves and TSW, and has good agreements in both time domain and frequency domain. The advantage of the proposed method is that the other waves can be maintained very well when modulating the profile of freak wave. The novel method is helpful to investigate the mechanism of freak wave-structures interaction in deep.